adc early

build.sh

@@ -13,7 +13,7 @@ else
 		-DARDUINO=10607 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR \
 		-I/usr/avr/include \
 		-I/usr/lib/avr/include \
-		../include/uart.c main.c -o $BUILD/main.elf
+		../include/uart.c ../include/rand.c ../include/adc.c main.c -o $BUILD/main.elf
 
 	avr-objcopy -O ihex -R .eeprom $BUILD/main.elf $BUILD/main.hex
 

include/adc.c

@@ -0,0 +1,18 @@
+#include "adc.h"
+#include <stdint.h>
+#include <avr/interrupt.h>
+#include <avr/io.h>
+#include <util/delay.h>
+
+void adc_init() {
+	//DDRA=0x0; // does not exist but is default?
+	ADCSRA = (1<<ADEN)|(1<<ADPS1)|(1<<ADPS2);
+	ADMUX = (1<<REFS0);
+}
+uint16_t adc_read(uint8_t channel) {
+    ADMUX &= 0xf0;
+    ADMUX |= (channel & 0x0f);
+    ADCSRA |= (1<<ADSC);
+    while((ADCSRA&(1<<ADIF))==0);
+    return ADCL + (ADCH << 8);
+}

include/adc.h

@@ -0,0 +1,6 @@
+#pragma once
+#define F_CPU 16000000UL
+#define __AVR_ATmega328P__
+#include <stdio.h>
+void adc_init();
+uint16_t adc_read(uint8_t channel);

include/rand.c

@@ -0,0 +1,13 @@
+int rand() {
+    static unsigned int seed = 1337191337;
+    unsigned int buf[] = {
+        (seed*31832)%677,
+        (seed*32932)%2332
+    };
+    seed = buf[1]*223238;
+    seed *= seed << 4;
+    seed %= 410829;
+    seed = buf[0] * 1892823 % 23891;
+    seed = buf[0];
+    return seed;
+}

include/rand.h

@@ -0,0 +1,2 @@
+#pragma once
+unsigned int rand(void);

print/main.c

@@ -4,6 +4,8 @@
 #include <avr/io.h>
 #include <util/delay.h>
 #include "../include/uart.h"
+#include "../include/adc.h"
+#include "../include/rand.h"
 
 #define BAUD 9600
 #define MYUBRR F_CPU/16/BAUD-1
@@ -15,14 +17,16 @@ int main (void)
     sei();
 
     char buf[10];
-    int sensor;
+    int sensor[2];
 
     while (1)
     {
         // lets say we read some value from a sensor
-        sensor = 65;
+        sensor[0] = adc_read(0);
+        sensor[1] = adc_read(1);
         // we want to print this, so we store the ascii repr in our buffer
-        uart_printi("sensor status: ", sensor);
+        uart_printi("sensor 0: ", sensor[0]);
+        uart_printi("sensor 1: ", sensor[1]);
         _delay_ms(1000);
     }
 }