From 7f52e04004f9e6147790d674600e0eed5a5e8448 Mon Sep 17 00:00:00 2001
From: Michael Gernoth <michael@gernoth.net>
Date: Sun, 22 Aug 2010 18:31:35 +0200
Subject: [PATCH] working i2c connection to RSBS2-card

---
 bmc/Makefile | 10 +++++++---
 bmc/bmc.c    | 22 ++++++++++------------
 bmc/i2c.c    | 15 +++++++++------
 3 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/bmc/Makefile b/bmc/Makefile
index 8adc53d..6f8b4dd 100644
--- a/bmc/Makefile
+++ b/bmc/Makefile
@@ -1,9 +1,13 @@
-CC=avr-gcc
-CFLAGS=-mmcu=atmega16 -DF_CPU=8000000UL -Wall -g
-OBJCOPY=avr-objcopy
 PROG=dragon_jtag
 PORT=usb
 PMCU=m16
+GCCMCU=atmega16
+
+CPUFLAG=-mmcu=$(GCCMCU)
+CC=avr-gcc
+CFLAGS=$(CPUFLAG) -DF_CPU=8000000UL -Wall -g
+LDFLAGS=$(CPUFLAG)
+OBJCOPY=avr-objcopy
 
 all: bmc.bin
 
diff --git a/bmc/bmc.c b/bmc/bmc.c
index c786032..d7c5cdc 100644
--- a/bmc/bmc.c
+++ b/bmc/bmc.c
@@ -1,4 +1,5 @@
 #include <avr/io.h>
+#include <avr/sleep.h>
 #include <avr/interrupt.h>
 #include <stdio.h>
 #include "usart.h"
@@ -6,27 +7,24 @@
 
 int main(void)
 {
-	uint8_t pb = 0x00;
-	int8_t dir = 1;
-	volatile uint16_t i;
-
 	DDRB = 0xff;
+	PORTB = 0xff;
 
 	usart_init();
+	printf("\n");
+
 	i2c_init();
 
+	printf("Waiting for I2C...\n");
+
 	sei();
 
-	printf("Hallo!\n");
+	PORTB = 0xff;
 
 	while(1) {
-		pb += dir;
-		PORTB = pb;
-
-		for (i = 0; i < (pb<<5); i++) {}
-
-		if ((pb == 0) || (pb == 0xff))
-			dir = -dir;
+#if 1
+		sleep_mode();
+#endif
 	}
 
 	return 0;
diff --git a/bmc/i2c.c b/bmc/i2c.c
index 992d6ce..214d410 100644
--- a/bmc/i2c.c
+++ b/bmc/i2c.c
@@ -9,18 +9,21 @@
 
 void i2c_init()
 {
-	TWAR = BMC_ADDR;
-	TWCR &= ~(1<<TWSTA)|(1<<TWSTO);
-	TWCR|= (1<<TWEA) | (1<<TWEN)|(1<<TWIE); 
+	TWAR = BMC_ADDR & 0xfe;
+	TWDR = 0x00;
+	TWCR &= ~((1<<TWSTA) | (1<<TWSTO));
+	TWCR |= ((1<<TWEA) | (1<<TWEN) | (1<<TWIE)); 
+	printf("Status: 0x%02x\n", TW_STATUS);
+	PORTC = 0x03;
 }
 
-ISR (TWI_vect)
+ISR (TWI_vect, ISR_BLOCK)
 {
-	printf("Interrupt, Status: %02x!\n", TW_STATUS);
+	printf("Interrupt, Status: 0x%02x, Data: 0x%02x!\n", TW_STATUS, TWDR);
 
 	switch (TW_STATUS) {
 		default:
-			TWCR_RESET;
+			TWCR_ACK;
 			break;
 	}
 }
-- 
2.39.2