text: #pragma once
  
  #include "AP_HAL_Linux.h"
  #include <AP_ADC/AP_ADC.h>
  
  #include <fcntl.h>
  #include <unistd.h>
  
  #define IIO_ANALOG_IN_COUNT 8
  #define IIO_ANALOG_IN_DIR "/sys/bus/iio/devices/iio:device0/"
  
  #if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_PXF
  // Note that echo BB-ADC cape should be loaded
  #define IIO_VOLTAGE_SCALING 0.00142602816
  #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BBBMINI
  #define IIO_VOLTAGE_SCALING 3.0*1.8/4095.0
  #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_MINLURE
  #define IIO_VOLTAGE_SCALING 2.0 / 1000
  #else
  #define IIO_VOLTAGE_SCALING 1.0
  #endif
  
  class AnalogSource_IIO : public AP_HAL::AnalogSource {
  public:
      friend class AnalogIn_IIO;
      AnalogSource_IIO(int16_t pin, float initial_value, float voltage_scaling);
      float read_average();
      float read_latest();
      void set_pin(uint8_t p);
      void set_stop_pin(uint8_t p);
      void set_settle_time(uint16_t settle_time_ms);
      float voltage_average();
      float voltage_latest();
      float voltage_average_ratiometric() { return voltage_average(); }
  private:
      float       _value;
      float       _latest;
      float       _sum_value;
      float       _voltage_scaling;
      uint8_t     _sum_count;
      int16_t     _pin;
      int         _pin_fd;
      int         fd_analog_sources[IIO_ANALOG_IN_COUNT];
  
      void init_pins(void);
      void select_pin(void);
  
      static const char *analog_sources[];
  };
  
  class AnalogIn_IIO : public AP_HAL::AnalogIn {
  public:
      AnalogIn_IIO();
      void init();
      AP_HAL::AnalogSource* channel(int16_t n);
  
      // we don't yet know how to get the board voltage
      float board_voltage(void) { return 5.0f; }
  };
  