Blinky example works with timers, without delays

Author: matthiasbock

Makefile

@@ -35,16 +35,16 @@ CFLAGS += -I nordic/
 CFLAGS += -I sdk/
 
 // TODO: auto-detect chip revision
-CHIP_REVISION = ac
+CHIP_REVISION = aa
 
 LINKER_SCRIPT = linker/nrf51-blank-xx$(CHIP_REVISION).ld
 LDFLAGS += -T $(LINKER_SCRIPT)
 LDFLAGS += -L /usr/lib/gcc/arm-none-eabi/4.8/armv6-m/
 LDFLAGS += -L /usr/lib/arm-none-eabi/newlib/armv6-m/
-LDFLAGS += --start-group
-LDFLAGS += -lgcc
 LDFLAGS += -static
 LDFLAGS += -nostartfiles -nostdlib
+LDFLAGS += --start-group
+LDFLAGS += -lgcc
 
 
 #
@@ -56,7 +56,7 @@ all: demo_uart.elf demo_spi.elf demo_leds.elf demo_rgbstrip.elf demo_timers.elf
 demo_uart.elf: sdk/nrf51_startup.o nordic/system_nrf51.o sdk/strings.o sdk/fifo.o sdk/uart.o sdk/delay.o demo_uart.o 
 	$(LD) $(LDFLAGS) $^ -o $@
 
-demo_spi.elf: sdk/nrf51_startup.o nordic/system_nrf51.o sdk/strings.o sdk/fifo.o sdk/uart.o sdk/delay.o libad53x4/ad53x4.o libad53x4/demo_nrf51.o
+demo_spi.elf: sdk/nrf51_startup.o nordic/system_nrf51.o sdk/strings.o sdk/fifo.o sdk/uart.o sdk/delay.o libad53x4/ad53x4.o libad53x4/demo_ad53x4.o
 	$(LD) $(LDFLAGS) $^ -o $@	
 
 demo_leds.elf: sdk/nrf51_startup.o nordic/system_nrf51.o sdk/delay.o demo_leds.o

demo_timers.c

@@ -7,7 +7,7 @@
 #include "gpio.h"
 #include "timers.h"
 
-#define PIN_LED 20
+#define PIN_LED 28
 #define my_timer TIMER0
 
 void setup_led()
@@ -19,40 +19,66 @@ void setup_led()
 void setup_timer()
 {
     // reset timer
-    TIMER_TASK_STOP(my_timer) = 1;
+    TIMER_TASK_STOP(my_timer)  = 1;
     TIMER_TASK_CLEAR(my_timer) = 1;
 
     // configure 16MHz crystal frequency as clock source
     CLOCK_XTALFREQ = 0xFF;
 
     // start high frequency clock
     // (is that necessary?)
-    CLOCK_HFCLKSTAT = 1;
+    CLOCK_TASK_HFCLKSTART = 1;
+    while (!CLOCK_EVENT_HFCLKSTARTED)
+        asm("nop");
 
     // configure timer frequency
     TIMER_PRESCALER(my_timer) = 9;
 
     // configure timer mode
-    TIMER_MODE(my_timer)     = TIMER_MODE_TIMER;
-    TIMER_BITMODE(my_timer)  = TIMER_BITMODE_24BIT;
+//    TIMER_MODE(my_timer)       = TIMER_MODE_TIMER;
+//    TIMER_BITMODE(my_timer)    = TIMER_BITMODE_32BIT;
 
     // configure timer interrupt
-    TIMER_CC(my_timer)[0] = 0;
-    TIMER_INTENSET(my_timer) = TIMER_INTERRUPT_UPON_COMPARE(0);
+    TIMER_CC(my_timer)[0] = 0xffffffff;
+    TIMER_INTENSET(my_timer)  |= TIMER_INTERRUPT_UPON_COMPARE(0);
     interrupt_enable(TIMER0_INTERRUPT);
 
     // configure shortcut
+    /*
     TIMER_SHORTCUTS(my_timer) =
             TIMER_SHORTCUT_COMPARE_CLEAR(0)
           | TIMER_SHORTCUT_COMPARE_STOP(0);
+    */
 }
 
+bool led_on = false;
+uint32_t counter = 0;
+
 void TIMER0_Handler()
 {
-    // XOR with the mask for the chosen LED pin to toggle corresponding bit
-    GPIO_OUT = GPIO_OUT ^ (1 << PIN_LED);
+    TIMER_TASK_STOP(my_timer) = 1;
+    TIMER_TASK_CLEAR(my_timer) = 1;
+    TIMER_EVENT_COMPARE(my_timer)[0] = 0;
+
+    counter++;
+    if (counter >= 50000)
+    {
+        counter = 0;
+
+        if (led_on)
+        {
+            GPIO_OUT &= ~(1 << PIN_LED);
+            led_on = false;
+        }
+        else
+        {
+            GPIO_OUT |= 1 << PIN_LED;
+            led_on = true;
+        }
+    }
 
     // restart timer
+//    TIMER_CC(my_timer)[0] = 0x10000;
     TIMER_TASK_START(my_timer) = 1;
 }