manual i2c id bit communication

src/main.c

@@ -3,7 +3,6 @@
  * See LICENSE for details.
  */
 
-#define F_CPU 16000000UL
 #define BAUD 9600
 
 #include <avr/io.h>
@@ -11,6 +10,7 @@
 #include <util/setbaud.h>
 
 #include "bme280.h"
+#include "i2c.h"
 #include <stdio.h>
 
 
@@ -35,8 +35,16 @@ void uart_putchar(char c) {
     UDR0 = c;
 }
 
+void uart_putstr(const char *str) {
+    while(*str) {
+        uart_putchar(*str++);
+    }
+}
+
 int main(void)
 {
+    uart_init();
+
     // make the LED pin an output for PORTB5
     DDRB = 1 << 5;
 
@@ -44,20 +52,26 @@ int main(void)
     float pressure = 0.0;
     float humidity = 0.0;
 
-    bme280_init(0);
+    _delay_ms(500);
+    i2c_init();
+    i2c_start((0x76 << 1) | 0x00);
+    i2c_byte(0xD0);
+    i2c_stop();
 
-    temp = bme280_readTemperature(0);
-    pressure = bme280_readPressure(0);
-    humidity = bme280_readHumidity(0);
+    _delay_us(10);
+    i2c_start((0x76 << 1) | 0x01);
+    uint8_t ret = i2c_readAck();
+    i2c_stop();
+
+    if(ret == 0x60) { uart_putstr("\nbme280 detected.\n"); }
+    //temp = bme280_readTemperature(0);
+    //pressure = bme280_readPressure(0);
+    //humidity = bme280_readHumidity(0);
 
-    uart_init();
 
     while (1)
     {
         _delay_ms(1000);
-        uart_putchar('!');
-
-        //printf("Temp: %f\tPressure: %f\tHumidity: %f\n", temp, pressure, humidity);
 
         // toggle the LED
         PORTB ^= 1 << 5;