MH-Z19-like NDIR CO2 Sensor HC8 Found And Explored [Hackaday]
![](https://i0.wp.com/hackaday.com/wp-content/uploads/2022/08/co2sensor-dis-3-6LpSc-Y7Gt-orig.jpeg?resize=800%2C600&ssl=1)
While on the search for an alternative to directly buying the fairly expensive MH-Z19 CO2 sensor, [spezifisch] came across a ‘BreeRainz’ branded gadget (also found under other brands) that claimed to use an NDIR (Non-Dispersive Infrared) sensor for measuring CO2 levels, while costing only €25. This type of sensor allows for CO2 levels to be measured directly, rather than inferred, making them significantly more precise.
![The BreeRainz DM1308A device cracked open.](https://i0.wp.com/hackaday.com/wp-content/uploads/2022/08/co2sensor-dis-1-0Y4IeYsmKL-orig.jpeg?resize=400%2C300&ssl=1)
After cracking the gadget open (literally, due to the hidden screws), the CO2 sensor is clearly visible. While superficially identical to an MH-Z19, the NDIR sensor is actually called ‘HC8’, is produced by 广州海谷电子科技有限公司 (Guangzhou Haigu Electronic Technology Co., Ltd.). While being pin-compatible with the MH-Z19, its UART protocol is not the same. Fortunately there is a datasheet to help with implementing it, which is what [spezifisch] did.
This raises the question of whether harvesting NDIR CO2 sensors like this is worth it to save a few Euros. A quick look on German Amazon shows that the device in question currently costs €35, while a genuine MH-Z19 can be bought for €25 or less. There are also many MH-Z19 models (B, C and D), which cover an even wider price range. All of which points to finding an NDIR sensor-containing device can be interesting when it’s on sale, but if all you care about is the sensor itself, it’s probably best to just buy them directly.