David Bottrill / Mbed 2 deprecated Watchdog

Are you frustrated that the KL25Z watchdog timer refuses to work? This programme offers an alternate approach using a ticker interrupt to monitor the main loop and generate a hardware reset if the software controlled output pin is connected to the reset pin.

Dependencies:   mbed

main.cpp@0:9498eae934ed, 2014-02-01 (annotated)

Committer:
djbottrill
Date:
Sat Feb 01 01:03:05 2014 +0000
Revision:
0:9498eae934ed
Child:
1:bac7ddc3679a
Doesn't work on KL25Z

Who changed what in which revision?

UserRevisionLine numberNew contents of line
djbottrill 0:9498eae934ed 1 #include "mbed.h"
djbottrill 0:9498eae934ed 2
djbottrill 0:9498eae934ed 3 //DigitalOut led(LED1);
djbottrill 0:9498eae934ed 4 DigitalOut blueled (LED_BLUE);
djbottrill 0:9498eae934ed 5 DigitalOut greenled (LED_GREEN);
djbottrill 0:9498eae934ed 6 DigitalOut redled (LED_RED);
djbottrill 0:9498eae934ed 7
djbottrill 0:9498eae934ed 8 Serial pc(USBTX,USBRX);
djbottrill 0:9498eae934ed 9
djbottrill 0:9498eae934ed 10
djbottrill 0:9498eae934ed 11 int main() {
djbottrill 0:9498eae934ed 12 blueled = 1; // Off
djbottrill 0:9498eae934ed 13 greenled = 1; // Off
djbottrill 0:9498eae934ed 14 redled = 1; // Off
djbottrill 0:9498eae934ed 15
djbottrill 0:9498eae934ed 16 SIM->COPC= 0x0C; // Initialise Watchdog for 2^10 cycles of 1 KHz LPO clock ~ 1 second
djbottrill 0:9498eae934ed 17 // Use the Macro in 'MKL25Z4.h' to write to the COPC options field
djbottrill 0:9498eae934ed 18 // https://mbed.org/users/mbed_official/code/mbed-Freescale/file/3a8b2b3870fb/cmsis/KL25Z/MKL25Z4.h
djbottrill 0:9498eae934ed 19 // SIM_COPC_COPT(0x0C); // Initialise Watchdog for 2^10 cycles of 1 KHz LPO clock ~ 1 second
djbottrill 0:9498eae934ed 20
djbottrill 0:9498eae934ed 21 blueled = 0; // turn on blue BEFORE we test comms
djbottrill 0:9498eae934ed 22 pc.printf("Hello World!\r\n");// Show that the code has started running at the beginning
djbottrill 0:9498eae934ed 23 blueled = 1; // turn off Blue
djbottrill 0:9498eae934ed 24 greenled = 0; // turn on Green AFTER we tested comms
djbottrill 0:9498eae934ed 25
djbottrill 0:9498eae934ed 26 int iHang = 0; // Initialise our loop counter to Zero
djbottrill 0:9498eae934ed 27
djbottrill 0:9498eae934ed 28 while(1) { // The start of the 'forever' main loop
djbottrill 0:9498eae934ed 29 pc.printf("loop %d\r\n", iHang); // Show that we are looping
djbottrill 0:9498eae934ed 30 wait(0.1); // wait .1 second
djbottrill 0:9498eae934ed 31 blueled = 0; // turn on blue (as well as green) while we loop
djbottrill 0:9498eae934ed 32
djbottrill 0:9498eae934ed 33 SIM->SRVCOP = 0x55; // refresh the Watchdog to stop it resetting us
djbottrill 0:9498eae934ed 34 SIM->SRVCOP = 0xAA;
djbottrill 0:9498eae934ed 35 // Use the Macro in 'MKL25Z4.h' to write to the SRVCOP data field
djbottrill 0:9498eae934ed 36 // https://mbed.org/users/mbed_official/code/mbed-Freescale/file/3a8b2b3870fb/cmsis/KL25Z/MKL25Z4.h
djbottrill 0:9498eae934ed 37 // SIM_SRVCOP_SRVCOP(0x55);// refresh the Watchdog to stop it resetting us
djbottrill 0:9498eae934ed 38 // SIM_SRVCOP_SRVCOP(0xAA);
djbottrill 0:9498eae934ed 39
djbottrill 0:9498eae934ed 40 iHang++; // Count the number of times we have prevented a reboot
djbottrill 0:9498eae934ed 41
djbottrill 0:9498eae934ed 42 if(iHang == 10) { // after 10 times round the loop...
djbottrill 0:9498eae934ed 43 blueled = 1; // turn off Blue
djbottrill 0:9498eae934ed 44 greenled = 1; // turn off Green
djbottrill 0:9498eae934ed 45 redled = 0; // turn on Red
djbottrill 0:9498eae934ed 46 while(1) ; // Stall the program until the watchdog resets the micro'
djbottrill 0:9498eae934ed 47 }
djbottrill 0:9498eae934ed 48
djbottrill 0:9498eae934ed 49 } // End of 'forever' loop
djbottrill 0:9498eae934ed 50 }