slight refactoring of PPM/PWM failsafe to make it actually work and honor failsafeThreshold value.

src/drv_pwm.c

@@ -242,13 +242,27 @@ static pwmPortData_t *pwmInConfig(uint8_t port, timerCCCallbackPtr callback, uin
     return p;
 }
 
+static void failsafeCheck(uint8_t channel, uint16_t pulse)
+{
+    static uint8_t goodPulses;
+    
+    if (channel < 4 && pulse > failsafeThreshold)
+        goodPulses |= (1 << channel);       // if signal is valid - mark channel as OK
+    if (goodPulses == 0x0F) {               // If first four chanells have good pulses, clear FailSafe counter
+        goodPulses = 0;
+        if (failsafeCnt > 20)
+            failsafeCnt -= 20;
+        else
+            failsafeCnt = 0;
+    }
+}
+
 static void ppmCallback(uint8_t port, uint16_t capture)
 {
     uint16_t diff;
     static uint16_t now;
     static uint16_t last = 0;
     static uint8_t chan = 0;
-    static uint8_t GoodPulses;
 
     last = now;
     now = capture;
@@ -257,20 +271,11 @@ static void ppmCallback(uint8_t port, uint16_t capture)
     if (diff > 2700) { // Per http://www.rcgroups.com/forums/showpost.php?p=21996147&postcount=3960 "So, if you use 2.5ms or higher as being the reset for the PPM stream start, you will be fine. I use 2.7ms just to be safe."
         chan = 0;
     } else {
-        if (diff > 750 && diff < 2250 && chan < MAX_INPUTS) {   // 750 to 2250 ms is our 'valid' channel range
+        if (diff > PULSE_MIN && diff < PULSE_MAX && chan < MAX_INPUTS) {   // 750 to 2250 ms is our 'valid' channel range
             captures[chan] = diff;
-            if (chan < 4 && diff > failsafeThreshold)
-                GoodPulses |= (1 << chan);      // if signal is valid - mark channel as OK
-            if (GoodPulses == 0x0F) {           // If first four chanells have good pulses, clear FailSafe counter
-                GoodPulses = 0;
-                if (failsafeCnt > 20)
-                    failsafeCnt -= 20;
-                else
-                    failsafeCnt = 0;
-            }
+            failsafeCheck(chan, diff);
         }
         chan++;
-        failsafeCnt = 0;
     }
 }
 
@@ -284,12 +289,13 @@ static void pwmCallback(uint8_t port, uint16_t capture)
         pwmPorts[port].fall = capture;
         // compute capture
         pwmPorts[port].capture = pwmPorts[port].fall - pwmPorts[port].rise;
-        captures[pwmPorts[port].channel] = pwmPorts[port].capture;
+        if (pwmPorts[port].capture > PULSE_MIN && pwmPorts[port].capture < PULSE_MAX) { // valid pulse width
+            captures[pwmPorts[port].channel] = pwmPorts[port].capture;
+            failsafeCheck(pwmPorts[port].channel, pwmPorts[port].capture);
+        }
         // switch state
         pwmPorts[port].state = 0;
         pwmICConfig(timerHardware[port].tim, timerHardware[port].channel, TIM_ICPolarity_Rising);
-        // reset failsafe
-        failsafeCnt = 0;
     }
 }
 

src/drv_pwm.h

@@ -3,7 +3,9 @@
 #define MAX_MOTORS  12
 #define MAX_SERVOS  8
 #define MAX_INPUTS  8
-#define PULSE_1MS       (1000) // 1ms pulse width
+#define PULSE_1MS   (1000)      // 1ms pulse width
+#define PULSE_MIN   (750)       // minimum PWM pulse width which is considered valid
+#define PULSE_MAX   (2250)      // maximum PWM pulse width which is considered valid
 
 typedef struct drv_pwm_config_t {
     bool enableInput;

src/drv_pwm_fy90q.c

@@ -85,7 +85,7 @@ static void ppmIRQHandler(TIM_TypeDef *tim)
     if (diff > 4000) {
         chan = 0;
     } else {
-        if (diff > 750 && diff < 2250 && chan < 8) {   // 750 to 2250 ms is our 'valid' channel range
+        if (diff > PULSE_MIN && diff < PULSE_MAX && chan < 8) {   // 750 to 2250 ms is our 'valid' channel range
             Inputs[chan].capture = diff;
             if (chan < 4 && diff > FAILSAFE_DETECT_TRESHOLD)
                 GoodPulses |= (1 << chan);      // if signal is valid - mark channel as OK

src/mw.c

@@ -226,13 +226,7 @@ void annexCode(void)
 
 uint16_t pwmReadRawRC(uint8_t chan)
 {
-    uint16_t data;
-
-    data = pwmRead(mcfg.rcmap[chan]);
-    if (data < 750 || data > 2250)
-        data = mcfg.midrc;
-
-    return data;
+    return pwmRead(mcfg.rcmap[chan]);
 }
 
 void computeRC(void)