Enabled the internal pull-ups for the I2C pins.

Removed any write to the I2C pins to avoid communication errors.

gpio.c

@@ -14,7 +14,7 @@ void InitGPIO(void)
 	 			   // Pc3 as an input (OVP)
     
 
-    PORTC=0x00;
+    PORTC=PORTC&0xF0;
 }
 
 void enable_battery(void)

i2c.c

@@ -51,8 +51,8 @@ void i2cInit(void)
 {
 	// set pull-up resistors on I2C bus pins
 	// TODO: should #ifdef these
-//	sbi(PORTC, 5);	// i2c SCL on ATmega163,323,16,32,etc
-//	sbi(PORTC, 4);	// i2c SDA on ATmega163,323,16,32,etc
+	sbi(PORTC, 5);	// i2c SCL on ATmega163,323,16,32,etc
+	sbi(PORTC, 4);	// i2c SDA on ATmega163,323,16,32,etc
 //	sbi(PORTD, 0);	// i2c SCL on ATmega128,64
 //	sbi(PORTD, 1);	// i2c SDA on ATmega128,64
 

tibi_dabo_battery.c

@@ -41,6 +41,7 @@ int main (void)
 
    // initialize the GPIO
    InitGPIO();
+   
    // initialize uart
    uartInit();
    // set desired baud rate in bps