Updated PID demo

demos/STM32/RT-STM32F303-DISCOVERY-PID/main.c

@@ -17,13 +17,14 @@
 #include "ch.h"
 #include "hal.h"
 #include "pid.h"
+#include <stdlib.h>
 
-pid_t pid;
+#define STM32_UUID ((uint32_t *)0x1FFFF7AC)
-float input = 0, output = 0, target = 3500;
-
 #define ADC_GRP1_NUM_CHANNELS   1
 #define ADC_GRP1_BUF_DEPTH      8
 
+static pid_t pid;
+static float input = 0, output = 0, target = 0;
 static adcsample_t samples[ADC_GRP1_NUM_CHANNELS * ADC_GRP1_BUF_DEPTH];
 
 /*
@@ -33,8 +34,22 @@ static void adccallback(ADCDriver *adcp, adcsample_t *buffer, size_t n) {
 
   (void)adcp;
   (void)n;
+  uint32_t i, tmp = 0;
   if (samples == buffer) {
-    input = buffer[4];
+
+    for (i = 0; i < n; i++) {
+        tmp += buffer[i];
+    }
+    input = tmp / n;
+    
+    if (input <= target) {
+        palClearLine(LINE_LED7_GREEN);
+        palSetLine(LINE_LED6_GREEN);
+    }
+    else {
+        palClearLine(LINE_LED6_GREEN);
+        palSetLine(LINE_LED7_GREEN);
+    }
   }
 }
 
@@ -51,11 +66,11 @@ static const ADCConversionGroup adcgrpcfg1 = {
   ADC_CFGR_CONT,            /* CFGR    */
   ADC_TR(0, 4095),          /* TR1     */
   {                         /* SMPR[2] */
-    ADC_SMPR1_SMP_AN0(ADC_SMPR_SMP_19P5),
+    ADC_SMPR1_SMP_AN1(ADC_SMPR_SMP_181P5),
     0
   },
   {                         /* SQR[4]  */
-    ADC_SQR1_SQ1_N(ADC_CHANNEL_IN0),
+    ADC_SQR1_SQ1_N(ADC_CHANNEL_IN1),
     0,
     0,
     0
@@ -72,32 +87,35 @@ static void gptcb(GPTDriver *drv) {
     
     (void)drv;
     pid_compute(&pid);
-    dacPutChannelX(&DACD1, 0, output);
+    dacPutChannelX(&DACD1, 0, (dacsample_t)output);
 }
 
 /*
  * GPT6 configuration.
  */
 static const GPTConfig gpt6cfg1 = {
-  .frequency    = 100U,
+  .frequency    = 10000U, // 10 KHz
   .callback     = gptcb,
   .cr2          = TIM_CR2_MMS_1,    /* MMS = 010 = TRGO on Update Event.    */
   .dier         = 0U
 };
 
+
 /*
  * Red LEDs blinker thread, times are in milliseconds.
  */
 static THD_WORKING_AREA(waThread1, 128);
 static THD_FUNCTION(Thread1, arg) {
+    
+  srand(osalOsGetSystemTimeX() + STM32_UUID[0]);
 
   (void)arg;
   chRegSetThreadName("blinker");
   while (true) {
-    palSetPad(GPIOE, GPIOE_LED10_RED);
+    palToggleLine(LINE_LED10_RED);
-    chThdSleepMilliseconds(500);
-    palClearPad(GPIOE, GPIOE_LED10_RED);
     chThdSleepMilliseconds(500);
+    
+    target = 1000 + (rand() % 2500); // Change the PID target every 500ms.
   }
 }
 
@@ -110,10 +128,10 @@ int main(void) {
   chSysInit();
 
   /*
-  * Set PA0 PA3 PA4 to Analog (ADC1_CH1, DAC1_CH1)
+  * Set PA0 PA3 PA4 to Analog (ADC1_CH2, DAC1_CH1)
   * You will have to connect these with a jumper wire
   */
-  palSetPadMode(GPIOA, 0, PAL_MODE_INPUT_ANALOG);
+  palSetPadMode(GPIOA, 1, PAL_MODE_INPUT_ANALOG);
   palSetPadMode(GPIOA, 3, PAL_MODE_INPUT_ANALOG);
 
   /*
@@ -122,29 +140,30 @@ int main(void) {
   adcStart(&ADCD1, NULL);
   dacStart(&DACD1, &dac1cfg1);
   gptStart(&GPTD6, &gpt6cfg1);
+  
+  /*
+   * Start PID
+   */
+  pid_create(&pid, &input, &output, &target, 1.0, 1.0, 1.0, PID_ON_M, PID_DIRECT);
+  pid_setOutputLimits(&pid, 0.0, 4095.0); // Max DAC range
+  pid_setSampleTime(&pid, 10);
+  pid_setMode(&pid, PID_AUTOMATIC);
 
   /*
    * Starting a continuous conversion.
    */
-  gptStartContinuous(&GPTD6, 2U);
+  gptStartContinuous(&GPTD6, 101U); // 10000 / 101
-  
-  pid_create(&pid, &input, &output, &target, 2.0, 5.0, 1.0, PID_ON_M, PID_DIRECT);
-  pid_setSampleTime(&pid, 10);
-  pid_setMode(&pid, PID_AUTOMATIC);
-  
-    /*
-   * Creates the blinker thread.
-   */
-  chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO, Thread1, NULL);
-  
   adcStartConversion(&ADCD1, &adcgrpcfg1, samples, ADC_GRP1_BUF_DEPTH);
-
+  
+  /*
+  * Creates the blinker thread.
+  */
+  chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO, Thread1, NULL);
 
   /*
    * Normal main() thread activity.
    */
   while (true) {
-
     chThdSleepMilliseconds(250);
     palToggleLine(LINE_LED3_RED);
   }