This is an example program that actually allows the car to race using the FRDM-TFC library!

Dependencies:   FRDM-TFC

Fork of TFC-RACING-DEMO by Daniel Hadad

Files at this revision

API Documentation at this revision

Comitter:
redxeth
Date:
Sun Apr 20 03:33:03 2014 +0000
Commit message:
Initial version

Changed in this revision

FRDM-TFC.lib Show annotated file Show diff for this revision Revisions of this file
Spices/Spices.cpp Show annotated file Show diff for this revision Revisions of this file
Spices/Spices.h Show annotated file Show diff for this revision Revisions of this file
common.cpp Show annotated file Show diff for this revision Revisions of this file
common.h Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r 98e98e01a6ce FRDM-TFC.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FRDM-TFC.lib	Sun Apr 20 03:33:03 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/emh203/code/FRDM-TFC/#b34924a05d60
diff -r 000000000000 -r 98e98e01a6ce Spices/Spices.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Spices/Spices.cpp	Sun Apr 20 03:33:03 2014 +0000
@@ -0,0 +1,1270 @@
+#include "mbed.h"
+
+#include "Spices.h"
+#include "common.h"
+#include "TFC.h"
+
+// camera params
+#define NUM_LINE_SCAN 128
+#define MAX_LINE_SCAN NUM_LINE_SCAN-1
+#define MIN_LINE_WIDTH  0
+#define MAX_LINE_WIDTH  15
+#define FILTER_ENDS 0                              // # of pixels at end of camera data to ignore; set to 0 for now, later make 15
+#define RANGE (NUM_LINE_SCAN - (2 * FILTER_ENDS))  // range of camera pixels to consider
+#define ERR_RATIO 0.85                             // ratio of max possible error to pixels (have to measure!)
+#define DER_RATIO 0.5                              // ratio for der threshold level (was 0.5 initially, may put back)
+
+// steer/servo params
+#define MAX_STEER_LEFT -0.51                       // value determined by demo mode 1 measure (have to be adjusted with every servo horn attach)
+#define MAX_STEER_RIGHT 0.39                       // value determined by demo mode 1 measure
+#define DT 0.02                                    // # MS of time between intervals (doesn't really matter)
+
+// logging parameters
+#define NUM_LOG_FRAMES 700                         // # of frames to log (when logging active) ~14 sec worth!
+
+// ******  for debug tuning   ******
+#define TUNE_SPEED 0.7
+#define TUNE_KP 0.008
+#define TUNE_KI 0
+#define TUNE_KD 0
+#define MIN_POWER 60                               // percent min power (estimating for a 2-ft turn => 24" / (24" + 6" car) = 4/5; speed of inner wheel is 20% lower worst case
+#define SPEED_ADJUST 4
+#define ABS_ERROR_THRESH 10                        // number of pixels line position offset before changing KP value
+#define CONTROL_METHOD 2                           // which control method to use
+
+
+// Drive/motor params
+// 0.4 way too slow!!  need to charge battery
+#define SUB_LIGHT_SPEED 0.5                        // moderate speed (value 0 to 1 sent to motors)
+#define LIGHT_SPEED 0.6                            // fast...
+#define RIDICULOUS_SPEED 0.7                       // faster...
+#define LUDICROUS_SPEED 0.9                        // faster still!
+#define MAX_POWER 100                              // percent max power (for speed adjustments)
+
+// algo params
+#define UNKNOWN_COUNT_MAX  50                      // max value to allow for unknown track conditions before killing engine
+#define STARTGATEFOUNDMAX  0                       // max value to allow for finding starting gate before killing engine
+#define STARTGATEDELAY     50                      // Delay before searching for starting gate to kill engine
+
+#define MMA8451_I2C_ADDRESS (0x1d<<1)              // address for accelerometer?
+
+
+/* CAR INTERFACE
+
+  DIP SWITCH:
+  -----------------------------------------------------------------
+  1 - ON: Run MCP below; OFF: Run Demo program (see main.cpp)
+  2 - ON: Log frame data to array
+  3 - ON: Risky race option; OFF: Conservative race option
+  4 - ON: Start Gate Kill Switch Active
+  
+  POTS
+  -----------------------------------------------------------------
+  0 - controls nothing at the moment
+  1 - controls nothing at the moment
+
+  PUSHBUTTONS  
+  -----------------------------------------------------------------
+  A -  START car race!
+  B -  END CAR RACE / (while holding down when 'log frame data' active will also output terminal data)
+  
+*/
+
+// LEARNING CAR CLUB 9/10/13: 
+// IP need to test-- get around U turns -- more aggressive proportional control?  Or derivative?  Have camera look farther ahead but not too far ahead
+// IP need to test -- fix lighting for tunnels (if good algo doesn't need lighting!!)
+// -- increase power up to get up hills, brake down hills (accel: http://mbed.org/users/SomeRandomBloke/code/MMA8451Q/#)
+// -- add speed control? (hall effect sensor)
+// DONE -- make sure steering won't go past limits!!
+// 9/12/13 - adjust camera exposure time based on maximum light intensity!!
+// 9/14/13 - DONE -- make derivative threshold related to maximum light intensity!
+// 9/16/13 - crash at car club blew out resistor R8, replaced it and getty twitching when powering servo from USB only.  Ok when powering from battery.
+// 9/17/13 - experiments show that derivative control just doesn't work very well-- the tinest error delta causes huge drastic changes, need to use non-linear proportional
+//           control instead... parabolic??
+//           DONE -- Also need to slow down on curves
+//           speed up hills and slow down on downhill...
+//           measure speed?
+// 9/18/13 - Test track work: doesn't appear to be sampling camera fast enough--  not able to handle the wiggly track and sometimes not able to handle the curves!
+//           TODO: Need to increase rate at which camera sampled and decisions are made!!  Look to codewarrior code
+//           Need to cut off left/right ends of camera data-- seems to not read line properly in well lit rooms
+//           DONE Speed adjust as you go round; Need to have it slow down "into" curve, speed up again "out of curve"
+// 9/23/13 - Definitely not processing camera fast enough-- seems to not react well when speed up the car.  Goes slow just fine all the way 'round.
+//           TODO: Need to see how often TFC_LineScanImageReady gets updated. If update camera sample freq how will that impact exposure? Light adjustment algos should
+//           be able to handle it. Need to be able to measure the 'processing time' required.  Also wondering if 20mS is fast enough for updating the servo?? Need
+//           to calculate how fast servo needs to really go based on track curves and speed.
+//           TODO: Need a way to measure speed I think as well.
+//           TODO: Need to control speed differentially across the different motors!! See Eli video!!
+//           TODO: Use this to get excel feedback quicker: http://strokescribe.com/en/serial-port-download.html  (Doesn't work too well-- prefer my own excel method)
+//           TODO: Use PID control for steering!
+//           TODO: Use Speed control (PID?) --- add speed sensor!
+// 10/8/13   Reduced speed control to 90% (was 85%)-- seems to go off track and lose line at high speed-- mainly on the U turns
+//           Need to figure out why derivative control in steering doesn't work well.  Add integral control.
+//           Latest track times (no hill, no bumps, no tunnel, only squiggles) = 11.8sec at high speed with speed control
+//           Losing time on the curves-- need to optimize!!
+//           Worry about hill later-- need to get track times down around 8sec first.
+//        *****************************
+//        ** Implement some method to acount for U-TURNS on track-- and to help even go beyond what camera can see as far as estimating line position
+//        ** (U-TURNS take the longest time out of track)
+//        ** Method to help find the line even when not really visible
+//        *****************************
+// 10/17/13
+//        NEED CURVE AND WIGGLE DETECT!!
+// 10/20/13  Added logging capability and 'algo time' detect
+//           It is not finding the line on the edges when on a curve-- likely because my line detect algo requires both edges
+//           TODO-- need method that can use only one edge!
+
+// TODO LIST
+// - Speed Control via Sensor WAITING ON SENSOR
+// - Differential drive around curves DONE -- still trying to figure out what %age to drop on turns
+// - Full PID steering control IN PROGRESS
+// - Starting gate kill engine debug IN PROGRESS -- need to add delay
+// - Off track kill engine debug -- IN PROGRESS-- seems to kill car prematurely
+
+// image processing vars
+uint16_t   GrabLineScanImage0[NUM_LINE_SCAN];      // snapshot of camera data for this 'frame'
+float      DerivLineScanImage0[NUM_LINE_SCAN];     // derivative of line scan data
+float      NegEdges[NUM_LINE_SCAN];                // array-- set of where in line scan data negative edges found
+float      PosEdges[NUM_LINE_SCAN];                // array-- set of where in line scan data positive edges found
+uint16_t   numNegEdges = 0, numPosEdges = 0;       // max value of valid neg and positive indices (also serves as a count of # edges found)
+uint16_t   MaxLightIntensity = 0;                  // max measured light intensity -- to account for lighting differences
+uint16_t   MinLightIntensity = (1 << 12);          // min measured light intensity -- to account for lighting differences
+float      maxDerVal = 0;                          // max deriv value
+float      minDerVal = (float) (1 << 12);          // min deriv value
+float      aveDerVal = 0;                          // average deriv value
+float      DerivThreshold = (1 << 9);              // Derivative Threshold (default)
+float      PosDerivThreshold = (1 << 9);           // Pos Edge Derivative Threshold (default)
+float      NegDerivThreshold = (1 << 9);           // Neg Edge Derivative Threshold (default)
+
+
+// Steering control variables
+float      CurrentLinePosition;                    // Current position of track line (in pixels -- 0 to 127)
+float      LastLinePosition;                       // Last position of track line (in pixels -- 0 to 127)
+float      CurrentLinePosError = 0;                // Current line position error (used for derivative calc)
+float      AbsError;
+float      LastLinePosError = 0;                   // Last line position error (used for derivative calc)
+float      SumLinePosError = 0;                    // Sum of line position error (used for integral calc)
+float      DerivError = 0;                         // Derivative of error
+float      CurrentSteerSetting = (MAX_STEER_RIGHT + MAX_STEER_LEFT) / 2;  // drive straight at first
+float      CurrentLeftDriveSetting = 0;            // Drive setting (left wheel)
+float      CurrentRightDriveSetting = 0;           // Drive setting (right wheel)
+
+// Speed control vars
+float      MaxSpeed;                                    // maximum speed allowed
+
+uint16_t   startRaceTicker;                        // ticker at start of race1
+
+// Custom Data Types
+typedef enum TrackStatusType {Unknown,
+                              LineFound,
+                              StartGateFound,
+                              LineJustLeft} TrackStatusType;
+                              
+TrackStatusType CurrentTrackStatus;                // current track status
+TrackStatusType LastTrackStatus;                   // last track status                       
+
+/* typedef enum TrackType {NotSure,
+                        Straight,
+                        Curve,
+                        Wiggle,
+                        Bumps,
+                        StartGate,
+                        UpHill,
+                        DownHill} TrackType;
+
+TrackType CurrentTrack; */
+
+
+struct LogData {
+  float linepos;
+  float steersetting;
+  float leftdrivesetting;
+  float rightdrivesetting;
+};
+
+LogData    frameLogs[NUM_LOG_FRAMES];              // array of log data to store  
+int        logDataIndex;                           // index for log data
+
+
+int        StartGateFoundCount = 0;                // how many times start gate has been found
+int        UnknownCount = 0;                       // how many times nothing has been found (to help with kill switch implementation)
+bool       go = false;                             // Car can go!  Should be set to false to start.
+
+// EXTRA CONTROL PARAMETERS
+bool debugFakeMode = false;         // if true, ignores real camera and uses fake camera input instead; used for data processing debug
+int terminalOutput = 0;             // set debug level for terminal output
+                                    //    0 : no terminal output, race!
+                                    //    1 : output just to measure frame rate
+                                    //    2 : output for measuring time of operations
+                                    //    3 : output with delay
+bool doLogData = false;             // whether to capture log data to output later on
+bool killSwitch = false;             // whether to enable Kill Switch (allow engine to stop after not finding track)
+bool startGateStop = false;         // whether to stop or not depending on starting gate reading
+bool doRisky = false;               // race style-- whether conservative or risky
+
+// timer stuff
+Timer timer;
+int after_time, before_time, start_time, last_start_time;
+bool run_once = false;
+
+void MasterControlProgram()
+{
+
+  // put here all things want to run only once after reset
+  if (!run_once){
+    if ((terminalOutput == 1) || (terminalOutput == 2)){
+      timer.start();
+    }
+    run_once = true;
+  }
+  
+  // read DIP switches and Pots for data
+  readSwitches();
+                                                          
+  // Every 4s (or Terminal Output is off, i.e. race mode!)
+  //    AND line scan image ready (or fake mode where image is always ready)
+  //   (ticker updates every 2ms) (Line scan image ready very 20mS?)
+  if((TFC_Ticker[0]>2000 || (terminalOutput != 3)) && (TFC_LineScanImageReady>0 || debugFakeMode))
+   {
+
+     // stuff that needs to be reset with each image frame
+     if (terminalOutput == 1) {
+       last_start_time = start_time;
+       start_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:Between frames:%d:uSec\r\n", start_time - last_start_time);
+       before_time = timer.read_us();
+     }
+     TFC_Ticker[0] = 0;
+     TFC_LineScanImageReady=0; // must reset to 0 after detecting non-zero
+     MaxLightIntensity = 0;                  // reset
+     MinLightIntensity = (1 << 12);          // reset
+
+     // grab camera frame
+     grabCameraFrame();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER grabCameraFrame:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     }
+  
+     // calcalate derivative of linescandata, filter starttime data
+     derivativeLineScan(&GrabLineScanImage0[0], &DerivLineScanImage0[0]);
+
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER derivativeLineScan:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     }
+            
+     // adjust deriv threshold based on max lighting value
+     // has to be called before find edges
+     adjustLights();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER adjustLights:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     } 
+         
+     //find edges from derivative data
+     findEdges_v2(&DerivLineScanImage0[0]);
+
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER findEdges_v2:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     } 
+     
+     // turn on terminal output if line not found -- FOR DEBUG
+     //if (CurrentTrackStatus == Unknown)
+     //  terminalOutput = 1;
+
+     //review edge data and set position or starting flag appropriately
+     reviewEdges();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER reviewEdges:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     }      
+    
+     if (terminalOutput == 3) {
+       // print data to Terminal for camera 0
+       printLineScanData(&GrabLineScanImage0[0]);
+
+     // print deriviative of linescandata, filter starttime data
+       printDerivLineScanData(&DerivLineScanImage0[0]);
+       
+       printAdjustLightsData();
+       
+       printEdgesFound();
+
+     }
+     
+     // ** Track Status available at this point **  
+      
+     
+     // test out accelerometer
+    // accelTest();
+      
+     // Update things based on latest track status
+     // e.g. change steering setting, stop car, ...
+     ActOnTrackStatus();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER ActOnTrackStatus:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     }      
+
+
+     //give LED feedback as to track status
+     feedbackLights();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER feedbackLights:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();       
+     }  
+     
+     // control max power (speed)
+     SpeedControl();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER SpeedControl:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     }       
+
+     // Drive!!     
+     Drive();
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME:TO AFTER Drive:%d:uSec\r\n", after_time - before_time);
+       before_time = timer.read_us();
+     }         
+     
+     // wait_ms(1);
+
+     // Capture Log data while driving
+     if (go && doLogData) {
+       captureData();
+     }
+     
+     // Dump Log data to Terminal while stopped and holding B button
+     if (!go && doLogData && TFC_PUSH_BUTTON_1_PRESSED) {
+       dumpData();
+     }
+     
+     if (terminalOutput == 2) {
+       after_time = timer.read_us();
+       TERMINAL_PRINTF("TIME: ENTIRE FRAME (include prints):%d:uSec\r\n", after_time - start_time);
+       before_time = timer.read_us();
+     }
+
+     if (terminalOutput == 3) {
+       TERMINAL_PRINTF("\r\n**************************END********************************\r\n");
+     }
+
+   } 
+}
+
+void dumpData()
+{
+   TERMINAL_PRINTF("INDEX,LINEPOS,STEERSETTING,LEFTDRIVESETTING,RIGHTDRIVESETTING\r\n");
+       for(logDataIndex=0;logDataIndex<NUM_LOG_FRAMES;logDataIndex++) {
+         TERMINAL_PRINTF("%d,%6.2f,%6.2f,%6.2f,%6.2f\r\n",logDataIndex,frameLogs[logDataIndex].linepos,frameLogs[logDataIndex].steersetting,frameLogs[logDataIndex].leftdrivesetting,frameLogs[logDataIndex].rightdrivesetting);
+       }
+}
+
+void captureData()
+{
+  frameLogs[logDataIndex].linepos = CurrentLinePosition;
+  frameLogs[logDataIndex].steersetting = CurrentSteerSetting;
+  frameLogs[logDataIndex].leftdrivesetting = CurrentLeftDriveSetting;
+  frameLogs[logDataIndex].rightdrivesetting = CurrentRightDriveSetting;
+
+  // increment index                
+  logDataIndex++;
+  if (logDataIndex > NUM_LOG_FRAMES) 
+    logDataIndex = 0;
+}
+
+void readSwitches()
+{
+
+  // ********* GATHER DIP SWITCH INPUTS *********
+  if(TFC_GetDIP_Switch()&0x02)     // SWITCH 2 
+    doLogData = true;              // Log data to array
+  else
+    doLogData = false;             // normal operation
+  
+  if(TFC_GetDIP_Switch()&0x04)     // SWITCH 3
+    doRisky = true;     
+  else
+    doRisky = false;          
+    
+  if(TFC_GetDIP_Switch()&0x08)     // SWITCH 4 control start stop gate
+    startGateStop = true;
+  else
+    startGateStop = false;
+
+
+}
+
+void grabCameraFrame()
+{
+  uint32_t i = 0;
+  uint8_t fake_type = 4;                   // type of fake data if used
+
+  for(i=0;i<NUM_LINE_SCAN;i++) // print one line worth of data (128) from Camera 0
+  { 
+  
+    if (debugFakeMode) {                   // use fake camera data
+      switch (fake_type) {
+      case 0:                              // ideal track -- line in center
+         if (i<57 || i > 70)
+           GrabLineScanImage0[i] = 0xFFF;  // no line
+         else
+           GrabLineScanImage0[i] = 0x4B0;  // line
+         break;
+      case 1:                              // ideal track -- line to the left
+         if (i<27 || i > 40)
+           GrabLineScanImage0[i] = 0xFFF;  // no line
+         else
+           GrabLineScanImage0[i] = 0x4B0;  // line
+         break;
+      case 2:                              // ideal track -- line to the right
+         if (i<87 || i > 100)
+           GrabLineScanImage0[i] = 0xFFF;  // no line
+         else
+           GrabLineScanImage0[i] = 0x4B0;  // line
+         break; 
+      case 3:                              // ideal track -- starting gate!
+         // TBD
+         break;              
+      case 4:                              // less than ideal track -- debug multi-edge issue!
+         if (i<54)
+           GrabLineScanImage0[i] = 4000;   // no line
+         if (i == 54)
+           GrabLineScanImage0[i] = 3370;   // neg edge
+         if (i == 55)
+           GrabLineScanImage0[i] = 3309;   // neg edge
+         if (i == 56)
+           GrabLineScanImage0[i] = 2016;   // neg edge
+         if (i == 57)
+           GrabLineScanImage0[i] = 711;    // neg edge
+         if (i == 58)
+           GrabLineScanImage0[i] = 696;    // neg edge
+         if ((i>58) && (i<69))
+           GrabLineScanImage0[i] = 500;    // line
+         if (i == 69)
+           GrabLineScanImage0[i] = 1800;   // pos edge
+         if (i > 69)
+           GrabLineScanImage0[i] = 4000;   // no line
+      default:
+         break;
+      }
+    
+    } else {                               // use real camera data
+      GrabLineScanImage0[i] = TFC_LineScanImage0[i];
+    }
+  }
+
+
+}
+
+void printLineScanData(uint16_t* LineScanData)
+{
+  uint32_t i = 0;
+  float Val;
+
+  TERMINAL_PRINTF("LINE SCAN DATA:,");
+
+  for(i=0;i<NUM_LINE_SCAN;i++) // print one line worth of data (128) from Camera 0
+  { 
+    if (1 == 1) { // use float to print
+      Val = (float) LineScanData[i];
+      TERMINAL_PRINTF("%9.3f",Val);
+      if(i==MAX_LINE_SCAN)  // when last data reached put in line return
+        TERMINAL_PRINTF("\r\n");
+      else
+        TERMINAL_PRINTF(",");
+    } else {         
+      TERMINAL_PRINTF("0x%X",LineScanData[i]);
+      if(i==MAX_LINE_SCAN)  // when last data reached put in line return
+        TERMINAL_PRINTF("\r\n",LineScanData[i]);
+      else
+        TERMINAL_PRINTF(",",LineScanData[i]);
+      }
+  }
+
+}
+
+void printDerivLineScanData(float* derivLineScanData)
+{
+  uint32_t i, minCnt = 0, maxCnt = 0;
+  
+  minCnt = FILTER_ENDS;
+  maxCnt = NUM_LINE_SCAN - FILTER_ENDS;
+
+  TERMINAL_PRINTF("DERIVATIVE DATA:,");
+
+  for(i=minCnt;i<maxCnt;i++) // print one line worth of data (128) from Camera 0
+  {          
+    TERMINAL_PRINTF("%9.3f",derivLineScanData[i]);
+    if(i==maxCnt-1)          // when last data reached put in line return
+      TERMINAL_PRINTF("\r\n",derivLineScanData[i]);
+    else
+      TERMINAL_PRINTF(", ",derivLineScanData[i]);
+  }
+
+}
+
+void derivativeLineScan(uint16_t* LineScanDataIn, float* DerivLineScanDataOut)
+{
+
+  uint32_t i, minCnt = 0, maxCnt = 0;
+  float DerVal, upperDerVal, lowerDerVal = 0;
+  
+  maxDerVal = 0;
+  minDerVal = (float) (1 << 12);
+  aveDerVal = 0;
+  
+  minCnt = FILTER_ENDS;
+  maxCnt = NUM_LINE_SCAN - FILTER_ENDS;
+
+  // TERMINAL_PRINTF("i, upperDerVal, lowerDerVal, DerVal\r\n");
+  
+  for(i=minCnt;i<maxCnt;i++) // print one line worth of data from Camera 0
+  {  
+
+     // store max light intensity value
+     if (LineScanDataIn[i] > MaxLightIntensity)
+       MaxLightIntensity = LineScanDataIn[i];
+
+     // store min light intensity value
+     if (LineScanDataIn[i] < MinLightIntensity)
+       MinLightIntensity = LineScanDataIn[i];
+       
+
+     // Central Derivative
+     if (i==minCnt) {                       // start point
+       upperDerVal = (float)(LineScanDataIn[i+1]);
+       lowerDerVal = (float)(LineScanDataIn[i]);  // make same as start point
+     } else if (i==maxCnt - 1){             // end point
+       upperDerVal = (float)(LineScanDataIn[i]);   // make same as end point
+       lowerDerVal = (float)(LineScanDataIn[i-1]);
+     } else {                               // any other point
+       upperDerVal = (float)(LineScanDataIn[i+1]);
+       lowerDerVal = (float)(LineScanDataIn[i-1]);
+     }
+     DerVal = (upperDerVal - lowerDerVal) / 2;
+   //  TERMINAL_PRINTF("%d,%9.3f,%9.3f,%9.3f\r\n", i, upperDerVal, lowerDerVal, DerVal);
+            
+     if (DerVal > maxDerVal) {
+       maxDerVal = DerVal;
+     } 
+     if (DerVal < minDerVal) {
+       minDerVal = DerVal;
+     }
+     aveDerVal = aveDerVal + DerVal;           //get sum
+     DerivLineScanDataOut[i] = DerVal;    
+  }
+  aveDerVal = (float) aveDerVal / (maxCnt - minCnt);
+}
+
+//Not reliable for finding edges!
+void findEdges(float* derivLineScanData)
+{
+  // search for edges in deriviative data using a threshold
+  // need to store in a hash if that's possible...
+  // combine edges that are a pixel apart
+ 
+  int i, minCnt = 0, maxCnt = 0;
+  int multiNegEdgeCnt = 1, multiNegEdgeSum = 0;
+  int multiPosEdgeCnt = 1, multiPosEdgeSum = 0;
+      
+  minCnt = FILTER_ENDS;
+  maxCnt = NUM_LINE_SCAN - FILTER_ENDS;
+  
+  numNegEdges = 0;
+  numPosEdges = 0;
+  for(i=minCnt;i<maxCnt;i++) // print one line worth of data from Camera 0
+  {  
+     if (derivLineScanData[i] <= NegDerivThreshold)     // NEGATIVE EDGE FOUND!
+     {
+       if (terminalOutput == 3) {
+         TERMINAL_PRINTF("NEG EDGE FOUND AT INDEX %d WITH VALUE %9.3f\r\n", i, derivLineScanData[i]);
+       }
+       
+       if ((numNegEdges > 0) && (NegEdges[numNegEdges - 1] + 1 == i )) // if no multi edges
+       {  // edge actually across multiple pixels
+         multiNegEdgeCnt++;
+         multiNegEdgeSum = multiNegEdgeSum + i;
+         if (terminalOutput == 3) {
+           TERMINAL_PRINTF("MULTIEDGE FOUND! MultiNegEdgeCnt: %d; MultiNegEdgeSum: %d\r\n", multiNegEdgeCnt, multiNegEdgeSum);
+         }
+       } else {  // not a multi-pixel edge known at this time, store negative edge index value
+         numNegEdges++;
+         if (terminalOutput == 3) {
+           TERMINAL_PRINTF("NEG EDGE STORED WITH INDEX %d.  NUM NEG EDGES = %d\r\n", i, numNegEdges);
+         }
+         NegEdges[numNegEdges - 1] = (float) i;
+         multiNegEdgeSum = i;
+       }
+ 
+ 
+     } else if (derivLineScanData[i] > PosDerivThreshold) {    // POSITIVE EDGE FOUND!
+     
+       if (terminalOutput == 3) {
+         TERMINAL_PRINTF("POS EDGE FOUND AT INDEX %d WITH VALUE %9.3f\r\n", i, derivLineScanData[i]);
+       }
+       
+       if ((numPosEdges > 0) && (PosEdges[numPosEdges - 1] + 1 == i ))
+       {  // edge actually across multiple pixels
+         multiPosEdgeCnt++;
+         multiPosEdgeSum = multiPosEdgeSum + i;
+         if (terminalOutput == 3) {
+           TERMINAL_PRINTF("MULTIEDGE FOUND! MultiPosEdgeCnt: %d; MultiPosEdgeSum: %d\r\n", multiPosEdgeCnt, multiPosEdgeSum);
+         }
+       } else {  // not a multi-pixel edge known at this time, store Posative edge index value
+         if (terminalOutput == 3) {
+           TERMINAL_PRINTF("POS EDGE STORED WITH INDEX %d.  NUM POS EDGES = %d\r\n", i, numPosEdges);
+         }
+         numPosEdges++;
+         PosEdges[numPosEdges - 1] = (float) i;
+         multiPosEdgeSum = i;
+       }      
+       
+     }  else {  // NO EDGE FOUND
+       // combine multi-edges if there are any
+       if (multiNegEdgeCnt > 1)
+       { 
+          NegEdges[numNegEdges - 1] = (float) multiNegEdgeSum / multiNegEdgeCnt;
+          multiNegEdgeCnt = 1; multiNegEdgeSum = 0;
+       }
+       if (multiPosEdgeCnt > 1)
+       { 
+          PosEdges[numPosEdges - 1] = (float) multiPosEdgeSum / multiPosEdgeCnt;
+          multiPosEdgeCnt = 1; multiPosEdgeSum = 0;
+       }       
+     
+     }
+  }
+
+}
+
+
+void findEdges_v2(float* derivLineScanData)
+{
+  // search for edges in deriviative data using a threshold
+  // need to store in a hash if that's possible...
+  // combine edges that are a pixel apart
+ 
+  int i;
+  
+  int NegEdgeBufCnt = 0, NegEdgeBufSum = 0;     // serves as buffer to store neg edges found next to each other
+  int PosEdgeBufCnt = 0, PosEdgeBufSum = 0;     // serves as buffer to store pos edges found next to each other
+      
+  int minCnt = FILTER_ENDS;
+  int maxCnt = NUM_LINE_SCAN - FILTER_ENDS;
+  
+  
+  
+  numNegEdges = 0;                              // count of neg edges found thus far
+  numPosEdges = 0;                              // count of pos edges found thus far
+  for(i=minCnt;i<maxCnt;i++) // print one line worth of data from Camera 0
+  {  
+     
+     if (derivLineScanData[i] <= NegDerivThreshold)          // NEGATIVE EDGE FOUND!
+     {
+       
+       if (terminalOutput == 3) {
+         TERMINAL_PRINTF("NEG EDGE FOUND AT INDEX %d WITH VALUE %9.3f\r\n", i, derivLineScanData[i]);
+       }
+
+       NegEdgeBufCnt++;                                      // add value to neg edge buffer
+       NegEdgeBufSum = NegEdgeBufSum + i;
+       
+     } else if (derivLineScanData[i] > PosDerivThreshold) {  // POSITIVE EDGE FOUND!
+       
+       if (terminalOutput == 3) {
+         TERMINAL_PRINTF("POS EDGE FOUND AT INDEX %d WITH VALUE %9.3f\r\n", i, derivLineScanData[i]);
+       }
+
+       PosEdgeBufCnt++;                                      // add value to pos edge buffer
+       PosEdgeBufSum = PosEdgeBufSum + i;
+       
+     }  else {                                               // NO EDGE FOUND
+         
+       // POP EDGE BUFFERS IF NON-EMPTY AND STORE TO EDGE "STACK" (i.e. edges found)
+       
+       if (NegEdgeBufCnt > 0) {
+         // store edge value
+         numNegEdges++;
+         NegEdges[numNegEdges - 1] = (float) NegEdgeBufSum / NegEdgeBufCnt;
+         
+         // clear edge buffer      
+         NegEdgeBufSum = 0; NegEdgeBufCnt = 0;
+       }
+
+       if (PosEdgeBufCnt > 0) {
+         // store edge value
+         numPosEdges++;
+         PosEdges[numPosEdges - 1] = (float) PosEdgeBufSum / PosEdgeBufCnt;
+         
+         // clear edge buffer
+         PosEdgeBufSum = 0; PosEdgeBufCnt = 0;
+       }        
+     
+     }
+     
+  }
+
+}
+
+void printEdgesFound()
+{
+  int i;
+  
+    // Check that neg edges captured ok
+    TERMINAL_PRINTF("NEGATIVE EDGES FOUND:,");
+    for(i=0;i<=numNegEdges-1;i++)
+    {
+      TERMINAL_PRINTF("%9.3f",NegEdges[i]);
+      if(i==numNegEdges-1)              // when last data reached put in line return
+        TERMINAL_PRINTF("\r\n");
+      else
+        TERMINAL_PRINTF(", ");
+    }
+  
+  
+    // Check that pos edges captured ok
+    TERMINAL_PRINTF("POSITIVE EDGES FOUND:,");
+    for(i=0;i<=numPosEdges-1;i++)
+    {
+      TERMINAL_PRINTF("%9.3f",PosEdges[i]);
+      if(i==numPosEdges-1)              // when last data reached put in line return
+        TERMINAL_PRINTF("\r\n");
+      else
+        TERMINAL_PRINTF(", ");
+    }
+
+}
+
+void reviewEdges()
+{
+  LastTrackStatus = CurrentTrackStatus;
+  
+  if ((numPosEdges == 1) && (numNegEdges == 1))  // only one negative and positive edge found (LINE)
+  {
+    if (((PosEdges[0] - NegEdges[0]) >= MIN_LINE_WIDTH) && ((PosEdges[0] - NegEdges[0]) <= MAX_LINE_WIDTH)) // has proper expected width
+    {
+       CurrentTrackStatus = LineFound;                                   // report line found!
+       UnknownCount = 0;                                          // reset unknown status count
+       LastLinePosition = CurrentLinePosition;
+       CurrentLinePosition = (PosEdges[0]+NegEdges[0]) / 2;       // update line position
+    }
+  } else if ((numPosEdges == 1) && (numNegEdges == 0))  {     // 1 pos edge found (POSSIBLE LINE)
+    if ((PosEdges[0] <= MAX_LINE_WIDTH) && (LastLinePosError < 0))       // pos edge is within line width of edge of camera (LEFT)
+    {
+       CurrentTrackStatus = LineFound;                                   // report line found!
+       UnknownCount = 0;                                                 // reset unknown status count
+       LastLinePosition = CurrentLinePosition;
+       CurrentLinePosition = PosEdges[0] - ( MAX_LINE_WIDTH / 2);        // update line position
+     //  TERMINAL_PRINTF("*** SINGLE POSEDGE LINE FOUND AT POSITION %9.3f *** \r\n", CurrentLinePosition);
+    }
+  } else if ((numNegEdges == 1) && (numPosEdges == 0))  {     // 1 neg edge found (POSSIBLE LINE)
+    if ((NegEdges[0] >= (MAX_LINE_SCAN - MAX_LINE_WIDTH)) && (LastLinePosError > 0))    // neg edge is within line width of edge of camera (RIGHT)
+    {
+       CurrentTrackStatus = LineFound;                                   // report line found!
+       UnknownCount = 0;                                                 // reset unknown status count
+       LastLinePosition = CurrentLinePosition;
+       CurrentLinePosition = NegEdges[0] + ( MAX_LINE_WIDTH / 2);        // update line position
+    //   TERMINAL_PRINTF("*** SINGLE NEGEDGE LINE FOUND AT POSITION %9.3f *** \r\n", CurrentLinePosition);
+    } 
+  } else if ((numPosEdges == 2) && (numNegEdges == 2))  {     // 2 negative and 2 positive edges found (STARTING/FINISH GATE)
+  
+    if ((((NegEdges[0] - PosEdges[0]) >= MIN_LINE_WIDTH) && ((NegEdges[0] - PosEdges[0]) <= MAX_LINE_WIDTH)) &&    // white left 'line'
+        (((NegEdges[1] - PosEdges[1]) >= MIN_LINE_WIDTH) && ((NegEdges[1] - PosEdges[1]) <= MAX_LINE_WIDTH)) &&    // white right 'line'
+        (((PosEdges[1] - NegEdges[0]) >= MIN_LINE_WIDTH) && ((PosEdges[1] - NegEdges[0]) <= MAX_LINE_WIDTH))       // actual track line
+        )
+           
+       
+    if (startRaceTicker > STARTGATEDELAY) {                      // only start counting for starting gate until after delay
+      StartGateFoundCount++;
+    }
+    
+    CurrentTrackStatus = StartGateFound;
+    UnknownCount = 0;                                            // reset unknown status count
+           
+  } else if ((numPosEdges > 1) && (numNegEdges > 1)) {   // more than 1 negative edge and positive edge found (but not 2 for both) (STARTING / FINISH GATE)
+  
+   // remove edges that aren't close to center TBD DDHH
+   
+      if (terminalOutput == 3) {
+         TERMINAL_PRINTF("***************************************** \r\n");
+         TERMINAL_PRINTF("********** NOT SURE FOUND ********** \r\n");
+         TERMINAL_PRINTF("***************************************** \r\n");
+       } 
+    CurrentTrackStatus = Unknown; 
+  
+  } else {  // no track or starting gate found
+  
+    if (terminalOutput == 3) {
+      TERMINAL_PRINTF("***************************************** \r\n");
+      TERMINAL_PRINTF("*** !!!!!!!!!! LINE NOT FOUND !!!!!!! *** \r\n", CurrentLinePosition);
+      TERMINAL_PRINTF("***************************************** \r\n");
+    }
+  
+    CurrentTrackStatus = Unknown;
+    UnknownCount++;
+  }
+  
+  
+
+
+}
+
+void ActOnTrackStatus()
+{
+  // Decide what to do next based on current track status
+
+  if (CurrentTrackStatus == LineFound)   {             // LINE FOUND!
+  
+    if (terminalOutput == 3) {
+      TERMINAL_PRINTF("***************************************** \r\n");
+      TERMINAL_PRINTF("*** LINE FOUND AT POSITION %9.3f *** \r\n", CurrentLinePosition);
+      TERMINAL_PRINTF("***************************************** \r\n");
+    }
+  
+    // Update steering position 
+    SteeringControl();
+
+    // Apply to servo    
+    Steer();
+    
+  } else if (CurrentTrackStatus == StartGateFound) {   // STARTING GATE FOUND
+  
+    if (terminalOutput == 3) {
+      TERMINAL_PRINTF("***************************************** \r\n");
+      TERMINAL_PRINTF("********** STARTING GATE FOUND ********** \r\n");
+      TERMINAL_PRINTF("**********     count = %d      ********** \r\n", StartGateFoundCount);
+      TERMINAL_PRINTF("***************************************** \r\n");
+    }
+    
+    // END RACE!
+    if (startGateStop) {
+      if (StartGateFoundCount > STARTGATEFOUNDMAX)
+      {
+       go = false;   // STOP!!
+      } 
+    }
+  
+  }
+  
+
+
+}
+
+void SteeringControl()
+{
+
+  float targetPosition = (float)( (NUM_LINE_SCAN / 2) - 0.5);  // target to achieve for line position
+
+  float KP;                                                    // proportional control factor
+  float KI;                                                    // integral control factor
+  float KD;                                                    // derivative control factor
+  
+  float Pout, Iout, Dout;                                      // PID terms
+  
+  // Calculate error
+  // make error to the right positive
+  // i.e. if LINE to the right-- then CurrentLinePosError > 0
+  //      if LINE to the left -- then CurrentLinePosError < 0
+  CurrentLinePosError = CurrentLinePosition - targetPosition;
+
+  // Get absolute error
+  if (CurrentLinePosError >= 0) 
+    AbsError = CurrentLinePosError;
+  else
+    AbsError = -1 * CurrentLinePosError;
+
+  // CHOOSE SET OF PID CONTROL PARAMETERS
+  switch (CONTROL_METHOD) {
+    case 0:
+      // Pure proportional control based on range of steering values vs. range of error values
+      KP = (float) ( MAX_STEER_RIGHT - MAX_STEER_LEFT ) / ( NUM_LINE_SCAN - (2*FILTER_ENDS) - MIN_LINE_WIDTH );
+      KD = 0;
+      KI = 0;
+      break;
+   case 1:
+      // Proportional control with 50% bit more oomph --- a bit more aggressive around the bends
+      KP = (float) ( MAX_STEER_RIGHT - MAX_STEER_LEFT ) / ( NUM_LINE_SCAN - (2*FILTER_ENDS) - MIN_LINE_WIDTH );
+      KP = KP * 1.5;
+      KD = 0;
+      KI = 0;
+      break;
+    case 2:  // MANUAL TUNING CASE 1 (use pot to help determine tuning parameters)
+      KP = TUNE_KP;
+      KI = TUNE_KI;
+      KD = TUNE_KD;
+    case 3:
+      if (AbsError < ABS_ERROR_THRESH) {
+        KP = 0.003;  // when relatively straight, keep KP gain low
+      } else {
+        KP = 0.010;  // when curve begins or off track, increase KP gain
+      }
+      KI = 0;
+      KD = 0;
+      
+    default:
+      break;
+  }
+  
+  /* Pseudocode
+   previous_error = 0
+   integral = 0 
+   start:
+     error = setpoint - measured_value
+     integral = integral + error*dt
+     derivative = (error - previous_error)/dt
+     output = Kp*error + Ki*integral + Kd*derivative
+     previous_error = error
+     wait(dt)
+     goto start 
+  */
+  
+  
+  if (terminalOutput == 3) {
+    TERMINAL_PRINTF("KP = %6.4f\r\n", KP);
+    TERMINAL_PRINTF("TARGET %6.3f\r\n", targetPosition);
+  }
+  
+
+
+    // Update integral of error
+    // i.e. if LINE stays to the right, then SumLinePosError increases
+    // i.e. if LINE stays to the left, then SumLinePosError decreases
+    SumLinePosError = SumLinePosError + ( CurrentLinePosError * DT );
+
+    DerivError = (CurrentLinePosError - LastLinePosError) / DT;
+    
+    if (terminalOutput == 3) {
+      TERMINAL_PRINTF("CURRENT LINE POSITION %9.3f\r\n", CurrentLinePosition);
+      TERMINAL_PRINTF("CURRENT LINE POSITION ERROR %9.3f\r\n", CurrentLinePosError);
+    }
+    
+    // SECOND- calculate new servo position
+    
+    // proportional control term
+    Pout = KP * CurrentLinePosError;
+
+    // integral control term
+    Iout = KI * SumLinePosError;
+
+    // Derivative control term
+    Dout = KD * DerivError;
+
+    if (terminalOutput == 3) {
+      TERMINAL_PRINTF("KP = %6.4f\r\n", KP);
+      TERMINAL_PRINTF("KI = %6.4f\r\n", KI);
+      TERMINAL_PRINTF("KD = %6.4f\r\n", KD);
+      TERMINAL_PRINTF("Pout = %6.4f\r\n", Pout);
+      TERMINAL_PRINTF("Iout = %6.4f\r\n", Iout);
+      TERMINAL_PRINTF("Dout = %6.4f\r\n", Dout);
+    }
+
+    // Finally add offset to steering to account for non-centered servo mounting
+    // CurrentSteerSetting = Pout + Iout + Dout + ( (float) (MAX_STEER_LEFT + MAX_STEER_RIGHT) / 2 );
+    CurrentSteerSetting = Pout + ( (float) (MAX_STEER_LEFT + MAX_STEER_RIGHT) / 2 );
+    
+    // store for next cycle deriv calculation
+    LastLinePosError = CurrentLinePosError;
+
+    // for tuning control algo only
+    if (1 == 0) {
+      TERMINAL_PRINTF("*** ******************************** \r\n");
+      TERMINAL_PRINTF("*** LINE FOUND AT POSITION %9.3f *** \r\n", CurrentLinePosition);
+      TERMINAL_PRINTF("*** ERROR %9.3f *** \r\n", CurrentLinePosError);
+      TERMINAL_PRINTF("*** INTEGRAL ERROR %9.3f *** \r\n", SumLinePosError);
+      TERMINAL_PRINTF("*** DERIVATIVE ERROR %9.3f *** \r\n", DerivError);
+      TERMINAL_PRINTF("*** P STEER SETTING %9.3f *** \r\n", CurrentSteerSetting);
+      TERMINAL_PRINTF("*** PI STEER SETTING  %9.3f *** \r\n", (CurrentSteerSetting + Iout));
+      TERMINAL_PRINTF("*** ******************************** \r\n");
+      wait_ms(1000);
+    }
+
+}
+
+void Steer()
+{
+
+    // make sure doesn't go beyond steering limits
+    if (CurrentSteerSetting > MAX_STEER_RIGHT)
+    { 
+       CurrentSteerSetting = MAX_STEER_RIGHT;
+    } else if (CurrentSteerSetting < MAX_STEER_LEFT)
+    {
+       CurrentSteerSetting = MAX_STEER_LEFT;
+    }
+
+    if (terminalOutput == 3) {
+      TERMINAL_PRINTF("APPLYING SERVO SETTING %5.3f\r\n", CurrentSteerSetting);
+    }
+    TFC_SetServo(0,CurrentSteerSetting);  
+
+}
+
+void SpeedControl()
+{
+
+  // Get max speed setting from reading pot0
+  // then adjust
+  
+  float ErrLimit;
+  float LeftDriveRatio, RightDriveRatio;
+  
+  // set maximum speed allowed
+  switch (1)
+    {
+      case 0:
+        // read value off pot0
+        MaxSpeed = TFC_ReadPot(0);
+        break;
+      case 1:
+        if (doRisky)
+          MaxSpeed = TUNE_SPEED + 0.1;
+        else 
+          MaxSpeed = TUNE_SPEED;
+        break;
+      case 2:
+        MaxSpeed = SUB_LIGHT_SPEED;
+        break;
+      case 3:
+        MaxSpeed = LIGHT_SPEED;
+        break;
+      case 4:
+        MaxSpeed = RIDICULOUS_SPEED;      
+        break;
+      case 5:
+        MaxSpeed = LUDICROUS_SPEED;      
+        break;        
+      default:
+        break;
+    }
+    
+  switch (SPEED_ADJUST)
+   {
+     case 0:
+       // SPEED ADJUST METHOD 0
+       // no speed adjust
+       LeftDriveRatio = MAX_POWER;
+       RightDriveRatio = LeftDriveRatio;
+     case 1:
+       // SPEED ADJUST METHOD 1
+       // High speed when error is low, low speed when error is high
+       // lower speed when more than third outside of center
+       ErrLimit = ((float) RANGE ) * 0.5 * ERR_RATIO * 0.33;
+       if (AbsError > ErrLimit) {
+         LeftDriveRatio = MIN_POWER;
+       } else {
+         LeftDriveRatio = MAX_POWER;
+       }
+       RightDriveRatio = LeftDriveRatio;
+       break;
+     case 2:
+       // SPEED ADJUST METHOD 2
+       // Have max/min speed adjust proportional to absolute value of line error
+       ErrLimit = ((float) RANGE )  * 0.5 * ERR_RATIO; 
+       LeftDriveRatio = MAX_POWER - ((MAX_POWER - MIN_POWER) * (AbsError / ErrLimit));
+       RightDriveRatio = LeftDriveRatio;
+       break;
+     case 3:
+       // SPEED ADJUST METHOD 3
+       // have wheel relative speed proportional to absolute value of line error
+       ErrLimit = ((float) RANGE )  * 0.5 * ERR_RATIO;
+       if (CurrentLinePosError > 0) {           // heading right
+         LeftDriveRatio = MAX_POWER;
+         RightDriveRatio = (MIN_POWER - MAX_POWER) * (CurrentLinePosError * 2 / ( (float) RANGE ) ) + MAX_POWER;
+       } else if (CurrentLinePosError < 0) {    // heading left
+         RightDriveRatio = MAX_POWER;
+         LeftDriveRatio = (MAX_POWER - MIN_POWER) * (CurrentLinePosError * 2 / ( (float) RANGE ) ) + MAX_POWER;
+       } else {
+         LeftDriveRatio = MAX_POWER;
+         RightDriveRatio = MAX_POWER;
+       }
+       break;
+     case 4:
+       // SPEED ADJUST METHOD 4
+       // have wheel relative speed proportional to absolute value of line error
+       // only when above a certain error
+       ErrLimit = ((float) RANGE )  * 0.5 * ERR_RATIO * 0.1;
+       if (CurrentLinePosError > ErrLimit) {           // heading right
+         LeftDriveRatio = MAX_POWER - (MAX_POWER - MIN_POWER) * (CurrentLinePosError * 2 / ( (float) RANGE ) );
+         RightDriveRatio = MIN_POWER;
+       } else if (CurrentLinePosError < (-1 * ErrLimit)) {    // heading left
+         RightDriveRatio = MAX_POWER - (MAX_POWER - MIN_POWER) * (CurrentLinePosError * 2 / ( (float) RANGE ) );
+         LeftDriveRatio = MIN_POWER;
+       } else {
+         LeftDriveRatio = MAX_POWER;
+         RightDriveRatio = MAX_POWER;
+       }
+       break; 
+     case 5:
+       // SPEED ADJUST METHOD 5
+       // High speed when error is low, low speed when error is high
+       // lower speed when more than third outside of center
+       ErrLimit = ((float) RANGE ) * 0.5 * ERR_RATIO * 0.2;
+       if (AbsError > ErrLimit) {
+         LeftDriveRatio = MIN_POWER;
+       } else {
+         LeftDriveRatio = MAX_POWER;
+       }
+       RightDriveRatio = LeftDriveRatio;
+       break;   
+     case 6:
+       // SPEED ADJUST METHOD 6
+       // High speed when error is low, low speed when error is high
+       // lower speed when more than third outside of center
+       if (AbsError > ABS_ERROR_THRESH) {
+         LeftDriveRatio = MIN_POWER;
+       } else {
+         LeftDriveRatio = MAX_POWER;
+       }
+       RightDriveRatio = LeftDriveRatio;
+       break;                 
+     default:
+       break;
+       
+  }
+  // TBD-- add speed adjust based on Xaccel sensor!
+
+
+  // currently no control mechanism as don't have speed sensor  
+  CurrentLeftDriveSetting = (float) (LeftDriveRatio / 100) * MaxSpeed;
+  CurrentRightDriveSetting = (float) (RightDriveRatio / 100) * MaxSpeed;
+
+  
+  if (terminalOutput == 3) {
+    TERMINAL_PRINTF("Abs Error: %4.2f\r\n", AbsError);
+    TERMINAL_PRINTF("Error Limit: %4.2f\r\n", ErrLimit);
+    TERMINAL_PRINTF("MAX SPEED = %5.2f\n", MaxSpeed);
+    TERMINAL_PRINTF("Current Left Drive Setting: %5.2f\r\n", CurrentLeftDriveSetting);
+    TERMINAL_PRINTF("Current Right Drive Setting: %5.2f\r\n", CurrentRightDriveSetting);
+  }
+  if (1 == 0) {
+   TERMINAL_PRINTF("Current Left Drive Setting: %5.2f\r\n", CurrentLeftDriveSetting);
+   TERMINAL_PRINTF("Current Right Drive Setting: %5.2f\r\n", CurrentRightDriveSetting);
+  }
+
+}
+
+void Drive()
+{
+
+  // START!
+  // if not going, go when button A is pressed
+  if (!go) {
+    if(TFC_PUSH_BUTTON_0_PRESSED) {
+      go = true;
+      UnknownCount = 0;
+      StartGateFoundCount = 0;
+      startRaceTicker = TFC_Ticker[0];  // keep track of start of race
+      logDataIndex = 0;                 // reset log data index
+    }
+  }
+  
+  // STOP!
+  // if going, stop when button A is pressed
+  if (go) {              
+   if(TFC_PUSH_BUTTON_1_PRESSED) {
+      go = false;
+      StartGateFoundCount = 0;
+    }
+  }
+
+  // EMERGENCY STOP!
+  // 'kill switch' to prevent crashes off-track
+  if (killSwitch) {
+    if (UnknownCount > UNKNOWN_COUNT_MAX) {  // if track not found after certain time
+      go = false;                            // kill engine
+      StartGateFoundCount = 0;
+    }
+  }
+
+// ****************
+  
+  if (!go) { // stop!
+    TFC_SetMotorPWM(0,0); //Make sure motors are off 
+    TFC_HBRIDGE_DISABLE;
+  }
+
+  if (go) {  // go!
+    TFC_HBRIDGE_ENABLE;
+    // motor A = right, motor B = left based on way it is mounted
+    TFC_SetMotorPWM(CurrentRightDriveSetting,CurrentLeftDriveSetting);
+  }
+}
+
+
+void adjustLights()
+{
+
+  // LIGHT ADJUST METHOD 1
+  // threshold is 1/5 of light intensity 'range'
+  if (1 == 0) {
+    DerivThreshold = (float) (MaxLightIntensity - MinLightIntensity) / 5;
+    NegDerivThreshold = (float) -1 * (DerivThreshold);
+    PosDerivThreshold = (float) (DerivThreshold);
+  } else {
+  // LIGHT ADJUST METHOD 2 -- SEEMS TO WORK MUCH BETTER
+  // pos edge threshold is half range of max deriv above aver derive
+  // neg edge threshold is half range of min deriv above aver derive
+   
+    NegDerivThreshold = (float) (minDerVal - aveDerVal) * DER_RATIO;
+    PosDerivThreshold = (float) (maxDerVal - aveDerVal) * DER_RATIO;
+  
+  }
+
+  printAdjustLightsData();
+
+}
+
+void printAdjustLightsData()
+{
+  if (terminalOutput == 3) {
+    TERMINAL_PRINTF("Max Light Intensity: %4d\r\n", MaxLightIntensity);
+    TERMINAL_PRINTF("Min Light Intensity: %4d\r\n", MinLightIntensity);
+    TERMINAL_PRINTF("Deriv Threshold: %9.3f\r\n", DerivThreshold);
+  }
+
+}
+
+void feedbackLights()
+{
+   switch (CurrentTrackStatus)
+   {
+     case LineFound:
+       TFC_BAT_LED0_OFF;
+       TFC_BAT_LED1_ON;     
+       TFC_BAT_LED2_ON;
+       TFC_BAT_LED3_OFF;
+       break;
+     case StartGateFound:
+       TFC_BAT_LED0_ON;
+       TFC_BAT_LED1_OFF;     
+       TFC_BAT_LED2_OFF;
+       TFC_BAT_LED3_ON;   
+       break;
+     default:
+       TFC_BAT_LED0_OFF;
+       TFC_BAT_LED1_OFF;     
+       TFC_BAT_LED2_OFF;
+       TFC_BAT_LED3_OFF;
+   }
+    
+}
+
diff -r 000000000000 -r 98e98e01a6ce Spices/Spices.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Spices/Spices.h	Sun Apr 20 03:33:03 2014 +0000
@@ -0,0 +1,133 @@
+#include "mbed.h"
+
+#ifndef _SPICES_H
+#define _SPICES_H
+
+// *******************************************
+// MASTER CONTROL PROGRAM
+
+// Loop at Servo cycle (currently 50Hz / 20mS)
+// Camera gets updated at its own period
+//   (currently 50Hz / 20mS)
+// 
+//   REQUIREMENTS:
+//   - Control servos in response to track line position
+//   - Gather as much camera data as possible between
+//     servo update cycles to get best read on the line
+//     (currently 1:1 though @ 50Hz)
+//   - Ignore erronous signals:
+//       - "mud" on track
+//       - low contrast light situations
+//       - track crossing itself (all black situation)
+//   - Detects 'starting line' -- ignores first detect (START)
+//     and stops after second detect (FINISH)
+//
+//   INPUTS:
+//   - linescancamera data (0-127)
+//   - maximum speed
+//   - filter settings:
+//       A = 15 (number of pixels at each end to ignore)
+//       B = 20 (estimated width of line)(possible issue if line far away)
+//       C = 2^12 (max value based on ADC sample rate of 12 bits)
+//       D = Edge threshold of Derivative (max / 4 = 2^10)
+//   - control parameters, KP and KD
+//
+//   CONTROL ALGORITHM:
+//   1 - Get Line Position
+//   2 - Compute Error from Line Position
+//   3 - Set Servo position based on Error and Derivative of Error
+//   4 - Store error for next cycle to perform derivative
+//   
+//
+//   GET LINE POSITION
+//     INPUTS: linescan data
+//     RETURNS: either position or starting gate flag
+//   ALGO:
+//   - Find line edges:
+//      - filter out first and last A number of pixels from left and right
+//      - calculate derivative of data
+//      - search for line edges in derivative data (search for either track line or starting gate)
+//        - Search for all pixels with Value < -D, indicating negative edge (large negative means going from white to black)
+//        - Search for all pixels with Value > D, indicating positive edge (large positive means going from black to white)
+//        - Clean up adjacent line edges-- edges 1 pixel away from each other combined to be considered a single edge, average pixel value
+//   - if starting gate then send up flag
+//   - if track, calculate position
+//
+//
+//   COMPUTE LINE ERROR
+//   - take line position and target-- calculate error (negative or positive)
+//
+//   SET SERVO POSITION 
+//      -  int servoPosition = KP * Error + KD * (Error - lastError);
+//      -  lastError = Error;
+//
+//
+//   TBD:
+//   - store multiple edge positions in order to average prior to next servo update
+//
+// *******************************************
+//
+void MasterControlProgram();
+
+
+// prints out line scan data for you
+void printLineScanData(uint16_t *LineScanData);
+
+// calculates derivative of line scan data
+void derivativeLineScan(uint16_t* LineScanDataIn, float* DerivLineScanDataOut);
+
+// prints out derivative of line scan data -- assumes deriv already calculated
+void printDerivLineScanData(float* derivLineScanData);
+
+// serves to grab a frame of camera data
+void grabCameraFrame();
+
+// find negative and positive edges in image data, store in array, combines edges found in adjacent pixels
+void findEdges(float* derivLineScanData);
+
+// improved algo to find negative and positive edges in image data, store in array, combines edges found in adjacent pixels
+void findEdges_v2(float* derivLineScanData);
+
+// prints out edge data found
+void printEdgesFound();
+
+// review edge data
+//   - report line position if there
+//   - set starting gate flag if there
+//   - do nothing with position value otherwise
+void reviewEdges();
+
+// Decide new actions based on track status
+void ActOnTrackStatus();
+
+// Update Steering settings
+void SteeringControl();
+
+// Apply steering setting to servo!
+void Steer();
+
+// Update speed settings
+void SpeedControl();
+
+// Apply speed settings to motors!
+void Drive();
+
+// Adjust parameters based on max light measured value
+void adjustLights();
+
+// print out light adjust data
+void printAdjustLightsData();
+
+// Give user feedback as to detection state via LEDs
+void feedbackLights();
+
+// read DIP switches and potentiometers for setting changes
+void readSwitches();
+     
+// capture log data
+void captureData();
+
+// dump log data to terminal
+void dumpData();
+           
+#endif
diff -r 000000000000 -r 98e98e01a6ce common.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common.cpp	Sun Apr 20 03:33:03 2014 +0000
@@ -0,0 +1,9 @@
+#include "mbed.h"
+
+#include "common.h"
+
+Serial PC(USBTX,USBRX); 
+
+Ticker TFC_TickerObj;
+
+volatile uint32_t TFC_Ticker[NUM_TFC_TICKERS];
\ No newline at end of file
diff -r 000000000000 -r 98e98e01a6ce common.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common.h	Sun Apr 20 03:33:03 2014 +0000
@@ -0,0 +1,22 @@
+#include "mbed.h"
+
+#ifndef _COMMON_H
+#define _COMMON_H
+
+//This macro is to maintain compatibility with Codewarrior version of the sample.   This version uses the MBED libraries for serial port access
+extern Serial PC;
+
+#define TERMINAL_PRINTF     PC.printf
+
+ 
+ //This ticker code is used to maintain compability with the Codewarrior version of the sample.   This code uses an MBED Ticker for background timing.
+ 
+#define NUM_TFC_TICKERS 4
+
+extern Ticker TFC_TickerObj;
+ 
+
+extern volatile uint32_t TFC_Ticker[NUM_TFC_TICKERS];
+
+
+#endif
\ No newline at end of file
diff -r 000000000000 -r 98e98e01a6ce main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Apr 20 03:33:03 2014 +0000
@@ -0,0 +1,200 @@
+#include "mbed.h"
+#include "TFC.h"
+
+#include "common.h"
+#include "Spices.h"
+
+
+void TFC_TickerUpdate()
+{
+    int i;
+ 
+    for(i=0; i<NUM_TFC_TICKERS; i++)
+     {
+        if(TFC_Ticker[i]<0xFFFFFFFF) 
+        {
+            TFC_Ticker[i]++;
+        }
+    }
+}
+
+void DemoProgram()
+{
+  uint32_t i,j,t = 0;
+  float ReadPot0, ReadPot1;
+
+
+  //This Demo program will look at the middle 2 switch to select one of 4 demo modes.
+  //Let's look at the middle 2 switches
+  switch((TFC_GetDIP_Switch()>>1)&0x03)
+  {
+  default:
+  case 0 :
+      //Demo mode 0 just tests the switches and LED's
+      if(TFC_PUSH_BUTTON_0_PRESSED)
+          TFC_BAT_LED0_ON;
+      else
+          TFC_BAT_LED0_OFF;
+      
+      if(TFC_PUSH_BUTTON_1_PRESSED)
+          TFC_BAT_LED3_ON;
+      else
+          TFC_BAT_LED3_OFF;
+      
+      
+/*      if(TFC_GetDIP_Switch()&0x01)
+          TFC_BAT_LED1_ON;
+      else
+          TFC_BAT_LED1_OFF;
+      
+      if(TFC_GetDIP_Switch()&0x08)
+          TFC_BAT_LED2_ON;
+      else
+          TFC_BAT_LED2_OFF; */
+      
+      break;
+          
+  case 1:
+     TFC_HBRIDGE_DISABLE;
+                    
+     // if (TFC_HBRIDGE_ENABLED) {
+        
+    //    TFC_HBRIDGE_ENABLED = false;
+    //  }
+
+      //Demo mode 1 will just move the servos with the on-board potentiometers
+      if(TFC_Ticker[0]>=20) // every 40mS...
+      {
+          TFC_Ticker[0] = 0; //reset the Ticker
+          //update the Servos
+          ReadPot0 = TFC_ReadPot(0);
+          ReadPot1 = TFC_ReadPot(1);
+          TFC_SetServo(0,ReadPot0);
+          TFC_SetServo(1,ReadPot1);
+          TERMINAL_PRINTF("Pot0 = %1.2f\r\n", ReadPot0);
+      //    TERMINAL_PRINTF("Pot1 = %1.2f\r\n", ReadPot1);
+      }
+      //Let's put a pattern on the LEDs
+      if(TFC_Ticker[1] >= 125) // every 250mS... cycle through LEDs
+      {
+          TFC_Ticker[1] = 0;
+          t++;
+          if(t>4)
+          {
+              t=0;
+          }           
+          TFC_SetBatteryLED_Level(t);
+      }
+      
+      TFC_SetMotorPWM(0,0); //Make sure motors are off 
+      TFC_HBRIDGE_DISABLE;
+
+      break;
+      
+  case 2 :
+      TFC_HBRIDGE_ENABLE;
+     
+      ReadPot0 = TFC_ReadPot(0);
+      ReadPot1 = TFC_ReadPot(1);
+ //     TERMINAL_PRINTF("Pot0 = %1.2f\n", ReadPot0);
+ //     TERMINAL_PRINTF("Pot1 = %1.2f\n", ReadPot1);
+      TFC_SetMotorPWM(ReadPot0,ReadPot1);
+              
+      //Let's put a pattern on the LEDs
+      if(TFC_Ticker[1] >= 125)
+          {
+              TFC_Ticker[1] = 0;
+                  t++;
+                  if(t>4)
+                  {
+                      t=0;
+                  }           
+              TFC_SetBatteryLED_Level(t);
+          }
+      break;
+  
+  case 3 :
+      //Demo Mode 3 will be in Freescale Garage Mode.  It will beam data from the Camera to the 
+      //Labview Application
+      //note that there are some issues 
+      if(TFC_Ticker[0]>1000 && TFC_LineScanImageReady>0) // every 2s ...
+          {
+           TFC_Ticker[0] = 0;
+           TFC_LineScanImageReady=0; // must reset to 0 after detecting non-zero
+          
+              if(t==0)
+                  t=4;
+              else
+                  t--;
+              
+               TFC_SetBatteryLED_Level(t);
+              
+               for(i=0;i<8;i++) // print one line worth of data (128) from Camera 0
+               {
+                  for(j=0;j<16;j++)
+                  {
+                       
+                       TERMINAL_PRINTF("0x%X",TFC_LineScanImage0[(i*16)+j]);
+                      
+                       if((i==7) && (j==15))  // when last data reached put in line return
+                           TERMINAL_PRINTF("\r\n",TFC_LineScanImage0[(i*16)+j]);
+                       else
+                           TERMINAL_PRINTF(",",TFC_LineScanImage0[(i*16)+j]);
+                      
+                  }
+                  wait_ms(10);
+               }
+              
+     /*          for(i=0;i<8;i++) // print one line worth of data (128) from Camera 1 ??
+               {
+                    for(j=0;j<16;j++)
+                     {
+                       TERMINAL_PRINTF("0x%X",TFC_LineScanImage1[(i*16)+j]);
+                      
+                       if((i==7) && (j==15))  // when last data reached put in line return
+                           TERMINAL_PRINTF("\r\n",TFC_LineScanImage1[(i*16)+j]);
+                       else
+                           TERMINAL_PRINTF(",",TFC_LineScanImage1[(i*16)+j]);
+                      }   
+                      
+                      wait_ms(10);  
+              }      */                                 
+                  
+          }
+          
+
+
+      break;
+  } // end case
+
+}
+
+ 
+int main()
+{
+    // TERMINAL TYPE  
+    PC.baud(115200); // works with Excel and TeraTerm 
+    //PC.baud(9600); // works with USB Serial Monitor Lite: https://play.google.com/store/apps/details?id=jp.ksksue.app.terminal; doesn't work > 9600
+    TFC_TickerObj.attach_us(&TFC_TickerUpdate,2000); // update ticker array every 2mS (2000 uS)
+   
+    TFC_Init();
+    
+    for(;;)
+    {      
+        //TFC_Task must be called in your main loop.  This keeps certain processing happy (I.E. Serial port queue check)
+        //   TFC_Task();
+
+
+        // If DIP switch 1 is high, then run MCP, else Demo program
+        if(TFC_GetDIP_Switch()&0x01)
+          // Run MCP
+          MasterControlProgram();
+        else      
+          // Run Demo Program
+          DemoProgram();
+ 
+    } // end of infinite for loop
+    
+ 
+}
+