Downgrading BC127 firmware?

We have a product shipping with 6.0.35. About the time we finished our final tests and got ready to stuff product in boxes, 6.0.39 came out and the TWS modes didn’t work properly. So we bailed on that and have shipped quite a bit of product using 6.0.35.

We have new things coming out and I hate to stick with something that old since so many bugs have been fixed. Unfortunately the DFU utility doesn’t seem to want to downgrade so it’s hard to run experiments on compatibility - I need for our new product to coexist in the universe with our old one. I’m worried that if I take a working product (speaker) with 6.0.35 and upgrade it to 6.1.whatever, it will get stuck that way and I will have ruined a useful board.

Does anyone have any specific knowledge of whether I could take a 6.0.35 board, load in something new and then put 6.0.35 back again?



Pretty sure you can do this as long as you don’t go jumping between 4.x, 5.x and 6.x. The boot loader is the only thing to really worry about here

If you have access to the SPI interface then you can buy the SPI to USB conversion chip from digikey and move around whatever firmware versions you want.