From 68e463ad5c3b0225dbf293ac609b3b7784fe0a0b Mon Sep 17 00:00:00 2001
From: Leo C <erbl259-lmu@yahoo.de>
Date: Fri, 5 Sep 2014 12:46:19 +0200
Subject: [PATCH] Use timer2 as 1ms sytem clock (instead timer1).

---
 avr/main.c  | 11 ++++++-----
 avr/timer.c | 17 +++++++++--------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/avr/main.c b/avr/main.c
index e4c98b8..65622cc 100644
--- a/avr/main.c
+++ b/avr/main.c
@@ -77,8 +77,8 @@ void setup_avr(void)
 	MCUCR = _BV(JTD);
 	MCUCR = _BV(JTD);
 
-	/* disable unused periphels */
-	PRR0 = _BV(PRTIM2) | _BV(PRTIM0) | _BV(PRADC);
+	/* disable unused peripherals */
+	PRR0 = _BV(PRTIM0) | _BV(PRADC);
 	PRR1 = _BV(PRTIM5) | _BV(PRTIM4) | _BV(PRTIM3) |
 		_BV(PRUSART3) | _BV(PRUSART2) | _BV(PRUSART1);
 
@@ -92,9 +92,10 @@ void setup_avr(void)
 
 	/* Timer */
 
-	OCR1A = F_CPU / 8 / 1000 - 1; // Timer1: 1000Hz interval (OC1A)
-	TCCR1B = 0b00001010;
-	TIMSK1 = _BV(OCIE1A); // Enable TC1.oca interrupt
+	OCR2A = F_CPU / 256 / 1000 - 1; /* Timer2: 1000Hz interval (OC2A) */
+	TCCR2A = (0b10 << WGM20);	/* CTC Mode */
+	TCCR2B = (0b110 << CS20);	/* Prescaler 256 */
+	TIMSK2 = _BV(OCIE2A);		/* Enable TC2.oca interrupt */
 }
 
 static
diff --git a/avr/timer.c b/avr/timer.c
index 84a9737..56c7bed 100644
--- a/avr/timer.c
+++ b/avr/timer.c
@@ -15,14 +15,14 @@
 #include "timer.h"
 
 /* timer interrupt/overflow counter */
-static volatile uint32_t timestamp;
+volatile uint32_t timestamp;
 
 
 /*---------------------------------------------------------*/
-/* 1000Hz timer interrupt generated by OC1A                 */
+/* 1000Hz timer interrupt generated by OC2A                */
 /*---------------------------------------------------------*/
 
-ISR(TIMER1_COMPA_vect)
+ISR(TIMER2_COMPA_vect)
 {
 	static int_fast8_t tick_10ms;
 	int_fast8_t i;
@@ -34,12 +34,12 @@ ISR(TIMER1_COMPA_vect)
 	if (i == 10) {
 		i = 0;
 		Stat |= S_10MS_TO;
-		
+
 		/* Drive timer procedure of low level disk I/O module */
 		//disk_timerproc();
 	}
 	tick_10ms = i;
-	
+
 }
 
 
@@ -48,7 +48,7 @@ ISR(TIMER1_COMPA_vect)
 
 #if 0
 
-void do_10ms(void) 
+void do_10ms(void)
 {
 		if (to_counter)
 			to_counter--;
@@ -59,6 +59,7 @@ void do_10ms(void)
 /*--------------------------------------------------------------------------*/
 
 
+#if 0
 void timer_setup(void)
 {
 
@@ -72,12 +73,12 @@ void timer_setup(void)
 	TCCR1B = 0b00001001;
 	TIMSK1 = _BV(OCIE1A); // Enable TC1.oca interrupt
 }
-
+#endif
 
 uint32_t get_timer(uint32_t base)
 {
 	uint32_t ret;
-	
+
 	ATOMIC_BLOCK(ATOMIC_FORCEON)
 	{
 		ret = timestamp;
-- 
2.39.2