Init

adc.c

@@ -0,0 +1,43 @@
+
+/*
+ * Copyright 2017-2024 Oleg Borodin <onborodin@gmail.com>
+ */
+
+#include <avr/interrupt.h>
+#include <util/delay.h>
+
+#include <tool.h>
+
+void adc_init() {
+    /* Disable ADC */
+    REG_SETDOWN_BIT(ADCSRA, ADEN);
+    /* Set reference*/
+    REG_SETUP_BIT(ADMUX, REFS0);
+    REG_SETDOWN_BIT(ADMUX, REFS1);
+    /* Set result type */
+    REG_SETUP_BIT(ADMUX, ADLAR);
+    /* Set freq prescale */
+    REG_SETUP_BIT(ADCSRA, ADPS2);
+    REG_SETUP_BIT(ADCSRA, ADPS1);
+    REG_SETUP_BIT(ADCSRA, ADPS0);
+    /* Disable autoconversion */
+    REG_SETDOWN_BIT(ADCSRA, ADATE);
+    /* Disable interrupt */
+    REG_SETDOWN_BIT(ADCSRA, ADIE);
+    /* Enable ADC */
+    REG_SETUP_BIT(ADCSRA, ADEN);
+}
+
+uint16_t adc_read(uint8_t channel) {
+    uint8_t reg = ADMUX;
+    ADMUX = (reg & 0xF0) | channel;
+    REG_SETUP_BIT(ADCSRA, ADSC);
+    while (ADCSRA & BIT(ADSC));
+    uint16_t lval = (uint16_t)ADCL;
+    uint16_t hval = (uint16_t)ADCH;
+    hval = (hval << 8) & 0xFF00;
+    lval = lval & 0x00FF;
+    return (hval | lval);
+}
+
+