Diff: main.cpp

Revision:

3:30dcfcf9412c

Parent:

2:8ae58834937f

Child:

4:9ee3ae61db7f

diff -r 8ae58834937f -r 30dcfcf9412c main.cpp
--- a/main.cpp	Mon Mar 10 23:33:38 2014 +0000
+++ b/main.cpp	Thu Apr 03 20:30:18 2014 +0000
@@ -1,18 +1,26 @@
 #include "mbed.h"
 #include "FIR_f32.h"
 #include "arm_math.h"
+#include "display.h"
 #define f_sampling 2000 //the sampling frequency
 #define NumTaps 27      //the number of FIR coefficients
-#define BlockSize 1024  //the size of the buffer
+#define BlockSize 2048  //the size of the buffer
+
+SPI spi(p5, p6, p7);
+DigitalOut cs(p8);
+ST7735_LCD disp( p14, p13, p12, p10, p11); //for digital display
+display lcd(&disp);
 
 Serial pc(USBTX, USBRX); //USB serial for PC, to be removed later
 AnalogIn input(p15); //pin 15 for analog reading
+AnalogOut waveOut(p18);
 float32_t waveform[BlockSize]; //array of input data
 float32_t postFilterData[BlockSize]; //array of filtered data
 bool fullRead; //whether the MBED has finish
 bool waitForNext;
 
 //the filter coefficients for a band pass filter, consider changing to doubles if not precise enough
+
 float32_t pCoeffs[NumTaps] = 
                 {    0.012000000000000,   0.012462263166161,  -0.019562318415964,  -0.026175892863747,
                      0.031654803781611,   0.050648026372209,  -0.032547136829180,  -0.070997780956819,
@@ -21,6 +29,29 @@
                     -0.020568171368382,   0.094643188024728,   0.032992306874351,  -0.070997780956815,
                     -0.032547136829177,   0.050648026372211,   0.031654803781612,  -0.026175892863746,
                     -0.019562318415964,   0.012462263166161,   0.012000000000000                        };
+//                    */
+/*
+float32_t pCoeffs[NumTaps] = 
+{
+    -0.00130297171184699,    -0.00456436168827987,    -0.00757978930408609,    -0.00696944302000657,
+        -0.00100059082174453,    0.00812867271498616, 0.0148953048520266,  0.0137935053264369,
+          0.00350484996910501, -0.0112195199182290, -0.0216305356563913, -0.0202538386423356,
+           -0.00609419278464673,    0.0137348990478646,  0.0275645559768492,  0.0261107576153156,
+             0.00866220574766616, -0.0156131009924596, -0.0324957126350438, -0.0311514181527343,
+              -0.0110879396617141, 0.0168179120126559,  0.0362758644669149,  0.0352058948414930,
+               0.0132978095684398,  -0.0172706692984796, -0.0386711719606551, -0.0379507530937637,
+                -0.0149419841919419, 0.0172996706397712,  0.0400000000000000,  0.0397279151377323,
+                  0.0164353142069562,  -0.0164055618588934, -0.0396949785867063, -0.0399629114640568,
+                   -0.0172605211576678, 0.0149790280104299,  0.0379815311949588,  0.0386933807609119,
+                     0.0172844840085185,  -0.0132904115318555, -0.0352024033389307, -0.0362742608690452,
+                      -0.0168170401765007, 0.0110885383139611,  0.0311518509994083,  0.0324959946809230,
+                        0.0156132578212073,  -0.00866213238945794,    -0.0261107291487171, -0.0275645472357883,
+                         -0.0137348973043660, 0.00609419268963993, 0.0202538383407381,  0.0216305354798053,
+                           0.0112195198475825,  -0.00350484999121515,    -0.0137935053321021, -0.0148953048532365,
+                            -0.00812867271519995,    0.00100059082171422, 0.00696944302000319, 0.00757978930408577,
+                             0.00456436168827984, 0.00130297171184699
+    };
+    //*/
 float32_t pState[NumTaps + BlockSize - 1];
 
                     
@@ -49,6 +80,46 @@
     }
     sampler.detach();
 }
+
+void outputWaveform()
+{
+    Ticker outputter;
+    waitForNext = true;
+    outputter.attach_us(&readPoint, (int) (1000000/f_sampling) ); //output data according the sampling freq
+    for (int i = 0; i < BlockSize; i++)
+    {
+        while (waitForNext); //wait until the ticker calls for the next data point
+        waveOut.write(postFilterData[i]);
+        waitForNext = true;
+    }
+    outputter.detach();
+}
+    
+int setPot(int wiperNo, float kOhms)
+{
+    //257 steps (8 bits + 1), see section 7.0 for SPI instructions
+    float Rmax = 100000;
+    spi.frequency(2000000);
+    spi.format(16, 0); //16 bits, mode b00
+    float ratio = kOhms * 1000.0 / Rmax;
+    if (ratio > 1) ratio = 1;
+    if (ratio < 0) ratio = 0;
+    int dataBits = (int) (ratio * 0x100);
+    int command = wiperNo << 12; //setting the Address and Command bits
+    command += dataBits; //add in the digital setting
+    spi.write(command);    
+    return command;
+}
+
+float32_t rms()
+{
+    float32_t rms = 0;
+    for(int i = 0; i < BlockSize; i++)
+    {
+        rms += postFilterData[i]*postFilterData[i];
+    }
+    return sqrt(rms/BlockSize);
+}
     
 
 int main() {
@@ -69,6 +140,9 @@
     int state = 0;
     uint16_t numTaps = NumTaps;
     uint32_t blockSize = BlockSize;
+    char buffer[32]; //for debugging scanf things
+    char* outputString;
+    float32_t estimate = 0;
     while(1) 
     {
         //pc.printf("While loop\n\r");
@@ -79,7 +153,7 @@
             //pc.printf("pre-filter init\n\r");
             arm_fir_init_f32(filter, numTaps, pCoeffs, pState, blockSize);
             //pc.printf("Pre-attachment");
-            
+            spi.frequency(1000000);
             state = 1;
             pc.printf("Done with init.\n\r");
             break;
@@ -87,10 +161,10 @@
         case 1: //read data, take samples
             pc.printf("Reading data.\n\r");
             readSamples();
-            state = 2;
+            state = 3;
             break;
             
-        case 2: //printout to pc connection
+        case 2: //printout to pc connection or other output debugging
             //pc.printf("into print\n\r");
             /*
             for (int i = 0; i < BlockSize; i++)
@@ -98,25 +172,66 @@
                 pc.printf("Waveform contents:%f\n\r", waveform[i]);
             }
             */
-            state = 3;
+            for (int i = 0; i < 10; i++) outputWaveform();
+            wait_ms(500);
+            state = 1;
             break;
         case 3: //filter?
             pc.printf("Filtering?\n\r");
             arm_fir_f32(filter, waveform, postFilterData, blockSize);
-            state = 6;
+            state = 2;
             break;
         case 4: //FFT?
             break;
         case 5: //output, write to display and PWM tone
+            sprintf(outputString, "RMS = %f", estimate);
+            lcd.print(outputString);
+            state = 1;
             break;
-        case 6: //calculate the average voltage
+        case 6: //calculate the average voltage maybe depreciated
+            /*
+            *   
+            *
+            
             double sum = 0;
             for (int i = 0; i < BlockSize; i++) sum += postFilterData[i];
             double average = sum/BlockSize*3.3;  //*3.3 V_ref (array stored as fractions of V_ref)
             pc.printf("Average = %f\n\r", average);
             wait_ms(500);
+            state = 2;
+            */
+            estimate = rms();
+            pc.printf("RMS = %f", estimate);
+            state = 5;
+            break;
+        case 7: //estimate amplitude
+            pc.printf("Into estimation\n\r");
+            int peaks = 0;
+            float sum = 0.0;
+            float prev, current, next;
+            for (int i = 0+1; i < BlockSize-1; i++)
+            {
+                prev = postFilterData[i-1];
+                current = postFilterData[i];
+                next = postFilterData[i+1];
+                if (prev < current && next < current) //local max
+                {
+                    sum += current;
+                    peaks++;
+                }
+            }
+            float average = sum/peaks;
+            pc.printf("Average of peaks (scalar) = %f\n\r", average);
             state = 1;
             break;
+            
+        case 8: //digital pot interfacing and calibration
+            pc.printf("kOhms?\n\r");
+            pc.scanf("%s", buffer);
+            float value = atof(buffer);
+            pc.printf("Command: %x Scanned:%f\n\r", setPot(0, value), value);
+            wait_ms(250);
+            break;
         default:
             break;
         }