ApogeeSQ212.h file

Classes

class ApogeeSQ212

The Sensor sub-class for the Apogee SQ-212 sensor.

class ApogeeSQ212_PAR

The Variable sub-class used for the photosynthetically active radiation (PAR) output from an Apogee SQ-212.

class ApogeeSQ212_Voltage

The Variable sub-class used for the raw voltage output from an Apogee SQ-212.

Defines

#define SQ212_NUM_VARIABLES = 2

Sensor::_numReturnedValues; the SQ212 can report 2 values, raw voltage and calculated PAR.

#define SQ212_INC_CALC_VARIABLES = 1

Sensor::_incCalcValues; PAR is calculated from the raw voltage.

#define SQ212_CALIBRATION_FACTOR = 1

The calibration factor between output in volts and PAR (microeinsteinPerSquareMeterPerSecond) 1 µmol mˉ² sˉ¹ per mV (reciprocal of sensitivity)

#define ADS1115_ADDRESS = 0x48

The assumed address of the ADS1115, 1001 000 (ADDR = GND)

Sensor Timing

The sensor timing for an Apogee SQ-212

#define SQ212_WARM_UP_TIME_MS = 2

Sensor::_warmUpTime_ms; the warm up time is unknown; using the 2ms for the TI ADS1x15 to warm up.

#define SQ212_STABILIZATION_TIME_MS = 2

Sensor::_stabilizationTime_ms; the ADS1115 is stable after 2ms.

#define SQ212_MEASUREMENT_TIME_MS = 2

Sensor::_measurementTime_ms; ADS1115 takes almost 2ms to complete a measurement (860/sec).

PAR

The PAR variable from an Apogee SQ-212

• Range is 0 to 2500 µmol m-2 s-1
• Accuracy is ± 0.5%
• Resolution:
  • 16-bit ADC (ADS1115): 0.3125 µmol m-2 s-1 (ADS1115)
  • 12-bit ADC (ADS1015, using build flag MS_USE_ADS1015): 5 µmol m-2 s-1 (ADS1015)
• Reported as microeinsteins per square meter per second (µE m-2 s-1 or µmol m-2 s-1)

{{ ApogeeSQ212_PAR }}

#define SQ212_PAR_VAR_NUM = 0

Variable number; PAR is stored in sensorValues[0].

#define SQ212_PAR_VAR_NAME = "radiationIncomingPAR"

Variable name in ODM2 controlled vocabulary; "radiationIncomingPAR".

#define SQ212_PAR_UNIT_NAME = "microeinsteinPerSquareMeterPerSecond"

Variable unit name in ODM2 controlled vocabulary; "microeinsteinPerSquareMeterPerSecond" (µE m-2 s-1 or µmol * m-2 s-1)

#define SQ212_PAR_DEFAULT_CODE = "photosyntheticallyActiveRadiation"

Default variable short code; "photosyntheticallyActiveRadiation".

#define SQ212_PAR_RESOLUTION = 4

Decimals places in string representation; PAR should have 4 when using an ADS1115.

Voltage

The voltage variable from an Apogee SQ-212

• Range is 0 to 3.6V [when ADC is powered at 3.3V]
• Accuracy is ± 0.5%
  • 16-bit ADC (ADS1115): < 0.25% (gain error), <0.25 LSB (offset error)
  • 12-bit ADC (ADS1015, using build flag MS_USE_ADS1015): < 0.15% (gain error), <3 LSB (offset error)
• Resolution [assuming the ADC is powered at 3.3V with inbuilt gain set to 1 (0-4.096V)]:
  • 16-bit ADC (ADS1115): 0.125 mV (ADS1115)
  • 12-bit ADC (ADS1015, using build flag MS_USE_ADS1015): 2 mV (ADS1015)

{{ ApogeeSQ212_Voltage }}

#define SQ212_VOLTAGE_VAR_NUM = 1

Variable number; voltage is stored in sensorValues[1].

#define SQ212_VOLTAGE_VAR_NAME = "voltage"

Variable name in ODM2 controlled vocabulary; "voltage".

#define SQ212_VOLTAGE_UNIT_NAME = "volt"

Variable unit name in ODM2 controlled vocabulary; "volt" (V)

#define SQ212_VOLTAGE_DEFAULT_CODE = "SQ212Voltage"

Default variable short code; "SQ212Voltage".

#define SQ212_VOLTAGE_RESOLUTION = 4

Decimals places in string representation; voltage should have 4 when used with an ADS1115.