Prana Koirala / Mbed 2 deprecated Wifi_controlled_Robot_ECE4180_Lab4

Wifi Controlled Robot is done as a mini project (Lab4) for ECE 4180 class (Georgia Tech). Robot is assembled in Sparkfun's Shadow chasis robot kit. This robot takes the command from the webpage to move forward, reverse without colliding. The distance sensor is used as a mechanism for collision detection and play a short beep sound. It turn 90 degree with magnetometer when the turn command is sent.

Dependencies:   Motordriver mbed

/media/uploads/pkoirala3/capture.jpg Showing the setup and calibration: Part1 In this part the Wifi setups and attains an IP address so we can control it through a webpage on our phone/PC. After it obtains an IP address it calibrates the IMU so we can have accurate compass headings for precise turns.

The parts that we use are as follows:

  • Mbed
  • 2 DC motors
  • H-Bridge (to drive the DC motors)
  • Speaker
  • Class D Amp (to drive the Speaker)
  • IMU (use the magnometer for compass headings)
  • Wifi card (ESP8266)

Showing webpage functionality and Robot Functionality: In this part we demonstrate the functionality of the robot and the webpage to control it.

Final Code

[Repository '/teams/Prana-Koirala/code/Wifi_controlled_Robot_ECE4180/docs/tip/main_8cpp_source.html' not found]

Files at this revision

API Documentation at this revision

Revision 5:e9f1030a5bbb, committed 2017-03-13

Comitter:
pkoirala3
Date:
Mon Mar 13 21:54:22 2017 +0000
Parent:
4:166570fa7fda
Commit message:
ECE4180_ROBOT_CONTROLLEDBY_WiFI

Changed in this revision

Speaker.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 166570fa7fda -r e9f1030a5bbb Speaker.h
--- a/Speaker.h	Mon Mar 13 17:53:47 2017 +0000
+++ b/Speaker.h	Mon Mar 13 21:54:22 2017 +0000
@@ -1,19 +1,52 @@
-#include "mbed.h"
-// a new class to play a note on Speaker based on PwmOut class
 class Speaker
 {
 public:
     Speaker(PinName pin) : _pin(pin) {
 // _pin(pin) means pass pin to the Speaker Constructor
+// precompute 32 sample points on one sine wave cycle
+// used for continuous sine wave output later
+        for(int k=0; k<32; k++) {
+            Analog_out_data[k] = int (65536.0 * ((1.0 + sin((float(k)/32.0*6.28318530717959)))/2.0));
+            // scale the sine wave to 16-bits - as needed for AnalogOut write_u16 arg
+        }
+
     }
-// class method to play a note based on PwmOut class
+// class method to play a note based on AnalogOut class
     void PlayNote(float frequency, float duration, float volume) {
-        _pin.period(1.0/frequency);
-        _pin = volume/2.0;
+        // scale samples using current volume level arg
+        for(int k=0; k<32; k++) {
+            Analog_scaled_data[k] = Analog_out_data[k] * volume;
+        }
+        // reset to start of sample array
+        i=0;
+        // turn on timer interrupts to start sine wave output
+        Sample_Period.attach(this, &Speaker::Sample_timer_interrupt, 1.0/(frequency*32.0));
+        // play note for specified time
         wait(duration);
-        _pin = 0.0;
+        // turns off timer interrupts
+        Sample_Period.detach();
+        // sets output to mid range - analog zero
+        this->_pin.write_u16(32768);
+
     }
+private:
+// sets up specified pin for analog using AnalogOut class
+    AnalogOut _pin;
+    // set up a timer to be used for sample rate interrupts
+    Ticker Sample_Period;
 
-private:
-    PwmOut _pin;
-};
\ No newline at end of file
+    //variables used by interrupt routine and PlayNote
+    volatile int i;
+    short unsigned Analog_out_data[32];
+    short unsigned Analog_scaled_data[32];
+
+// Interrupt routine
+// used to output next analog sample whenever a timer interrupt occurs
+    void Sample_timer_interrupt(void) {
+        // send next analog sample out to D to A
+        this->_pin.write_u16(Analog_scaled_data[i]);
+        // increment pointer and wrap around back to 0 at 32
+        i = (i+1) & 0x01F;
+    }
+};
+

diff -r 166570fa7fda -r e9f1030a5bbb main.cpp
--- a/main.cpp	Mon Mar 13 17:53:47 2017 +0000
+++ b/main.cpp	Mon Mar 13 21:54:22 2017 +0000
@@ -8,15 +8,15 @@
 DigitalOut  ledFwd(p8);
 DigitalOut  ledRev(p11);
 
-Motor A(p26, p16, p25, 1); // pwm, fwd, rev, can brake
+Motor A(p26, p16, p15, 1); // pwm, fwd, rev, can brake
 Motor B(p21, p22, p23, 1); // pwm, fwd, rev, can brake
 
 Serial pc(USBTX, USBRX);
 Serial esp(p28, p27); // tx, rx
 
-Speaker mySpeaker(p24);
+Speaker mySpeaker(p18);
 
-// LSM9DS1 IMU(p9, p10, 0xD6, 0x3C);
+LSM9DS1 IMU(p9, p10, 0xD6, 0x3C);
 
 AnalogIn DistSensorFwd(p19);
 AnalogIn DistSensorRev(p20);
@@ -43,13 +43,15 @@
 char webbuff[4096];
 char stateBuff[50];
 void SendCMD(),getreply(),ReadWebData(),startserver();
-void ImuCheck(), ObjDetect(float);
+void ImuCheckLeft(), ImuCheckRight(), ObjDetect(float);
+float calcHeading(float, float, float);
 char rx_line[1024];
 int port = 80;  // set server port
 int SERVtimeout = 5;    // set server timeout in seconds in case link breaks.
 
 int main()
-{   
+{
+    mySpeaker.PlayNote(500.0,0.5,1.0);
     pc.baud(9600);
     esp.baud(9600);
     esp.attach(&Rx_interrupt, Serial::RxIrq); //serial interrupt to receive data
@@ -57,16 +59,16 @@
     startserver();
     wait(0.01);
     DataRX=0;
-
-// Initially stop the robot 
+    mySpeaker.PlayNote(500.0,0.5,1.0);
+// Initially stop the robot
     A.stop(0.0);
     B.stop(0.0);
-/*
+
     IMU.begin();
     IMU.calibrate(1);
     IMU.calibrateMag(0);
     pc.printf("Final Calibration done, Ready to move...\r\n");
-*/
+
     while(1) {
         if(DataRX==1) {
             ReadWebData();
@@ -78,8 +80,8 @@
         char temp_buff[50];
         if(abs(stateA) > 1  && abs(stateB) > 1) strcpy(temp_buff, "Robot Stopped!");
         else if((stateA > 0 && stateA <= 1)&&(stateB > 0 && stateB <= 1)) { // obstacle within 10 cm and robot is still moving
-            // float Dist = DistSensorFwd;
-            // ObjDetect(Dist);
+            float Dist = DistSensorFwd;
+            ObjDetect(Dist);
             strcpy(temp_buff, "Robot Moving Forward!");
         } else if((stateA < 0 && stateA >= -1)&&(stateB < 0 && stateB >= -1)) { // If moving rev
             float Dist = DistSensorRev;
@@ -136,18 +138,18 @@
         ledRev = 0;
     }
     if( strstr(webdata, "select=BotLeft") != NULL ) {
-        A.speed(0.5);
-        B.stop(-0.5);
-        // ImuCheck();
-        wait(1.0);
+        A.speed(0.6);
+        B.stop(-0.6);
+        ImuCheckLeft();
+        // wait(1.0);
         A.stop(0.0);
         B.stop(0.0);
     }
     if( strstr(webdata, "select=BotRight") != NULL ) {
-        A.speed(-0.5);
-        B.speed(0.5);
-        // ImuCheck();
-        wait(1.0);
+        A.speed(-0.6);
+        B.speed(0.6);
+        ImuCheckRight();
+        // wait(1.0);
         A.stop(0.0);
         B.stop(0.0);
     }
@@ -388,40 +390,57 @@
     return;
 }
 
-/*
-// To make Robot Turn approximately 90 degree using IMU mag
-void ImuCheck()
+void ImuCheckRight()
 {
-    bool rotFlag = true;
-    IMU.readMag();
-    float initial_heading;
-    float mx = -1*IMU.mx;
-    float my = IMU.my;
-    if(my == 0.0) initial_heading = (mx < 0.0) ? 180.0 : 0.0;
-    else initial_heading = atan2(mx,my)*360.0/(2.0*PI);
-    initial_heading -= DECLINATION;
-    if(initial_heading>180.0) initial_heading = initial_heading - 360.0;
-    else if(initial_heading<0) initial_heading += 360.0;
-
-    while(rotFlag) {
+    float headingStart = calcHeading(IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my),IMU.calcMag(IMU.mz));
+    float newHeading = headingStart + 90.0;
+    //pc.printf("Start Heading: %f degress\n\r",headingStart);
+    //pc.printf("New Heading  : %f degress\n\r",newHeading);
+    float heading = calcHeading(IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my),IMU.calcMag(IMU.mz));
+    while (newHeading > heading) {
         IMU.readMag();
-        float mx = -1*IMU.mx;
-        float my = IMU.my;
-        float heading;
-        if (my == 0.0) heading = (mx < 0.0) ? 180.0 : 0.0;
-        else heading = atan2(mx, my)*360.0/(2.0*PI);
-        heading -= DECLINATION; //correct for geo location
-        if(heading>180.0) heading = heading - 360.0;
-        else if(heading<0.0) heading += 360.0;
-        if(abs(heading - initial_heading) > 90) rotFlag = 1;
+        heading = calcHeading(IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my),IMU.calcMag(IMU.mz));
+        if (heading < headingStart-5.0) heading = heading + 360.0;
+        //pc.printf("Magnetic Heading: %f degress\n\r",heading);
+        wait(0.1);
     }
 }
-*/
+
+
+void ImuCheckLeft()
+{
+    float headingStart = calcHeading(IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my),IMU.calcMag(IMU.mz));
+    float newHeading = headingStart - 90.0;
+    //pc.printf("Start Heading: %f degress\n\r",headingStart);
+    //pc.printf("New Heading  : %f degress\n\r",newHeading);
+    float heading = calcHeading(IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my),IMU.calcMag(IMU.mz));
+    while (newHeading < heading) {
+        IMU.readMag();
+        heading = calcHeading(IMU.calcMag(IMU.mx),IMU.calcMag(IMU.my),IMU.calcMag(IMU.mz));
+        if (heading > headingStart + 5.0) heading = heading - 360.0;
+        //pc.printf("Magnetic Heading: %f degress\n\r",heading);
+        wait(0.1);
+    }
+}
+
+float calcHeading(float mx, float my, float mz)
+{
+    mx = -mx;
+    float heading;
+    if (my == 0.0)
+        heading = (mx < 0.0) ? 180.0 : 0.0;
+    else
+        heading = atan2(mx, my)*360.0/(2.0*PI);
+    heading -= DECLINATION; //correct for geo location
+    if(heading>360.0) heading = heading - 360.0;
+    else if(heading<0.0) heading = 360.0  + heading;
+    return heading;
+}
 
 // Checking for obstacles in the way while moving Fwd and Rev
 void ObjDetect(float currDist)
 {
-    if(currDist > 0.98f) { // 1.0=4 cm, 0.0=30 cm
+    if(currDist > 0.9f) { // 1.0=4 cm, 0.0=30 cm
         myleds = 1;
         pc.printf("Obj detected at: %f cm\r\n",(1-currDist)*26+4);
         wait(0.001);
@@ -430,6 +449,7 @@
         ledFwd = 0;
         ledRev = 0;
         mySpeaker.PlayNote(500.0,0.5,0.5);
+        wait(1.0);
         myleds = 0;
     }
 }
\ No newline at end of file