Added detection of soft reset and swich of bind mode

after first hard reset (power on) if hardware bind plug is not
configured. Now completly tested.

src/main/drivers/system.h

@@ -30,6 +30,7 @@ void failureMode(uint8_t mode);
 // bootloader/IAP
 void systemReset(void);
 void systemResetToBootloader(void);
+bool isMPUSoftReset(void);
 
 void enableGPIOPowerUsageAndNoiseReductions(void);
 // current crystal frequency - 8 or 12MHz

src/main/drivers/system_stm32f10x.c

@@ -22,11 +22,19 @@
 #include "platform.h"
 
 #include "gpio.h"
+#include "system.h"
 
 #define AIRCR_VECTKEY_MASK    ((uint32_t)0x05FA0000)
+#define BKP_SOFTRESET (0x50F7B007)
 
 void systemReset(void)
 {
+    // write magic value that we're doing a soft reset
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);
+    PWR->CR |= PWR_CR_DBP;
+    *((uint16_t *)BKP_BASE + 0x04) = BKP_SOFTRESET & 0xffff;
+    *((uint16_t *)BKP_BASE + 0x08) = (BKP_SOFTRESET & 0xffff0000) >> 16;
+
     // Generate system reset
     SCB->AIRCR = AIRCR_VECTKEY_MASK | (uint32_t)0x04;
 }
@@ -52,3 +60,11 @@ void enableGPIOPowerUsageAndNoiseReductions(void)
     gpioInit(GPIOB, &gpio);
     gpioInit(GPIOC, &gpio);
 }
+
+bool isMPUSoftReset(void)
+{
+    if ((*((uint16_t *)BKP_BASE + 0x04) | *((uint16_t *)BKP_BASE + 0x08) << 16) == BKP_SOFTRESET)
+        return true;
+    else
+        return false;
+}

src/main/drivers/system_stm32f30x.c

@@ -67,3 +67,9 @@ void enableGPIOPowerUsageAndNoiseReductions(void)
     gpioInit(GPIOE, &gpio);
     gpioInit(GPIOF, &gpio);
 }
+
+bool isMPUSoftReset(void)
+{
+    // not implemented yet for STM32F3xx
+    return false;
+}

src/main/rx/spektrum.c

@@ -175,8 +175,8 @@ void spektrumBind(rxConfig_t *rxConfig)
     spekBindPort = BIND_PORT;
     spekBindPin = BIND_PIN;
 
-    // don't try to bind if: bind flag is out of range
-    if (rxConfig->spektrum_sat_bind == 0 || rxConfig->spektrum_sat_bind > 10)
+    // don't try to bind if: here after soft reset or bind flag is out of range
+    if (isMPUSoftReset() || rxConfig->spektrum_sat_bind == 0 || rxConfig->spektrum_sat_bind > 10)
         return;
 
     gpio.speed = Speed_2MHz;
@@ -196,5 +196,15 @@ void spektrumBind(rxConfig_t *rxConfig)
         digitalHi(spekBindPort, spekBindPin);
         delayMicroseconds(120);
     }
+
+#ifndef HARDWARE_BIND_PLUG
+    // If we came here as a result of hard  reset (power up, with mcfg.spektrum_sat_bind set), then reset it back to zero and write config
+    // Don't reset if hardware bind plug is present
+    if (!isMPUSoftReset()) {
+        rxConfig->spektrum_sat_bind = 0;
+        writeEEPROM(1, true);
+    }
+#endif
+
 }
 #endif