SM-039 BL602 module


I have a Sonoff/Ewelink BL602 device with module SM-039. This is not a Trolink module, as I first thought. Does anyone know who manufactures this module and where I can get a datasheet please?


It’s a Bouffalolab BL602/BL604.

1 Like

Yes, but who makes the module?

Doesn’t matter. Programming/coding is the same. This one is probably generic - no name module.

I know how to program it but cannot trace some of the pins on the module. I wanted a datasheet of the module to confirm GPIOs

There are 6 pins and 6 points on the module. Measure it and you’ll know.

I just doubt my ability. Obviously the 6 labelled pads are what they are, but the 11 others…

2 are clearly 3V3 and GND.

I have this so far

Just solder wires directly to the points marked on the board.

thanks but I’m not sure how soldering wires to the pads with labels helps me identify the GPIOs of the contacts unmarked along the bottom

What is the reason of the need to identify the pins?


If that’s intended for commercial projects, please contact or

I am just a curious enthusiast and would like to learn more from official datasheet

This may be the valid reason :slight_smile:
Do you want to flash it or connect it to something?

indeed I do!

opensource BL602 projects and stuff

I understand. Since you want to flash and can’t recognise the pins, soldering the wires on the board will solve the issue, won’t it? You have the leads, including RX and TX.
See this thread in the Elektroda forum.

yes. I can flash something to then try an LED on each on the module connector pads I guess. By process of elimination I could determine the GPIOs of each.

See this thread in the Elektroda forum.

yes. that’s from me :wink:

Well, you have to keep trying or change the object of interest. There are so many WiFi modules around. I’m sure you’ll find something sexy and with documentation.

lol. sexy modules. yes, I have many others, but this one has my interest for the moment. I will work it out :smiley: