Zebra-Tech D-Opto module

Introduction

The Zebra-Tech D-Opto sensor is implemented as a sub-classes of the SDI12Sensors class. It requires an 8-12V power supply, which can be turned off between measurements. The connection between the logger and the Arduino board is made by way of a white interface module provided by Zebra-Tech. You will need a voltage booster or a separate power supply to give the D-Opto sufficient voltage to run. At the Stroud Center, we use Pololu 9V Step-Up Voltage Regulators.

Sensor Datasheet

The manual for this sensor is available at: www.zebra-tech.co.nz/wp-content/uploads/2014/04/D-Opto-Sensor-manual-A4-ver-2.pdf

Build flags

Sensor Constructor

Example Code

The Zebra-Tech D-Opto is used in the menu a la carte example.

#include <sensors/ZebraTechDOpto.h>

// NOTE: Use -1 for any pins that don't apply or aren't being used.
const char*  DOptoSDI12address = "5";  // The SDI-12 Address of the D-Opto
const int8_t ZTPower           = sensorPowerPin;  // Power pin
const int8_t ZTData            = 7;               // The SDI-12 data pin

// Create a Zebra Tech DOpto dissolved oxygen sensor object
ZebraTechDOpto dopto(*DOptoSDI12address, ZTPower, ZTData);

// Create dissolved oxygen percent, dissolved oxygen concentration, and
// temperature variable pointers for the Zebra Tech
Variable* dOptoDOpct =
    new ZebraTechDOpto_DOpct(&dopto, "12345678-abcd-1234-ef00-1234567890ab");
Variable* dOptoDOmgL =
    new ZebraTechDOpto_DOmgL(&dopto, "12345678-abcd-1234-ef00-1234567890ab");
Variable* dOptoTemp =
    new ZebraTechDOpto_Temp(&dopto, "12345678-abcd-1234-ef00-1234567890ab");

Classes

class ZebraTechDOpto

The Sensor sub-class for the Zebra-Tech D-Opto dissolved oxygen sensor.

class ZebraTechDOpto_Temp

The Variable sub-class used for the temperature output from a Zebra-Tech D-Opto dissolved oxygen sensor.

class ZebraTechDOpto_DOpct

The Variable sub-class used for the dissolved oxygen percent saturation output from a Zebra-Tech D-Opto dissolved oxygen sensor.

class ZebraTechDOpto_DOmgL

The Variable sub-class used for the dissolved oxygen concentration output from a Zebra-Tech D-Opto dissolved oxygen sensor.

Defines

#define DOPTO_NUM_VARIABLES = 3

Sensor::_numReturnedValues; the D-Opto can report 3 values.

#define DOPTO_INC_CALC_VARIABLES = 0

Sensor::_incCalcValues; we don't calculate any additional values.

Sensor Timing

The sensor timing for an ZebraTech D-Opto

#define DOPTO_WARM_UP_TIME_MS = 275

Sensor::_warmUpTime_ms; the D-Opto warms up in 275ms. Maximum warm-up time in SDI-12 mode: ~250ms, give a bit of extra for safety.

#define DOPTO_STABILIZATION_TIME_MS = 0

Sensor::_stabilizationTime_ms; the D-Opto is stable as soon as it warms up (0ms stabilization).

#define DOPTO_MEASUREMENT_TIME_MS = 5335

Sensor::_measurementTime_ms; the D-Opto takes 5335ms to complete a measurement.

• Excitiation time before measurement: ~5225ms
• Maximum measurement duration: ~110ms

Obnoxiously, the sensor will not take a "concurrent" measurement and leave the sensor powered on, so we must wait entire ~5200ms exitation time and the 110ms measurement time each time. There is the ability to do a non-concurrent measurement and leave the sensor powered on, in which case the re-measurement takes ~110ms, but doing it that way the sensor would send an interruption when it was finished, possibly colliding with and confusing other sensor results.

#define DOPTO_EXTRA_WAKE_TIME_MS = 0

Extra wake time required for an SDI-12 sensor between the "break" and the time the command is sent. The D-Opto requires no extra time.

Temperature

The temperature variable from an ZebraTech D-Opto

• Range is not specified in sensor datasheet
• Accuracy is ± 0.1°C

#define DOPTO_TEMP_RESOLUTION = 2

Decimals places in string representation; temperature should have 2 - resolution is 0.01°C.

#define DOPTO_TEMP_VAR_NUM = 0

Sensor variable number; temperature is stored in sensorValues[0].

#define DOPTO_TEMP_VAR_NAME = "temperature"

Variable name in ODM2 controlled vocabulary; "temperature".

#define DOPTO_TEMP_UNIT_NAME = "degreeCelsius"

Variable unit name in ODM2 controlled vocabulary; "degreeCelsius" (°C)

#define DOPTO_TEMP_DEFAULT_CODE = "DOtempC"

Default variable short code; "DOtempC".

Dissolved Oxygen Percent Saturation

The percent saturation variable from an ZebraTech D-Opto

• Range is not specified in sensor datasheet
• Accuracy is 1 % of reading or 0.02PPM, whichever is greater

#define DOPTO_DOPCT_RESOLUTION = 2

Decimals places in string representation; dissolved oxygen percent should have 2.

#define DOPTO_DOPCT_VAR_NUM = 1

Sensor variable number; dissolved oxygen percent is stored in sensorValues[1].

#define DOPTO_DOPCT_VAR_NAME = "oxygenDissolvedPercentOfSaturation"

Variable name in ODM2 controlled vocabulary; "oxygenDissolvedPercentOfSaturation".

#define DOPTO_DOPCT_UNIT_NAME = "percent"

Variable unit name in ODM2 controlled vocabulary; "percent" (% saturation)

#define DOPTO_DOPCT_DEFAULT_CODE = "DOpercent"

Default variable short code; "DOpercent".

Dissolved Oxygen Concentration

The DO concentration variable from an ZebraTech D-Opto

• Range is not specified in sensor datasheet
• Accuracy is 1 % of reading or 0.02PPM, whichever is greater

#define DOPTO_DOMGL_RESOLUTION = 3

Decimals places in string representation; dissolved oxygen concentration should have 3 - resolution is 0.01 % / 0.001 PPM.

#define DOPTO_DOMGL_VAR_NUM = 2

Sensor variable number; dissolved oxygen concentration is stored in sensorValues[2].

#define DOPTO_DOMGL_VAR_NAME = "oxygenDissolved"

Variable name in ODM2 controlled vocabulary; "oxygenDissolved".

#define DOPTO_DOMGL_UNIT_NAME = "milligramPerLiter"

Variable unit name in ODM2 controlled vocabulary; "milligramPerLiter" (mg/L)

#define DOPTO_DOMGL_DEFAULT_CODE = "DOppm"

Default variable short code; "DOppm".