Module/TronSens HTM B71
Overview
The TronSens HTM B71 (now sold as IST HYT-271?) is a relative humidity and digital temperature sensor. Early versions seemed to have issues with other devices on the same I2C bus.
| Module name | meteo/humid_htm_b71 |
| Sensor type | humidity, temperature |
| Range (humidity) | 0 .. 100 %RH |
| Range (temperature) | -40°C .. +125°C |
| Resolution (humidity) | ? %RH |
| Resolution (temperature) | 0.01°C |
| Refresh rate | 4Hz |
| I2C address | 0x28 |
Hardware
The sensor board can be directly interfaced to the autopilots I2C 3.3V interface
Wiring
| Autopilot I2C pin | Autopilot I2C | HTM B71 | HTM B71 pin |
| 1 | GND | GND | 2 |
| 2 | |||
| 3 | +3.3V | Vdd | 3 |
| 4 | SDA | SDA | 1 |
| 5 | SCL | SCL | 4 |
Usage
To use the humidity sensor add:
| File: conf/airframes/myplane.xml |
<modules>
<load name="humid_htm_b71.xml"/>
</modules>
|
Result message
The raw data (ihumid/itemp) and the converted result (humid/temp) is written to the log file. The message is automatically sent when new data is received, it does not have to be added to the telemetry file.
| File: conf/messages.xml |
<message name="HTM_STATUS" id="115">
<field name="ihumid" type="uint16"/>
<field name="itemp" type="uint16"/>
<field name="humid" type="float" unit="rel_hum" format="%.2f"/>
<field name="temp" type="float" unit="deg_celsius" format="%.2f"/>
</message>
|
Sample log file lines
15.891 123 HTM_STATUS 4807 5920 29.35 19.2 16.143 123 HTM_STATUS 4807 5917 29.34 19.17 16.391 123 HTM_STATUS 4807 5917 29.34 19.17 15.643 123 HTM_STATUS 4809 5917 29.35 19.2