Hit enter after type your search item
Home / Products / USB Relays / TSTR04 – 4 Channel Outputs 4 Temperature Sensors USB Relay (Thermostats)

TSTR04 – 4 Channel Outputs 4 Temperature Sensors USB Relay (Thermostats)


This is a TSTR04 USB relay board which has an OLED display and 4 temperature sensor ports.

In “Normal” mode, you can easily control this relay board by your computer or smartphone via Bluetooth. In “Auto” mode, you can set a threshold value, to let the relay turn ON/OFF based on the temperature. So, you can use it as a thermostat.

The communication method also can be changed easily. Remove the Bluetooth Bee module, it becomes a USB relay. Plug a WiFiBee on it, it becomes a Wi-Fi relay.

The TSTR04 provides four volt free contact relay outputs with a current rating of up to 10Amp each. The TSTR04 module can be powered by USB bus or from a 5V DC power supply. The DC input jack is 2.1mm with positive core polarity, the relays are SPDT types. If you want to power it with DC 12V or 24V, you just need a 12V/24V-5V DC converter.

Note: DS18B20 sensor is not included. You need to buy it separately.

Note: You must need an overheat protection device to avoid the risk of fire if you use it in any heating system.


Relay power rating
If the relay is used at a voltage or current exceeding this specification, the life of the contacts may be significantly shortened.

A full datasheet for the relays used on the TSTR04 is here: G5LA datasheet

If you use DC power, the Input voltage should be DC 5V.

First Step – Install the Driver
The TSTR04 module uses FT232RL USB to UART chip. Before using the TSTR04 you will need to download the FT232RL Driver.

Connect the TSTR04 and windows will detect it and ask for the drivers. Point windows to the inf folder and it will install the driver.

The TSTR04 will now appear as a com port.

The TSTR04 operates with an easy to use command set as described in the table below.

TOSR04-T Baud rate: 9600

Test program
To get the TSTR04 up and running in the minimum amount of time we have put together an example program to demonstrate the functionality of the module.


  • Facebook
  • Twitter
  • Linkedin
  • Pinterest

Leave a Comment

Your email address will not be published. Required fields are marked *

seventy eight − = 73

This site uses Akismet to reduce spam. Learn how your comment data is processed.

This div height required for enabling the sticky sidebar
Ad Clicks : Ad Views : Ad Clicks : Ad Views : Ad Clicks : Ad Views :