CC3D - don't share timer between PPM capture and motor output

A periodic glitch happens on AUX channels when using OneShot on CC3D,
especially with faster update loops. This is caused by a race condition
while forcing timer overflows and sharing the timer for PPM capture.
It causes the craft the fall out of the sky when using a switch to arm.

* Remap PPM in from S1_IN to S6_IN
* Remap RSSI_ADC from S6_IN to S3_IN
* Block PWM12/S6_OUT from being used with Oneshot/brushed motors so
TIM2 (PPM_IN timer) doesn't change prescaler or is manually overflowed
* Allow only one feature out of SOFTSERIAL/RSSI_ADC/SONAR, since they
will now share the same pin
* Update docs to reflect port changes and restrictions

This fixes cleanflight/cleanflight#1748,
fixes borisbstyle/betaflight#64, fixes borisbstyle/betaflight#127

fix BP6

docs/Board - CC3D.md

@@ -22,12 +22,14 @@ The 8 pin RC_Input connector has the following pinouts when used in RX_PPM/RX_SE
 | --- | --------- | -------------------------------- |
 | 1   | Ground    |                                  |
 | 2   | +5V       |                                  |
-| 3   | PPM Input | Enable `feature RX_PPM`          | 
+| 3   | Unused |  | 
 | 4   | SoftSerial1 TX / Sonar trigger | |
-| 5   | SoftSerial1 RX / Sonar Echo    | |
+| 5   | SoftSerial1 RX / Sonar Echo / RSSI_ADC    | Used either for SOFTSERIAL, SONAR or RSSI_ADC*. Only one feature can be enabled at any time. |
 | 6   | Current   | Enable `feature CURRENT_METER`.  Connect to the output of a current sensor, 0v-3.3v input |
 | 7   | Battery Voltage sensor | Enable `feature VBAT`. Connect to main battery using a voltage divider, 0v-3.3v input |
-| 8   | RSSI      | Enable `feature RSSI_ADC`.  Connect to the output of a PWM-RSSI conditioner, 0v-3.3v input |
+| 8   | PPM Input | Enable `feature RX_PPM` |
+
+*Connect to the output of a PWM-RSSI conditioner, 0v-3.3v input. 
 
 The 6 pin RC_Output connector has the following pinouts when used in RX_PPM/RX_SERIAL mode
 

src/main/config/config.c

@@ -890,9 +890,19 @@ void validateAndFixConfig(void)
     masterConfig.telemetryConfig.telemetry_inversion = 1;
 #endif
 
-#if defined(CC3D) && defined(SONAR) && defined(USE_SOFTSERIAL1)
+
-    if (feature(FEATURE_SONAR) && feature(FEATURE_SOFTSERIAL)) {
+#if defined(LED_STRIP) && defined(TRANSPONDER)
-        featureClear(FEATURE_SONAR);
+    if ((WS2811_DMA_TC_FLAG == TRANSPONDER_DMA_TC_FLAG) && featureConfigured(FEATURE_TRANSPONDER) && featureConfigured(FEATURE_LED_STRIP)) {
+        featureClear(FEATURE_LED_STRIP);
+    }
+#endif
+
+#if defined(CC3D) && defined(SONAR) && defined(USE_SOFTSERIAL1) && defined(RSSI_ADC_GPIO)
+    // shared pin
+    if ((featureConfigured(FEATURE_SONAR) + featureConfigured(FEATURE_SOFTSERIAL) + featureConfigured(FEATURE_RSSI_ADC)) > 1) {
+    	featureClear(FEATURE_SONAR);
+    	featureClear(FEATURE_SOFTSERIAL);
+    	featureClear(FEATURE_RSSI_ADC);
     }
 #endif
 

src/main/drivers/pwm_mapping.c

@@ -146,18 +146,17 @@ static const uint16_t airPWM[] = {
 
 #ifdef CC3D
 static const uint16_t multiPPM[] = {
-    PWM1  | (MAP_TO_PPM_INPUT << 8),     // PPM input
+    PWM6  | (MAP_TO_PPM_INPUT << 8),     // PPM input
-    PWM7  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
+    PWM7  | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #1
-    PWM8  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
+    PWM8  | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #2
-    PWM9  | (MAP_TO_MOTOR_OUTPUT << 8),
+    PWM9  | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #3
-    PWM10 | (MAP_TO_MOTOR_OUTPUT << 8),
+    PWM10 | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #4
     PWM11 | (MAP_TO_MOTOR_OUTPUT << 8),
     PWM12 | (MAP_TO_MOTOR_OUTPUT << 8),
     PWM2  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     PWM3  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     PWM4  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     PWM5  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
-    PWM6  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     0xFFFF
 };
 
@@ -178,7 +177,7 @@ static const uint16_t multiPWM[] = {
 };
 
 static const uint16_t airPPM[] = {
-    PWM1  | (MAP_TO_PPM_INPUT << 8),     // PPM input
+    PWM6  | (MAP_TO_PPM_INPUT << 8),     // PPM input
     PWM7  | (MAP_TO_MOTOR_OUTPUT  << 8),
     PWM8  | (MAP_TO_MOTOR_OUTPUT  << 8),
     PWM9  | (MAP_TO_SERVO_OUTPUT  << 8),
@@ -189,7 +188,6 @@ static const uint16_t airPPM[] = {
     PWM3  | (MAP_TO_SERVO_OUTPUT  << 8),
     PWM4  | (MAP_TO_SERVO_OUTPUT  << 8),
     PWM5  | (MAP_TO_SERVO_OUTPUT  << 8),
-    PWM6  | (MAP_TO_SERVO_OUTPUT  << 8),
     0xFFFF
 };
 
@@ -209,17 +207,16 @@ static const uint16_t airPWM[] = {
     0xFFFF
 };
 static const uint16_t multiPPM_BP6[] = {
-    PWM1  | (MAP_TO_PPM_INPUT << 8),     // PPM input
+    PWM6  | (MAP_TO_PPM_INPUT << 8),     // PPM input
-    PWM7  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
+    PWM7  | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #1
-    PWM8  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
+    PWM8  | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #2
-    PWM9  | (MAP_TO_MOTOR_OUTPUT << 8),
+    PWM9  | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #3
-    PWM10 | (MAP_TO_MOTOR_OUTPUT << 8),
+    PWM10 | (MAP_TO_MOTOR_OUTPUT << 8),      // motor #4
     PWM11 | (MAP_TO_MOTOR_OUTPUT << 8),
     PWM2  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     PWM3  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     PWM4  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     PWM5  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
-    PWM6  | (MAP_TO_MOTOR_OUTPUT << 8),      // Swap to servo if needed
     0xFFFF
 };
 
@@ -239,7 +236,7 @@ static const uint16_t multiPWM_BP6[] = {
 };
 
 static const uint16_t airPPM_BP6[] = {
-    PWM1  | (MAP_TO_PPM_INPUT << 8),     // PPM input
+    PWM6  | (MAP_TO_PPM_INPUT << 8),     // PPM input
     PWM7  | (MAP_TO_MOTOR_OUTPUT  << 8),
     PWM8  | (MAP_TO_MOTOR_OUTPUT  << 8),
     PWM9  | (MAP_TO_SERVO_OUTPUT  << 8),
@@ -249,7 +246,6 @@ static const uint16_t airPPM_BP6[] = {
     PWM3  | (MAP_TO_SERVO_OUTPUT  << 8),
     PWM4  | (MAP_TO_SERVO_OUTPUT  << 8),
     PWM5  | (MAP_TO_SERVO_OUTPUT  << 8),
-    PWM6  | (MAP_TO_SERVO_OUTPUT  << 8),
     0xFFFF
 };
 
@@ -784,11 +780,6 @@ if (init->useBuzzerP6) {
 #endif
 
         if (type == MAP_TO_PPM_INPUT) {
-#ifdef CC3D
-            if (init->useOneshot || isMotorBrushed(init->motorPwmRate)) {
-                ppmAvoidPWMTimerClash(timerHardwarePtr, TIM4);
-            }
-#endif
 #ifdef SPARKY
             if (init->useOneshot || isMotorBrushed(init->motorPwmRate)) {
                 ppmAvoidPWMTimerClash(timerHardwarePtr, TIM2);
@@ -799,6 +790,14 @@ if (init->useBuzzerP6) {
             pwmInConfig(timerHardwarePtr, channelIndex);
             channelIndex++;
         } else if (type == MAP_TO_MOTOR_OUTPUT) {
+
+#ifdef CC3D
+            if (init->useOneshot || isMotorBrushed(init->motorPwmRate)){
+            	// Skip it if it would cause PPM capture timer to be reconfigured or manually overflowed
+            	if (timerHardwarePtr->tim == TIM2)
+            		continue;
+            }
+#endif
             if (init->useOneshot) {
                 if (init->useFastPWM) {
                     fastPWMMotorConfig(timerHardwarePtr, pwmOutputConfiguration.motorCount, init->motorPwmRate, init->idlePulse);

src/main/drivers/timer.c

@@ -68,12 +68,12 @@ const timerHardware_t timerHardware[USABLE_TIMER_CHANNEL_COUNT] = {
 
 #ifdef CC3D
 const timerHardware_t timerHardware[USABLE_TIMER_CHANNEL_COUNT] = {
-    { TIM4, GPIOB, Pin_6, TIM_Channel_1, TIM4_IRQn, 0, Mode_IPD}, // S1_IN - PPM
+    { TIM4, GPIOB, Pin_6, TIM_Channel_1, TIM4_IRQn, 0, Mode_IPD}, // S1_IN
-    { TIM3, GPIOB, Pin_5, TIM_Channel_2, TIM3_IRQn, 0, Mode_IPD}, // S2_IN - SoftSerial TX - GPIO_PartialRemap_TIM3
+    { TIM3, GPIOB, Pin_5, TIM_Channel_2, TIM3_IRQn, 0, Mode_IPD}, // S2_IN - SoftSerial TX - GPIO_PartialRemap_TIM3 / Sonar trigger
-    { TIM3, GPIOB, Pin_0, TIM_Channel_3, TIM3_IRQn, 0, Mode_IPD}, // S3_IN - SoftSerial RX
+    { TIM3, GPIOB, Pin_0, TIM_Channel_3, TIM3_IRQn, 0, Mode_IPD}, // S3_IN - SoftSerial RX / Sonar echo / RSSI ADC
-    { TIM3, GPIOB, Pin_1, TIM_Channel_4, TIM3_IRQn, 0, Mode_IPD}, // S4_IN -  Current
+    { TIM3, GPIOB, Pin_1, TIM_Channel_4, TIM3_IRQn, 0, Mode_IPD}, // S4_IN - Current
-    { TIM2, GPIOA, Pin_0, TIM_Channel_1, TIM2_IRQn, 0, Mode_IPD}, // S5_IN -  Vbattery
+    { TIM2, GPIOA, Pin_0, TIM_Channel_1, TIM2_IRQn, 0, Mode_IPD}, // S5_IN - Vbattery
-    { TIM2, GPIOA, Pin_1, TIM_Channel_2, TIM2_IRQn, 0, Mode_IPD}, // S6_IN -  RSSI
+    { TIM2, GPIOA, Pin_1, TIM_Channel_2, TIM2_IRQn, 0, Mode_IPD}, // S6_IN - PPM IN
 
     { TIM4, GPIOB, Pin_9, TIM_Channel_4, TIM4_IRQn, 1, GPIO_Mode_AF_PP},    // S1_OUT
     { TIM4, GPIOB, Pin_8, TIM_Channel_3, TIM4_IRQn, 1, GPIO_Mode_AF_PP},    // S2_OUT

src/main/target/CC3D/target.h

@@ -108,9 +108,9 @@
 #define VBAT_ADC_GPIO_PIN           GPIO_Pin_0
 #define VBAT_ADC_CHANNEL            ADC_Channel_0
 
-#define RSSI_ADC_GPIO               GPIOA
+#define RSSI_ADC_GPIO               GPIOB
-#define RSSI_ADC_GPIO_PIN           GPIO_Pin_1
+#define RSSI_ADC_GPIO_PIN           GPIO_Pin_0
-#define RSSI_ADC_CHANNEL            ADC_Channel_1
+#define RSSI_ADC_CHANNEL            ADC_Channel_8
 
 #define GPS
 #define LED_STRIP