| We used a few thousand of the D1 mini (ESP8266) for our air quality monitor kits and had a couple of issues. On some of them the WiFi would not work at all. Kind of like the onboard antenna was not properly connected. Other died after a few months without any special reason that we were aware of. Another problem with these boards is that you do not know exactly the specs of the other components. For example we got different rated voltage regulators (5v to 3.3) that caused some issues because sensors we put on the 3.3v did have higher requirements. Interestingly we had more issues with the "original" ones than the clones. I actually wrote a small blog post about it [1]. Another issue is that it is difficult to get proper ROHS and REACH certifications for these modules. This makes it difficult if you want to use them in a finished and certified product. All of these issues added up and we made the switch away from the module and now put the ESP32-C3-MINI directly onto the PCBs of our indoor and outdoor air quality monitors. Together with an external hardware watchdog, this seems to pretty much eliminate all issues we had. If you are interested in the shematics, its all open source [2]. [1] https://www.airgradient.com/blog/d1-mimi/ [2] https://www.airgradient.com/open-airgradient/instructions/ov... |