Sonoff B1 bulb

[trumee]

Has anybody tried flashing Sonoff B1 bulbs? There dont seem to be any holes for a header on the PCB.

[Justblair]

You have a photo?

Oh scrap that, i found one... Does not look hard to solder to,

Had a brief glance through the tasmota code, looks like the protocol for the 9231 is very similar to the 9291. The 9231 only requires 48bits of data (16bit x 3 channels) compared to 64bits (16bit x 4 channels) of the 9291.

The white leds seem to be controlled from a second 9231. I cant see on the schematic what pins this connected to. The Tasmota code will contain this information somewhere.

[trumee]

I was able to solder on the 3 pads. But my stranded wire doesnt stick to the GND pad. How do i put this into flash mode? There is a GPIO pad, do i need to do something with it?

[Justblair]

Your gnd is probably a little harder as it is attached to a ground plane (heat wicking) Try cleaning the pad first with a fibreglass brush or something a little abrasive (tiny bit if sandpaper?)

There is a pin marked gpio0 on the B1 (well at least in the picture I can find), connect this to gnd. On the next startup you should be in boot mode