Diff: main.cpp

Revision:

0:5ce3cfc57999

Child:

1:159a09ac60ba

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Nov 21 13:24:29 2015 +0000
@@ -0,0 +1,52 @@
+#include "mbed.h"
+
+//WATHDOG ENABLED IN OUR KL25Z_SystemInit.c (overloading library function SystemInit.c)
+// It happens in this uC after reset watchdog is enabled with timeout=1024ms (2^10*LPO=1KHz)
+//  so mbed developers to allow a learning use of this board disable it on SystemInit.c
+// **BUT** SIM_COPC register can only be written once after reset and so it can not be enabled later
+//  I think best solution is to overload SystemInit() using:   void $Sub$$SystemInit (void) {
+//  original SystemInit() does not appear in export, it must be dowloaded from:
+// https://developer.mbed.org/users/mbed_official/code/mbed-src/file/a11c0372f0ba/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/system_MKL25Z4.c
+//  you can arrive there from:
+// https://developer.mbed.org/handbook/mbed-SDK and https://developer.mbed.org/users/mbed_official/code/mbed-src/
+//
+// MORE on this on: https://developer.mbed.org/users/chris/notebook/Patching-functions-and-libraries/
+// and searching "ARM Compiler toolchain Using the Linker" "Using $Super$$ and $Sub$$ to patch symbol definitions"
+
+// Kick (feed, reload) our watchdog timer
+void wdt_kick(){
+    SIM->SRVCOP = (uint32_t)0x55u;
+    SIM->SRVCOP = (uint32_t)0xAAu;
+}
+
+// That set RED LED ON, do that first to evaluate boot time of peripherals
+#define LIGHT 0
+#define DARK 1
+DigitalOut led_red(LED_RED, LIGHT);
+DigitalOut led_green(LED_GREEN, DARK);
+DigitalOut led_blue(LED_BLUE, DARK);
+
+//Virtual serial port over USB using inboard second USB connector (USBKL25Z port)
+#include "USBSerial.h"
+//USBSerial pc;
+//...( vendor_id, product_id, product_release, connect_blocking )
+USBSerial pc( 0x1f00, 0x2012, 0x0001, false );
+//REMEMBER TO USE: class USBSerial -> connect_blocking = false (default is true)
+//  to avoid block of program when no USB cable connected in USBKL25Z port
+//NOTE: USBSerial still blocks program when closing serial terminal, that is fixed by our watchdog
+
+
+int main(void) {
+    //to evaluate boot time I set led RED ON at the beginning of our main.cpp. TODO?: do it in SystemInit?
+    led_blue = DARK;
+    led_green = DARK;
+    led_red = DARK;
+    while(1)
+    {
+        led_blue = LIGHT;
+        pc.printf("I am a virtual serial port\r\n");    // THAT COULD BLOCK
+        wdt_kick();
+        led_blue = DARK;
+        wait(0.5);
+    }
+}
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