William Marsh / Mbed OS Watchdog_sample_fail

Example of watchdog causing a reset

Fork of KL25Z_WATCHDOG_USBSERIAL by Manel Marin

main.cpp@1:159a09ac60ba, 2017-02-28 (annotated)

Committer:
WilliamMarshQMUL
Date:
Tue Feb 28 17:39:50 2017 +0000
Revision:
1:159a09ac60ba
Parent:
0:5ce3cfc57999
Child:
2:c31a1758ac38
First version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Manel_Marin 0:5ce3cfc57999 1 #include "mbed.h"
WilliamMarshQMUL 1:159a09ac60ba 2 #include "wdt.h"
Manel_Marin 0:5ce3cfc57999 3
WilliamMarshQMUL 1:159a09ac60ba 4 //WATCHDOG ENABLED (overloading library function SystemInit.c)
WilliamMarshQMUL 1:159a09ac60ba 5 //
WilliamMarshQMUL 1:159a09ac60ba 6 // The KL25Z watchdog is enabled after reset with timeout=1024ms (2^10*LPO=1KHz)
WilliamMarshQMUL 1:159a09ac60ba 7 // To make the dvice easy to use on mbed, th watchdog is disabled at startup
WilliamMarshQMUL 1:159a09ac60ba 8 // (in file SystemInit.c) **BUT** SIM_COPC register can only be written once
WilliamMarshQMUL 1:159a09ac60ba 9 // after reset and so it can not be enabled later. To resolve this,
WilliamMarshQMUL 1:159a09ac60ba 10 // SystemInit() is overloaded using: void $Sub$$SystemInit (void) {
Manel_Marin 0:5ce3cfc57999 11 //
WilliamMarshQMUL 1:159a09ac60ba 12 // The original SystemInit() can be dowloaded from:
WilliamMarshQMUL 1:159a09ac60ba 13 // https://developer.mbed.org/users/mbed_official/code/mbed-src/
WilliamMarshQMUL 1:159a09ac60ba 14 // navigating to ... targets/cmsis/TARGET_Freescale/TARGET_KLXX/
WilliamMarshQMUL 1:159a09ac60ba 15 // TARGET_KL25Z/system_MKL25Z4.c
WilliamMarshQMUL 1:159a09ac60ba 16 //
WilliamMarshQMUL 1:159a09ac60ba 17 // MORE on how this overides the original initialisation:
WilliamMarshQMUL 1:159a09ac60ba 18 // https://developer.mbed.org/users/chris/notebook/Patching-functions-and-libraries/
WilliamMarshQMUL 1:159a09ac60ba 19 // and searching "ARM Compiler toolchain Using the Linker"
WilliamMarshQMUL 1:159a09ac60ba 20 // "Using $Super$$ and $Sub$$ to patch symbol definitions"
Manel_Marin 0:5ce3cfc57999 21
Manel_Marin 0:5ce3cfc57999 22
Manel_Marin 0:5ce3cfc57999 23 #define LIGHT 0
Manel_Marin 0:5ce3cfc57999 24 #define DARK 1
Manel_Marin 0:5ce3cfc57999 25 DigitalOut led_red(LED_RED, LIGHT);
Manel_Marin 0:5ce3cfc57999 26 DigitalOut led_blue(LED_BLUE, DARK);
Manel_Marin 0:5ce3cfc57999 27
WilliamMarshQMUL 1:159a09ac60ba 28 // Demonstate the watchdog
WilliamMarshQMUL 1:159a09ac60ba 29 // The red LED is on after reset
WilliamMarshQMUL 1:159a09ac60ba 30 // Th blue LED flashes and the watch dog is fed
WilliamMarshQMUL 1:159a09ac60ba 31 // Aft 5sec, stop feeding the watchdog
WilliamMarshQMUL 1:159a09ac60ba 32 enum wState {Working, Stopped} ;
Manel_Marin 0:5ce3cfc57999 33
Manel_Marin 0:5ce3cfc57999 34 int main(void) {
WilliamMarshQMUL 1:159a09ac60ba 35 // initialise watchdog
WilliamMarshQMUL 1:159a09ac60ba 36 wdt_1sec() ;
WilliamMarshQMUL 1:159a09ac60ba 37
WilliamMarshQMUL 1:159a09ac60ba 38 // state of the watch dog
WilliamMarshQMUL 1:159a09ac60ba 39 wState watchDog = Working ;
WilliamMarshQMUL 1:159a09ac60ba 40 int counter = 10 ;
WilliamMarshQMUL 1:159a09ac60ba 41
WilliamMarshQMUL 1:159a09ac60ba 42 // show start-up
Manel_Marin 0:5ce3cfc57999 43 led_blue = DARK;
WilliamMarshQMUL 1:159a09ac60ba 44 led_red = LIGHT;
WilliamMarshQMUL 1:159a09ac60ba 45 wait(0.5) ;
Manel_Marin 0:5ce3cfc57999 46 led_red = DARK;
WilliamMarshQMUL 1:159a09ac60ba 47
WilliamMarshQMUL 1:159a09ac60ba 48 // Note: the red LED now stays OFF until processor reset
Manel_Marin 0:5ce3cfc57999 49 while(1)
Manel_Marin 0:5ce3cfc57999 50 {
Manel_Marin 0:5ce3cfc57999 51 led_blue = LIGHT;
WilliamMarshQMUL 1:159a09ac60ba 52 wait(0.25);
WilliamMarshQMUL 1:159a09ac60ba 53 if (watchDog == Working) wdt_kick_all() ;
Manel_Marin 0:5ce3cfc57999 54 led_blue = DARK;
WilliamMarshQMUL 1:159a09ac60ba 55 wait(0.25);
WilliamMarshQMUL 1:159a09ac60ba 56
WilliamMarshQMUL 1:159a09ac60ba 57 // When the counter rachs zero, chang state to stop watchdog
WilliamMarshQMUL 1:159a09ac60ba 58 if (counter > 0) counter-- ; else watchDog = Stopped ;
Manel_Marin 0:5ce3cfc57999 59 }
Manel_Marin 0:5ce3cfc57999 60 }