Make ppm/pwm input filtering configurable.

docs/Rx.md

@@ -26,4 +26,18 @@ Allows you to use MSP commands as the RC input.  Only 8 channel support to maint
 12 channels via serial supported currently.
 
  
+### Configuration
+
+See the Configuration document some some RX configuration examples.
+
+#### PPM/PWM input filtering.
+
+Hardware input filtering can be enabled if you are experiencing interference on the signal sent via your PWM/PPM RX.
+
+Use the `input_filtering_mode` cli command to select a mode.
+
+| Value | Meaning   |
+| ----- | --------- |
+| 0     | Disabled  |
+| 1     | Enabled   |
 

src/main/config/config.c

@@ -27,6 +27,7 @@
 
 #include "drivers/accgyro.h"
 #include "drivers/system.h"
+#include "drivers/pwm_rx.h"
 
 #include "sensors/sensors.h"
 #include "sensors/gyro.h"
@@ -244,6 +245,8 @@ static void resetConf(void)
     masterConfig.rxConfig.maxcheck = 1900;
     masterConfig.rxConfig.rssi_channel = 0;
 
+    masterConfig.inputFilteringMode = INPUT_FILTERING_DISABLED;
+
     masterConfig.retarded_arm = 0;              // disable arm/disarm on roll left/right
     masterConfig.airplaneConfig.flaps_speed = 0;
     masterConfig.fixedwing_althold_dir = 1;

src/main/config/config_master.h

@@ -57,6 +57,7 @@ typedef struct master_t {
     batteryConfig_t batteryConfig;
 
     rxConfig_t rxConfig;
+    inputFilteringMode_e inputFilteringMode;  // Use hardware input filtering, e.g. for OrangeRX PPM/PWM receivers.
 
     uint8_t retarded_arm;                   // allow disarsm/arm on throttle down + roll left/right
 

src/main/drivers/pwm_rx.c

@@ -38,7 +38,11 @@
 #define PWM_PORTS_OR_PPM_CAPTURE_COUNT PWM_INPUT_PORT_COUNT
 #endif
 
-void pwmICConfig(TIM_TypeDef *tim, uint8_t channel, uint16_t polarity); // from pwm_output.c
+#define INPUT_FILTER_TO_HELP_WITH_NOISE_FROM_OPENLRS_TELEMETRY_RX 0x03
+
+static inputFilteringMode_e inputFilteringMode;
+
+void pwmICConfig(TIM_TypeDef *tim, uint8_t channel, uint16_t polarity);
 
 typedef enum {
     INPUT_MODE_PPM,
@@ -105,6 +109,11 @@ void resetPPMDataReceivedState(void)
 
 #define MIN_CHANNELS_BEFORE_PPM_FRAME_CONSIDERED_VALID 4
 
+void pwmRxInit(inputFilteringMode_e initialInputFilteringMode)
+{
+    inputFilteringMode = initialInputFilteringMode;
+}
+
 static void ppmInit(void)
 {
     ppmDev.pulseIndex   = 0;
@@ -232,8 +241,6 @@ static void pwmGPIOConfig(GPIO_TypeDef *gpio, uint32_t pin, GPIO_Mode mode)
     gpioInit(gpio, &cfg);
 }
 
-#define INPUT_FILTER_TO_HELP_WITH_NOISE_FROM_OPENLRS_TELEMETRY_RX 0x03
-
 void pwmICConfig(TIM_TypeDef *tim, uint8_t channel, uint16_t polarity)
 {
     TIM_ICInitTypeDef TIM_ICInitStructure;
@@ -243,7 +250,12 @@ void pwmICConfig(TIM_TypeDef *tim, uint8_t channel, uint16_t polarity)
     TIM_ICInitStructure.TIM_ICPolarity = polarity;
     TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
     TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
+
+    if (inputFilteringMode == INPUT_FILTERING_ENABLED) {
         TIM_ICInitStructure.TIM_ICFilter = INPUT_FILTER_TO_HELP_WITH_NOISE_FROM_OPENLRS_TELEMETRY_RX;
+    } else {
+        TIM_ICInitStructure.TIM_ICFilter = 0x00;
+    }
 
     TIM_ICInit(tim, &TIM_ICInitStructure);
 }

src/main/drivers/pwm_rx.h

@@ -17,6 +17,11 @@
 
 #pragma once
 
+typedef enum {
+    INPUT_FILTERING_DISABLED = 0,
+    INPUT_FILTERING_ENABLED
+} inputFilteringMode_e;
+
 void ppmInConfig(uint8_t timerIndex);
 void pwmInConfig(uint8_t timerIndex, uint8_t channel);
 
@@ -24,3 +29,5 @@ uint16_t pwmRead(uint8_t channel);
 
 bool isPPMDataBeingReceived(void);
 void resetPPMDataReceivedState(void);
+
+void pwmRxInit(inputFilteringMode_e initialInputFilteringMode);

src/main/flight/altitudehold.c

@@ -26,6 +26,7 @@
 
 #include "drivers/accgyro.h"
 #include "drivers/serial.h"
+#include "drivers/pwm_rx.h"
 
 // FIXME remove dependency on currentProfile and masterConfig globals and clean up include file list.
 

src/main/io/serial_cli.c

@@ -32,6 +32,7 @@
 #include "drivers/accgyro.h"
 #include "drivers/serial.h"
 #include "drivers/bus_i2c.h"
+#include "drivers/pwm_rx.h"
 #include "flight/flight.h"
 #include "flight/mixer.h"
 #include "flight/failsafe.h"
@@ -167,6 +168,7 @@ const clivalue_t valueTable[] = {
     { "min_check", VAR_UINT16, &masterConfig.rxConfig.mincheck, PWM_RANGE_ZERO, PWM_RANGE_MAX },
     { "max_check", VAR_UINT16, &masterConfig.rxConfig.maxcheck, PWM_RANGE_ZERO, PWM_RANGE_MAX },
     { "rssi_channel", VAR_INT8, &masterConfig.rxConfig.rssi_channel, 0, MAX_SUPPORTED_RC_CHANNEL_COUNT },
+    { "input_filtering_mode", VAR_INT8, &masterConfig.inputFilteringMode, 0, 1 },
 
     { "min_throttle", VAR_UINT16, &masterConfig.escAndServoConfig.minthrottle, PWM_RANGE_ZERO, PWM_RANGE_MAX },
     { "max_throttle", VAR_UINT16, &masterConfig.escAndServoConfig.maxthrottle, PWM_RANGE_ZERO, PWM_RANGE_MAX },

src/main/io/serial_msp.c

@@ -31,6 +31,7 @@
 #include "drivers/accgyro.h"
 #include "drivers/serial.h"
 #include "drivers/bus_i2c.h"
+#include "drivers/pwm_rx.h"
 
 #include "flight/flight.h"
 #include "flight/mixer.h"

src/main/main.c

@@ -35,6 +35,7 @@
 #include "drivers/serial_uart.h"
 #include "drivers/accgyro.h"
 #include "drivers/pwm_mapping.h"
+#include "drivers/pwm_rx.h"
 #include "drivers/adc.h"
 
 #include "flight/flight.h"
@@ -204,6 +205,8 @@ void init(void)
         pwm_params.idlePulse = 0; // brushed motors
     pwm_params.servoCenterPulse = masterConfig.rxConfig.midrc;
 
+    pwmRxInit(masterConfig.inputFilteringMode);
+
     pwmOutputConfiguration_t *pwmOutputConfiguration = pwmInit(&pwm_params);
 
     mixerUsePWMOutputConfiguration(pwmOutputConfiguration);

src/main/mw.c

@@ -32,6 +32,7 @@
 #include "drivers/gpio.h"
 #include "drivers/system.h"
 #include "drivers/serial.h"
+#include "drivers/pwm_rx.h"
 
 #include "flight/flight.h"
 #include "sensors/sensors.h"