10 LM75AD

Michael Ingraham edited this page 2019-11-19 10:42:38 -05:00

Table of Contents

• Configuration
• Wiring
• Tasmota
• Commands
• Breakout Boards

The LM75AD is an I²C temperature sensor that converts temperature directly to digital signals from -55°C to +125°C and achieves an accuracy of 0.125°C

Some features of the LM75A chip not implemented in this driver:

• Programmable temperature threshold and hysteresis set points
• Stand-alone operation as thermostat at power-up

LM75A Datasheet

Configuration

Wiring

LM75AD	ESP8266
VCC	3.3V
GND	GND
SDA	GPIOx
SCL	GPIOy
OS	not used

The driver currently only allows the use of a single LM75AD sensor on any of the addresses configurable through pins A0, A1 and A2. These are conveniently broken out on the breakout board either as pins or as solderable joints as can be seen on the example breakout board.

These pins need to be tied down to either GND or VCC (3.3V) and the resulting I²C address will be set during power-up according to the table:

Tasmota

In the Configuration -> Configure Module page assign:

1. GPIOx to I2C SDA (6)
2. GPIOy to I2C SCL (5)

After a reboot the driver will detect LM75AD automatically and display Temperature.

Commands

TempOffset can be used for calibrating the measured temperature. This setting affects all temperature sensors on the device.

Breakout Boards

Can also be used standalone if soldered to a board given the diagram is used

R1 and R2 are pull-up resistors which are required by the I²C bus to operate properly. If you have other I²C sensors with pull-up resistors connected to the same I²C bus it's probably not necessary to have them.

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