changed I2C watchdog timer implementation, as LPTMR was already used by key scanner

left/src/i2c_watchdog.c

@@ -3,38 +3,34 @@
 #include "i2c_watchdog.h"
 #include "test_led.h"
 #include "init_peripherals.h"
+#include "main.h"
 
 /* NOTE: Because of a bug in the ROM bootloader of the KL03Z, the watchdog timer is disabled and cannot be re-enabled.
  * See https://community.nxp.com/thread/457893
  * Therefore the hardware watchdog timer cannot be used without an extra way to enter bootloader or application mode.
  */
-
+#if KEY_USE_I2C_WATCHDOG_TIMER
-#define WATCH_ENABLE_WATCHDOG   (1)  /* additionally, un-comment InitI2cWatchdog() in init_peripherals.c */
-
-#if WATCH_ENABLE_WATCHDOG
   static uint32_t prevWatchdogCounter = 0;
-#endif
   static uint32_t I2cWatchdog_RecoveryCounter; /* counter for how many times we had to recover and restart */
+#endif
 
 void InitI2cWatchdog(void)
 {
-    lptmr_config_t lptmrConfig;
-    LPTMR_GetDefaultConfig(&lptmrConfig);
-    LPTMR_Init(LPTMR0, &lptmrConfig);
-    LPTMR_SetTimerPeriod(LPTMR0, USEC_TO_COUNT(LPTMR_USEC_COUNT, LPTMR_SOURCE_CLOCK)); /* set LPTM for a 100 ms period */
-    LPTMR_EnableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
-    EnableIRQ(LPTMR0_IRQn);
-    LPTMR_StartTimer(LPTMR0);
 }
 
-#if WATCH_ENABLE_WATCHDOG
+#if KEY_USE_I2C_WATCHDOG_TIMER
-void I2C_WATCHDOG_LPTMR_HANDLER(void)
+void RunWatchdog(void)
 {
 	static volatile uint32_t I2cWatchdog_WatchCounter = 0; /* counter for timer */
+	static int cntr = 0;
+
+	cntr++;
+	if (cntr==100) { /* we get called from KEY_SCANNER_HANDLER() which runs at 1ms, thus scaling down by 100 here to get 100 ms period */
+		cntr=0;
 		TEST_LED_TOGGLE();
 		I2cWatchdog_WatchCounter++;
 
-    if (I2cWatchdog_WatchCounter>1) { /* do not check within the first 100 ms, as I2C might not be running yet */
+		if (I2cWatchdog_WatchCounter>10) { /* do not check within the first 1000 ms, as I2C might not be running yet */
 			if (I2C_Watchdog == prevWatchdogCounter) { // Restart I2C if there hasn't been any interrupt during 100 ms. I2C_Watchdog gets incremented for every I2C transaction
 		//        NVIC_SystemReset();
 				I2cWatchdog_RecoveryCounter++;
@@ -43,7 +39,6 @@ void I2C_WATCHDOG_LPTMR_HANDLER(void)
 			}
 		}
 		prevWatchdogCounter = I2C_Watchdog; /* remember previous counter */
-
+	}
-    LPTMR_ClearStatusFlags(LPTMR0, kLPTMR_TimerCompareFlag);
 }
 #endif

left/src/init_peripherals.c

@@ -10,6 +10,7 @@
 #include "slave_protocol_handler.h"
 #include "i2c_watchdog.h"
 #include "debug_over_spi.h"
+#include "main.h"
 
 i2c_slave_config_t slaveConfig;
 i2c_slave_handle_t slaveHandle;
@@ -87,5 +88,7 @@ void InitPeripherals(void)
     LedPwm_Init();
     DebugOverSpi_Init();
     InitI2c();
+#if KEY_USE_I2C_WATCHDOG_TIMER
     InitI2cWatchdog();
+#endif
 }

left/src/key_scanner.c

@@ -1,10 +1,16 @@
 #include "fsl_lptmr.h"
 #include "key_scanner.h"
 #include "main.h"
+#if KEY_USE_I2C_WATCHDOG_TIMER
+  #include "i2c_watchdog.h"
+#endif
 
 void KEY_SCANNER_HANDLER(void)
 {
     KeyMatrix_ScanRow(&keyMatrix);
+#if KEY_USE_I2C_WATCHDOG_TIMER
+    RunWatchdog();
+#endif
     LPTMR_ClearStatusFlags(KEY_SCANNER_LPTMR_BASEADDR, kLPTMR_TimerCompareFlag);
 }
 

left/src/main.h

@@ -14,4 +14,6 @@
 
     extern key_matrix_t keyMatrix;
 
+   #define KEY_USE_I2C_WATCHDOG_TIMER   (1) /* if set to 1, every 100 ms the I2C communication is checked */
+
 #endif