LMT01 temperature sensor~
This feature is included only in
When compiling your build add the following to
#ifndef USE_LMT01 #define USE_LMT01 // Add support for TI LMT01 temperature sensor, count pulses on single GPIO (+0k5 code) #endif
The Texas Instruments LMT01 is 2-pin digital output temperature sensor that converts temperature directly to a sequence of digital pulses, reading a range from -50°C to +150°C with up to 0.5°C accuracy. It is available in a DIY-friendly small TO-92 package.
Connection is by a single GPIO to count the pulses, which needs a driver transistor to convert the small current changes into logic level voltage swings.
- LMT01 data sheet
- LMT01 product page with links to evaluation board and training video and sample code.
Limitations of current implementation:
- Only the simple linear conversion is used. The datasheet suggests the use of a look-up table to improve the accuracy at the edges of the range, this is not yet implemented.
- The sensor code only supports one LMT01 instance.
Choose a pin GPIOx. The GPIO can be connected to the LMT01 via a NPN transistor, so current pulses pull the GPIO line low: see Figure 32 in the LMT01 datasheet.
In the Configuration -> Configure Module page assign:
- GPIOx to
After a reboot the sensor will be detected and displayed. If the connection is not working, the pulse counting will timeout and you will see
null displayed for the temperature.