Teyleten Robot SCD41 Gas Sensor Module CO2 Carbon Dioxide Temperature and Humidity Gas Sensor Module I2C

This is a good sensor at half the price of the identical unit from other sources. Be careful when establishing the ground. In my test set up I used a separate power source from the Arduino and failed to use a common ground. This cost me two days of debugging until I figured out my mistake. Keep in mind that this Is a precision product. Grounding and shielding will be important if used in a field environment.

This sensor worked well with esphome and reported very plausible values out of the box even with self-calibration disabled. I believe it's a knock-off of the original sensor, but it seems to work well enough. If you have issues with noise, note that these sensors are sensitive to airflow and sound due to how they measure CO2. The sensor should be exposed to open air, but not directly forced airflow.

I'm running Tasmota on an ESP32 with a 4000mAh battery and OLED display. Totally easy to use, just plug it in. Uses I2C, Tasmota sees it without any configuring.

This SCD41 sensor performs well for DIY projects once you understand how to program and communicate with it. Readings for CO₂, temperature, and humidity are accurate, and integration with microcontrollers like ESP32 is straightforward after setup. There’s a small learning curve, but once configured properly it works reliably.

I tried with the Sensirion_I2C_SCD4x and SparkFun_SCD4x_Arduino_Library on an Arduino Nano. Plus Sensirion raspberry-pi-i2c-scd4x on a raspberry pi. In all cases , it can return the serial number but never returns any information requesting measurement or other settings commands. Just hangs. My guess this is bad manufacturing run that might have some good ones that are being unloaded. I expect that on Aliexpress not on Amazon. Expense way for Beta testing.

Other sensors with this chip (SCD41) cost almost twice what this one cost. It seems to work just fine.

I don't know how to rate this one. It is a sensor that is finicky for the solution I'm attempting to use. I paired it with an ESP32 and another sensor (PMS5003 Air Quality Sensor) which is working fine. The SCD41 didn't want to work and gave me several unknown errors. Searching online and Google and AI tells me that the power seems to be the issue so I've currently got a capacitor on order to see if I can rectify the power issues and get this sensor working but seemingly it is much more finicky that the other temp/humidity sensors I've used previously. I will also say, I'm a tinkerer so this could all be my fault so I will take some accountability and warn that this could be a me problem. Device was packaged well and was delivered on time, and was priced right for the product so take it with a grain of salt.

I used it with ESPHome and an ESP32 dev kit. It needs a stable 3.3V power supply otherwise the sensor disconnects sometimes. Make sure to turn off auto calibration. It usually takes couple minutes after startup to stabilize temperature and humidity.