avr/nano: i2c fixes
[ros_wild_thumper.git] / avr / nano / main.c
index aba8aa1..16a316c 100644 (file)
@@ -5,6 +5,9 @@
 #include <avr/interrupt.h>
 #include <avr/sleep.h>
 #include <util/delay.h>
+#include <util/twi.h>
+#include <avr/eeprom.h>
+#include <avr/wdt.h>
 #include "uart.h"
 
 /*
@@ -34,9 +37,9 @@
  */
 
 
-#define TWI_ACK                TWCR = (1<<TWEA) | (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
-#define TWI_RESET      TWCR &= ~((1 << TWSTO) | (1 << TWEN)); TWI_ACK
-#define TWI_NAK                TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
+#define TWI_ACK   TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWEN) | (1<<TWIE)
+#define TWI_NAK   TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWIE)
+#define TWI_RESET TWCR = (1<<TWINT) | (1<<TWEA) | (1<<TWSTO) | (1<<TWEN) | (1<<TWIE);
 
 static volatile uint8_t ireg=0;
 static volatile uint8_t bootloader=0;
@@ -55,13 +58,13 @@ ISR(TWI_vect)
 {
        static int16_t tmp16=0;
 
-       switch (TWSR & 0xF8)
+       switch(TW_STATUS)
        {  
-               case 0x60: // start write
+               case TW_SR_SLA_ACK: // start write
                        TWI_ACK;
                        ireg = 0;
                        break;
-               case 0x80: // write
+               case TW_SR_DATA_ACK: // write
                        switch(ireg) {
                                case 0x00: // register select
                                        ireg = TWDR;
@@ -80,8 +83,8 @@ ISR(TWI_vect)
                        }
                        ireg++;
                        break;
-               case 0xA8: // start read
-               case 0xB8: // read
+               case TW_ST_SLA_ACK: // start read
+               case TW_ST_DATA_ACK: // read
                        switch(ireg) {
                                case 0x01: // Distance left MSB
                                        tmp16 = dist_left;
@@ -170,6 +173,9 @@ ISR(TWI_vect)
                        }
                        ireg++;
                        break;
+               case TW_SR_STOP:
+                       TWI_ACK;
+                       break;
                default:
                        TWI_RESET;
        }
@@ -289,7 +295,7 @@ int main(void) {
 
        // I2C
        TWAR = 0x52;
-       TWI_RESET;
+       TWI_ACK;
 
        // Timer 1: Normal mode, Top: 0xffff, Prescaler: F_CPU/256=62500Hz
        TCCR1A = 0x0;
@@ -317,10 +323,11 @@ int main(void) {
                        case 0xff: // Magic reg that starts the bootloader
                                if (bootloader == 0xa5) {
                                        cli();
-                                       {
-                                               void (*start)(void) = (void*)0x1800;
-                                               start();
-                                       }
+                                       // write mark to first area in eeprom
+                                       eeprom_write_byte((uint8_t*)0, 123);
+                                       eeprom_busy_wait();
+                                       // Use watchdog to restart
+                                       wdt_enable(WDTO_15MS);
                                }
                                break;
                }