osd-contiki/platform/RaspBee/dev/adc.h

66 lines
1.5 KiB
C
Raw Permalink Normal View History

#ifndef __ADC_ARCH_H__
#define __ADC_ARCH_H__
#include <avr/io.h>
/*
* Reference voltage
* The default is 1.6V reference voltage
* The selected reference voltage is the maximum voltage that can be
* measured.
* Directly provide shifted variants so we don't need to shift.
*/
#define ADC_1_5 (2<<6)
#define ADC_1_6 (3<<6)
#define ADC_1_8 (1<<6)
#define ADC_EXTERNAL (0<<6)
#define ADC_DEFAULT ADC_1_6
/* sometimes it's desirable to decouple setup / finish from sampling */
static inline void adc_setup (uint8_t ref_volt, uint8_t pin)
{
ADMUX = ref_volt | (pin & 0x7);
ADCSRA = _BV(ADEN) | _BV(ADPS0) | _BV(ADPS2);
}
static inline int adc_read (void)
{
ADCSRA |= (1 << ADSC);
loop_until_bit_is_clear (ADCSRA, ADSC);
return ADC;
}
static inline void adc_fin (void)
{
ADCSRA = 0;
ADMUX = 0;
}
static inline void adc_init (void)
{
uint8_t temp;
ADCSRC = 0;
ADCSRB = 0;
adc_fin ();
/*
* Disable JTAG interface
* Hardware manual about JTD bit:
* "In order to avoid unintentional disabling or enabling of the
* JTAG interface, a timed sequence must be followed when changing
* this bit: The application software must write this bit to the
* desired value twice within four cycles to change its value."
* 15.4.1 "MCUCR - MCU Control Register", p. 219
*/
temp = MCUCR | (1 << JTD);
MCUCR = temp;
MCUCR = temp;
}
int readADC(uint8_t pin);
long readVcc();
int readInternalTemp(void);
void analogReference(uint8_t mode);
#endif /* __ADC_ARCH_H__ */