Module/LM75
Overview
The National LM75 (now Texas Instruments LM75A) is an affordable temperature sensor that could be used e.g. to measure battery temperature.
| Module name | meteo/temp_lm75 |
| Sensor type | temperature |
| Range | -55°C .. +125°C |
| Resolution | 0.5°C |
| Refresh rate | 3Hz |
| I2C address | 0x90 |
Hardware
The LM75 can be directly interfaced to the Paparazzi autpilot 3.3V I2C interfaces.
Wiring
| Autopilot I2C pin | Autopilot I2C | LM75 |
| 1 | GND | GND |
| 2 | ||
| 3 | +3.3V | +Vs |
| 4 | SDA | SDA |
| 5 | SCL | SCL |
Usage
To use the temperature sensor add the module to your airframe file.
| File: conf/airframes/myplane.xml |
<modules>
<load name="temp_lm75.xml"/>
</modules>
|
Result message
The raw data (itemp) and the converted result (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="TMP_STATUS" id="86">
<field name="itemp" type="uint16"/>
<field name="temp" type="float" unit="deg_celsius" format="%.2f"/>
</message>
|
Sample log file lines
2.663 TMP_STATUS 123 45 22.5 2.908 TMP_STATUS 123 46 23. 3.333 TMP_STATUS 123 47 23.5 3.665 TMP_STATUS 123 47 23.5