ardupilot/libraries/AP_HAL_AVR/AnalogIn.h

72 lines
2.1 KiB
C++

#ifndef __AP_HAL_AVR_ANALOG_IN_H__
#define __AP_HAL_AVR_ANALOG_IN_H__
#include <AP_HAL.h>
#include "AP_HAL_AVR_Namespace.h"
#define AVR_INPUT_MAX_CHANNELS 12
class AP_HAL_AVR::ADCSource : public AP_HAL::AnalogSource {
public:
friend class AP_HAL_AVR::AVRAnalogIn;
/* pin designates the ADC input number, or when == AVR_ANALOG_PIN_VCC,
* board vcc */
ADCSource(uint8_t pin, float prescale = 1.0);
/* implement AnalogSource virtual api: */
float read_average();
float read_latest();
void set_pin(uint8_t p);
/* implementation specific interface: */
/* new_sample(): called with value of ADC measurments, from interrput */
void new_sample(uint16_t);
/* setup_read(): called to setup ADC registers for next measurment,
* from interrupt */
void setup_read();
/* read_average: called to calculate and clear the internal average.
* implements read_average(), unscaled. */
float _read_average();
int16_t get_pin() { return _pin; };
private:
/* following three are used from both an interrupt and normal thread */
volatile uint8_t _sum_count;
volatile uint16_t _sum;
volatile uint16_t _latest;
/* _pin designates the ADC input mux for the sample */
uint8_t _pin;
/* prescale scales the raw measurments for read()*/
const float _prescale;
};
/* AVRAnalogIn : a concrete class providing the implementations of the
* timer event and the AP_HAL::AnalogIn interface */
class AP_HAL_AVR::AVRAnalogIn : public AP_HAL::AnalogIn {
public:
AVRAnalogIn();
void init(void* ap_hal_scheduler);
AP_HAL::AnalogSource* channel(int16_t n);
AP_HAL::AnalogSource* channel(int16_t n, float prescale);
protected:
static ADCSource* _find_or_create_channel(int16_t num, float scale);
static ADCSource* _create_channel(int16_t num, float scale);
static void _register_channel(ADCSource*);
static void _timer_event(uint32_t);
static ADCSource* _channels[AVR_INPUT_MAX_CHANNELS];
static int16_t _num_channels;
static int16_t _active_channel;
static int16_t _channel_repeat_count;
private:
ADCSource _vcc;
};
#endif // __AP_HAL_AVR_ANALOG_IN_H__