Sensors

Tip: Quickly find and jump to sensors from the Supported Devices page.

ISensor Interface

All sensors use the ISensor interface. This requires some functionality common to all sensors.

Here are the methods provided:

• bool Test()
  • Checks if the sensor is working correctly. The implementation depends on the specific sensor. If there is no way to test the sensor accurately, or it is not implemented, this must return true. This method should never throw an exception.
• void UpdateState()
  • Updates the sensor. Specific actions depend on the sensor, but getting readings is very common. Make sure to call this every time you want to get a new reading from your sensor.
• DataUnit GetData()
  • Gets sensor information in a DataLog-compatible format.
• string System (Property)
  • This is to be used by the user to associate a task to a sensor, to make it easier to tell multiple sensors apart. For example, "Ground Temperature", or "Front-Right Wheel".
• bool TraceLogging (Property)
  • See Trace Logging.

BME280

Implementation | Datasheet | Adafruit Breakout

The BME280 is a high-accuracy air temperature, humidity, and pressure sensor. It uses the I2C or SPI protocols, and is fully supported in Scarlet.

Create an instance using either of the two constructors:

new BME280(II2CBus I2CBus, byte DeviceAddress)
new BME280(ISPIBus SPIBus, IDigitalOut ChipSelect)

Now, you'll need to apply a configuration:

MyBME.Configure();

You can also create a custom configuration, and apply that instead:

BME280.Config MyConfig = BME280.DefaultConfig;
MyConfig.MeasureHumidity = false;
MyBME.Configure(MyConfig);

Then, as with any other sensor, call UpdateState(), and then get the readings from the Temperature, Humidity, and Pressure properties as needed.

Here are the options that you can configure:

Option	Default	Values	Description
HumidityOversampling	OS_1x	BME280.Oversampling enum values	Sets oversampling on temperature measurements, determining capture time. This is used to reduce noise.
MeasureHumidity	true	true/false	Determines whether humidity measurements are carried out. Turning off unwanted measurements reduces power usage and increases measurement speed.
PressureOversampling	OS_1x	BME280.Oversampling enum values	Sets oversampling on temperature measurements, determining capture time. This is used to reduce noise.
MeasurePressure	true	true/false	Determines whether pressure measurements are carried out. Turning off unwanted measurements reduces power usage and increases measurement speed.
TemperatureOversampling	OS_1x	BME280.Oversampling enum values	Sets oversampling on temperature measurements, determining capture time. This is used to reduce noise.
Mode	NORMAL	BME280.Mode enum values	Chooses if the device takes measurements, and in what manner.
StandbyTime	TIME_500us	BME280.Oversampling enum values	The amount of time to wait between measurements in NORMAL mode.
IIRFilterTimeConstant	FILTER_OFF	BME280.Oversampling enum values	How many samples should be averaged for temperature and pressure readings. Used to smooth readings.
Use3WireSPI	false	true/false	Whether to use 3-wire SPI mode (usually false).

Note that temperature measurement cannot be disabled, as it is required for the other two measurements to work.

DataUnit

Like any sensor, the BME280 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"Temperature"	double	The air temperature, in 0.01 °C increments.
"Pressure"	double	The air pressure, in 1/256 Pa increments. double.NaN if pressure measurements are not taken.
"Humidity"	double	The air humidity, in 1/1024 %RH increments, from 0.0 to 100.0. double.NaN if humidity measurements are not taken.

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BNO055

Implementation | Datasheet | Adafruit Breakout

Documentation to be added.

DataUnit

Like any sensor, the BNO055 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"X"	float	Depends on vector mode
"Y"	float	Depends on vector mode
"Z"	float	Depends on vector mode

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INA226

Implementation | Datasheet

The INA226 is a high- or low-side current shunt monitor. It uses the I2C protocol, and is fully supported in Scarlet.

Usage is very easy, start by constructing an instance:

new INA226(II2CBus Bus, byte DeviceAddress, float MaxCurrent, double Resistor, INA226.AveragingMode Avg = AveragingMode.Last1, INA226.ConversionTime VBusTime = ConversionTime.Time1100us, INA226.ConversionTime VShuntTime = ConversionTime.Time1100us)

The advanced parameters all have default values that are reasonable. If you have specific requirements, you can tweak them.

Once you have your instance, you're ready to go. Simply call UpdateState() to get new readings from the device, then use the GetBusVoltage(), GetShuntVoltage(), GetCurrent(), or GetPower() methods to get the data you need.

DataUnit

Like any sensor, the INA226 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"BusVoltage"	double	The voltage at the bus line (the supply voltage for high-side sensing)
"ShuntVoltage"	double	The voltage across the shunt resistor
"Current"	double	The calculated current going through the shunt resistor
"Power"	double	The calculated power being drawn by the load

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LS7366R

Implementation | Datasheet

The LS7366R is a high-speed dedicated encoder counter. It uses the SPI protocol, and is fully supported in Scarlet.

To start using it, construct an instance:

new LS7366R(ISPIBus SPIBus, IDigitalOut SPI_CS)

Then, create and apply a configuration:

LS7366R.Configuration Config = LS7366R.DefaultConfig;
Config.QuadMode = LS7366R.QuadMode.X1_QUAD;
MyEncoder.Configure(Config);

You are now ready to get data. Simply call UpdateState() to get the newest data from the device, then access the count by getting the Count property.

Optionally, you can register for Overflow/Underflow events. To do this, implement a method with the required signature, or expand an existing event handler, then register it:

public void EncoderOverflowTriggered(object sender, LS7366R.OverflowEvent eventData)
{
    bool WasOver = eventData.Overflow;
    bool WasUnder = eventData.Underflow;
    ...
}

MyEncoder.OverflowOccured += this.EncoderOverflowTriggered;

If you want to enable/disable counting without re-sending the entire configuration, you can do so by using EnableCount(bool Enable).

Here are the configuration options:

Option	Default	Values	Description
QuadMode	NON_QUAD	LS7366R.QuadMode enum values	Determines the type of encoder that the device is expecting. If this is not set correctly, you will get no or incorrect readings. Check the specifications of the connected encoder for this information. If you are not sure, X1_QUAD is a good guess.
CountMode	FREE_RUNNING	LS7366R.CountMode enum values	This is a bit complex, so you'll want to look in the LS7366R datasheet (page 4, MDR0 section) to understand the modes.
IndexConfig	DISABLE	LS7366R.IndexConfig enum values	This is a bit complex, so you'll want to look in the LS7366R datasheet (page 4, MDR0 section) to understand the modes.
CounterMode	BYTE_4	LS7366R.CounterMode enum values	The number of bytes to use for the counter data
CountEnable	true	true/false	Whether to count incoming encoder pulses. If false, Count will not change.
DivideClkBy2	false	true/false	?
SynchronousIndex	false	true/false	?
FlagOnIDX	false	true/false	Whether to put Index state into STR register
FlagOnCMP	false	true/false	Whether to put Compare (Counter = DTR) state into STR register
FlagOnBW	false	true/false	Whether to put Borrow (Counter underflow) state into STR register
FlagOnCY	false	true/false	Whether to put Carry (Counter overflow) state into STR register

DataUnit

Like any sensor, the LS7366R outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"Count"	int	The current differential encoder step count since the sensor began reading

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MAX31855

Implementation | Datasheet | Adafruit Breakout
Documentation to be added.

DataUnit

Like any sensor, the MAX31855 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"IntTemp"	float	The internal temperature of the sensor itself
"ExtTemp"	float	The thermocouple's temperature
"Fault"	string	Any faults that are detected

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MPU6050

Implementation | Datasheet | Sparkfun Breakout
Documentation to be added.

DataUnit

Like any sensor, the MPU6050 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"AccelX"	double	X-direction accelerometer reading
"AccelY"	double	Y-direction accelerometer reading
"AccelZ"	double	Z-direction accelerometer reading
"GyroX"	double	X-direction gyroscope reading
"GyroY"	double	Y-direction gyroscope reading
"GyroZ"	double	Z-direction gyroscope reading

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MQ135

Implementation | Datasheet
Documentation to be added.

DataUnit

Like any sensor, the MQ135 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"PPMReadingCal"	float	The air pollutant PPM, using the given calibration parameters

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MTK3339

Implementation | Datasheet
Documentation to be added.

DataUnit

Like any sensor, the MTK3339 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"HasFix"	bool	Currently always true
"Lat"	float	Latitude
"Lon"	float	Longitude

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VEML6070

Implementation | Datasheet | Adafruit Breakout
Documentation to be added.

DataUnit

Like any sensor, the VEML6070 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"UV"	int	UV light reading in μW/cm^2

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VH400

Implementation | Info Page
Documentation to be added.

DataUnit

Like any sensor, the VH400 outputs DataUnit objects using GetData(). Here is the format:

Name	Type	Meaning
"RawReading"	double	The voltage that the sensor is outputting
"Multiplier"	double	The currently set voltage multiplier
"VWC%"	float	The soil moisture, in %VWC from 0.0-1.0, or -1 if the input is not valid

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