Analog Example

The supported Analog Sensor Output Types are:

1. 4-20mA
2. 0-10V.

This example will supply power to an Analog sensor, read the current (in uA ) OR voltage (in mV) level at the EXT_ANALOG_IN pin and print the value on the debug console.

 
#include <stdio.h>
#include "flex.h"
 
#define APPLICATION_NAME "Analog Example"
 
// Note: Set this to 0 if the Analog Sensor Output Type is 0-10V, and
// set this to 1 if the Analog Sensor Output Type is 4-20mA.
#define MEASURE_CURRENT 1
 
#if MEASURE_CURRENT
#define ANALOG_IN_MODE FLEX_ANALOG_IN_CURRENT
#define APPLICATION_MODE "current"
#else
#define ANALOG_IN_MODE FLEX_ANALOG_IN_VOLTAGE
#define APPLICATION_MODE "voltage"
#endif
 
// The number of sensor readings a day.
// Modify this as required by the application.
#define SENSOR_READINGS_PER_DAY 4
 
// Modify this according to the power requirements of the Analog sensor.
// The FlexSense board supports an output voltage given by the enum FLEX_PowerOut.
#define ANALOG_SENSOR_POWER_IN FLEX_POWER_OUT_24V
 
// Modify this delay to save power based on the sensor stabilisation time
#define DELAY_SENSOR_STABILISE_MS 1500
 
static uint32_t MeasureAnalogInput(void) {
  uint32_t SensorReading = UINT32_MAX;
 
  if (FLEX_PowerOutInit(ANALOG_SENSOR_POWER_IN) != 0) {
    printf("Failed to Init Power Out.\r\n");
    goto fail_0;
  }
 
  if (FLEX_AnalogInputInit(ANALOG_IN_MODE) != 0) {
    printf("Failed to Init Analog Input.\r\n");
    goto fail_1;
  }
 
  FLEX_DelayMs(DELAY_SENSOR_STABILISE_MS);
 
#if MEASURE_CURRENT
  if (FLEX_AnalogInputReadCurrent(&SensorReading) != 0) {
    printf("Failed to Read Current.\r\n");
  }
#else
  if (FLEX_AnalogInputReadVoltage(&SensorReading) != 0) {
    printf("Failed to Read Voltage.\r\n");
  }
#endif
 
  // De-initialise the Analog Input for the lowest idle power consumption.
  FLEX_AnalogInputDeinit();
fail_1:
  // De-initialise the Power Out interface for the lowest idle power consumption.
  FLEX_PowerOutDeinit();
fail_0:
  return SensorReading;
}
 
static time_t PrintSensorReading(void) {
  uint32_t analog_sensor_reading = MeasureAnalogInput();
 
  if (analog_sensor_reading != UINT32_MAX) {
#if MEASURE_CURRENT
    printf("Current = %luuA.\r\n", analog_sensor_reading);
#else
    printf("Voltage = %lumV.\r\n", analog_sensor_reading);
#endif
  }
 
  return (FLEX_TimeGet() + 24 * 3600 / SENSOR_READINGS_PER_DAY);
}
 
void FLEX_AppInit() {
  printf("%s (%s mode).\r\n", APPLICATION_NAME, APPLICATION_MODE);
  FLEX_JobSchedule(PrintSensorReading, FLEX_ASAP());
}