Adding the avr-rss2 platform based on AtMega256RFR2

platform/avr-rss2/dev/adc.c

@@ -0,0 +1,76 @@
+/* Copyright Robert Olsson */
+
+#include <avr/pgmspace.h>
+#include <avr/fuse.h>
+#include <avr/eeprom.h>
+#include <stdio.h>
+#include <string.h>
+#include <dev/watchdog.h>
+#include "params.h"
+#include "rss2.h"
+#include "contiki.h"
+#include "adc.h"
+#include "rss2.h"
+
+uint16_t
+adc_read(uint8_t pin)
+{
+  uint16_t volt = 0;
+  int i;
+
+  ADMUX = pin; /* ADC pin PA0-PA7 ->  0-7 */
+  ADCSRB &= ~(1 << MUX5); /* Needs to write before ADMUX pp 418 */
+  ADMUX |= (1 << REFS1) | (1 << REFS0); /* 1.6 */
+
+  /* Maximal Track and Hold time */
+
+  ADCSRA = (1 << ADPS2) | (0 << ADPS1) | (1 << ADPS0);  /* Prescaler /32 */
+  ADCSRA |= (1 << ADEN);  /* Enable the ADC */
+
+  while(!(ADCSRB & (1 << AVDDOK))) ;  /* Wait for AVDD ok */
+  while(!(ADCSRB & (1 << REFOK))) ;  /* Wait for ref ok  */
+
+  /* Ignore first result */
+
+  ADCSRA |= (1 << ADSC);
+  while(ADCSRA & _BV(ADSC)) {
+  }
+
+  ADCW = 0;
+#define RES 4
+
+  for(i = 0; i < RES; i++) {
+
+    /* Start the conversion */
+    ADCSRA |= (1 << ADSC);
+
+    /* Wait for conversion */
+    while(ADCSRA & (1 << ADSC)) {
+    }
+
+    volt += ADCW;
+  }
+  ADMUX = 0;                /* turn off internal vref */
+  volt = volt / RES;
+
+  /* Disable the ADC to save power */
+  ADCSRA &= ~_BV(ADEN);
+
+  return volt;
+}
+double
+adc_read_v_in(void)
+{
+  /* Special treatment for v_in. Schottky voltage drop add */
+  return ((double)adc_read(AV_IN)) * V_IN_FACTOR_SCHOTTKY + SCHOTTKY_DROP;
+}
+double
+adc_read_a1(void)
+{
+  return ((double)adc_read(A1)) * V_IN_FACTOR;
+}
+double
+adc_read_a2(void)
+{
+  return ((double)adc_read(A2)) * V_IN_FACTOR;
+}