RC pwm signal read fixes

Re-work on the RC pwm input signal timeout

Inc/config.h

@@ -288,8 +288,8 @@
   // Min / Max values of each channel (use DEBUG to determine these values)
   #define PWM_CH1_MAX                 1000    // (0 - 1000)
   #define PWM_CH1_MIN                -1000    // (-1000 - 0)
-  #define PWM_CH2_MAX                 500     // (0 - 1000)
+  #define PWM_CH2_MAX                 1000    // (0 - 1000)
-  #define PWM_CH2_MIN                 -800    // (-1000 - 0)
+  #define PWM_CH2_MIN                -1000    // (-1000 - 0)
   // right sensor board cable. Only read once during startup
   #define BUTTONS_RIGHT               // use right sensor board cable for button inputs. Disable DEBUG_SERIAL_USART3!
   #define FILTER                      6553    // 0.1f [-] fixdt(0,16,16) lower value == softer filter [0, 65535] = [0.0 - 1.0].

Inc/defines.h

@@ -170,8 +170,6 @@ void PPM_ISR_Callback(void);
 void PWM_Init(void);
 //void PWM_ISR_CH1_Callback(void);
 void PWM_ISR_CH2_Callback(void);
-void PWM_SysTick_Callback(void);
-int PWM_Signal_Correct(int16_t x, int16_t max, int16_t min);
 
 // Sideboard definitions
 #define LED1_SET     				(0x01)

Inc/util.h

@@ -73,6 +73,7 @@ void poweroffPressCheck(void);
 
 // Read Command Function
 void readCommand(void);
+int  PWM_Signal_Correct(int16_t u,  int16_t min, int16_t max);
 
 // Sideboard functions
 void sideboardLeds(uint8_t *leds);

Src/control.c

@@ -123,25 +123,14 @@ uint32_t pwm_timeout = 0;
 
 #define IN_RANGE(x, low, up) (((x) >= (low)) && ((x) <= (up)))
 
-int PWM_Signal_Correct(int16_t x, int16_t max, int16_t min) {
-  int outVal = 0;
-  if(x > -PWM_DEADBAND && x < PWM_DEADBAND) {
-    outVal = 0;
-  } else if(x > 0) {
-    outVal = (float)CLAMP(x-PWM_DEADBAND, 0, max - PWM_DEADBAND) / (max - PWM_DEADBAND) * 1000;
-  } else {
-    outVal = 0 - ((float)CLAMP(x+PWM_DEADBAND, min + PWM_DEADBAND, 0) / (min + PWM_DEADBAND) * 1000);
-  }
-  return outVal;
-}
-
 /*
 void PWM_ISR_CH1_Callback(void) {
   // Dummy loop with 16 bit count wrap around
   uint16_t rc_signal = TIM3->CNT;
   TIM3->CNT = 0;
 
-  if (IN_RANGE(rc_signal, 900, 2100)){
+  // The interval check below should be larger than the feasible PWM interval of ~[500, 2500] ms
+  if (IN_RANGE(rc_signal, 200, 4000)){
     timeout = 0;
     pwm_timeout = 0;
     pwm_captured_ch1_value = CLAMP(rc_signal, 1000, 2000) - 1000;
@@ -154,7 +143,8 @@ void PWM_ISR_CH2_Callback(void) {
   uint16_t rc_signal = TIM2->CNT;
   TIM2->CNT = 0;
 
-  if (IN_RANGE(rc_signal, 900, 2100)){
+  // The interval check below should be larger than the feasible PWM interval of ~[900, 2100] ms
+  if (IN_RANGE(rc_signal, 200, 3000)){
     timeout = 0;
     pwm_timeout = 0;
     pwm_captured_ch2_value = CLAMP(rc_signal, 1000, 2000) - 1000;
@@ -164,11 +154,11 @@ void PWM_ISR_CH2_Callback(void) {
 // SysTick executes once each ms
 void PWM_SysTick_Callback(void) {
   pwm_timeout++;
-  // Stop after 500 ms without PPM signal
+  // Stop after 500 ms without PWM signal
   if(pwm_timeout > 500) {
     //pwm_captured_ch1_value = 500;
     pwm_captured_ch2_value = 500;
-    pwm_timeout = 0;
+    pwm_timeout = 500;          // limit the timeout to max timeout value of 500 ms
   }
 }
 

Src/main.c

@@ -251,8 +251,8 @@ int main(void) {
       // speedL = CLAMP((int)(speed * SPEED_COEFFICIENT +  steer * STEER_COEFFICIENT), INPUT_MIN, INPUT_MA);
       mixerFcn(speed << 4, steer << 4, &speedR, &speedL);   // This function implements the equations above
 
-      // ####### SET OUTPUTS (if the target change is less than +/- 50) #######
+      // ####### SET OUTPUTS (if the target change is less than +/- 100) #######
-      if ((speedL > lastSpeedL-50 && speedL < lastSpeedL+50) && (speedR > lastSpeedR-50 && speedR < lastSpeedR+50) && timeout < TIMEOUT) {
+      if ((speedL > lastSpeedL-100 && speedL < lastSpeedL+100) && (speedR > lastSpeedR-100 && speedR < lastSpeedR+100) && timeout < TIMEOUT) {
         #ifdef INVERT_R_DIRECTION
           pwmr = speedR;
         #else

Src/util.c

@@ -649,8 +649,8 @@ void readCommand(void) {
     #endif
 
     #ifdef CONTROL_PWM
-      cmd1 = 0; // CLAMP(PWM_Signal_Correct((pwm_captured_ch1_value - 500) * 2, PWM_CH1_MAX, PWM_CH1_MIN), INPUT_MIN, INPUT_MAX);
+      cmd1 = 0; // CLAMP(PWM_Signal_Correct((pwm_captured_ch1_value - 500) * 2, PWM_CH1_MIN, PWM_CH1_MAX), INPUT_MIN, INPUT_MAX);
-      cmd2 = CLAMP(PWM_Signal_Correct((pwm_captured_ch2_value - 500) * 2, PWM_CH2_MAX, PWM_CH2_MIN), INPUT_MIN, INPUT_MAX);
+      cmd2 = CLAMP(PWM_Signal_Correct((pwm_captured_ch2_value - 500) * 2, PWM_CH2_MIN, PWM_CH2_MAX), INPUT_MIN, INPUT_MAX);
     #endif
 
     #ifdef CONTROL_ADC
@@ -811,7 +811,6 @@ void readCommand(void) {
         if (main_loop_counter % 30 == 0) {
           HAL_UART_DMAStop(&huart3);                
           HAL_UART_Receive_DMA(&huart3, (uint8_t *)&Sideboard_Rnew, sizeof(Sideboard_Rnew));
-          Sideboard_Rnew.start = 0xFFFF;              // Change the Start Frame to avoid entering again here if no data is received
         }
       }
       timeoutFlagSerial = timeoutFlagSerial_R;
@@ -840,6 +839,22 @@ void readCommand(void) {
 }
 
 
+ /*
+ * PWM Signal Correction
+ * This function realizes a dead-band around 0 and scales the input within a min and a max
+ */
+int PWM_Signal_Correct(int16_t u,  int16_t min, int16_t max) {
+  int outVal = 0;
+  if(u > -PWM_DEADBAND && u < PWM_DEADBAND) {
+    outVal = 0;
+  } else if(u > 0) {
+    outVal = (INPUT_MAX * CLAMP(u - PWM_DEADBAND, 0, max - PWM_DEADBAND)) / (max - PWM_DEADBAND);
+  } else {
+    outVal = (INPUT_MIN * CLAMP(u + PWM_DEADBAND, min + PWM_DEADBAND, 0)) / (min + PWM_DEADBAND);
+  }
+  return outVal;
+}
+
 
 /* =========================== Sideboard Functions =========================== */