Adapter for gang-flashing CB2S modules

A few weeks ago I needed to stock on smart power outlets for my lab. I ordered known WiFi-controlled outlets that have been known by me to contain esp8266, so that I could flash them with esphome. To my surprise, instead of a very well-known esp8266 module. They had some weird CB2S module from Tuya.

Well, shit happens. Seems that I’ve missed yet another round of cheap IoT modules. These have Beken BK7231N modules inside. And are somewhat supported by OpenSource software stack. So our options are: replace the module with an esp8266 one, like what this guy did or deal with it.


I won’t do a full writeup of hacking the firmware. Seems there are a lot of people that have invested a lot of time to make those working. The only relevant details here are: They are also flashed via serial port, much like the ESP8266, they have OpenBeken firmware, that looks much like tasmota and esphome fork that should be merged pretty soon to esphome master.

Flashing in bulk

The problem flashing these modules on bulk is – you have to disassemble and solder the leads to the edge connector. It’s okay for a one-time solder job, but is a totally no-go when you have to do it in bulk. So, I scratched my head, fired up SolveSpace and after some trial and error made this weird-looking device.

The idea behind it is pretty simple. Just a bunch of spring-loaded pogo pins and a piece of plastic to hold things in place. No soldering, just attach it and remove once you are done.

Where to get one?

As usual, you can grab the design files on my thingiverse:

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