I was writing a post to ask for help (I’ll leave that query at the bottom) and whilst trying things everything went wrong. I plugged, what I’m 95% sure, was a comms wire back into the module that I was testing (already connected to a cell) and puff the Wemos chip let out the magic smoke, never to be put back in again. Damn, nevermind I have another fresh one. Got that sorted and programmed and then plugged it back into the other modules, but now I’m not seeing any comms at all between module and controller.
OK, I’m going to write as I test, as this has got even worse.
So I sorted the issue above, by trying different jumpers. I gradually added in modules. As I added the third module in, this time 100% checked the correct cables are used, it just fried the second wemos. More smoke, game over.
How is one of my modules passing voltage into the comms lines? There’s no obvious issue with that module, it still is giving me a blue double blink.
I’ve just checked with my DMM and the RX1 port is showing full cell voltage of 3.43V!
So that’s what destroyed my 2 Wemos boards. I didn’t even build these modules, I got them from the OEMon store.
So first thing I need to do is condemn this dangerous module. Is there any testing I can do that may help track a potential fault issue with other’s boards? I’d be willing to post it to @stuart if it would be useful to look at.
The second thing I need to do is order some more Wemos D1 Pros.
Thankfully I ordered another set of modules from JLC PCB as I’m thinking of adding more cells to the battery I haven’t built yet (don’t ask!).
So here is the original issue I was trying to solve before all of the magic smoke started to fly:
I’ve got four modules (erm, not any more!) and one controller (now missing the Wemos d1 pro). I have had all modules running fine before today (how ironic).
I’m still in my testing phase. So I’ve just got 4 18650 cells in a holder that I’m using to power a router. Each cell has a lead with a JST for a BMS module.
One of the cell modules has stopped working (not the one that just fried the Wemos boards). It immediately goes into Bypass when I plug it in and there is no communication beyond the module. And all other comms fail. I have tried plugging it in to the controller on it’s own, but no change.
I tried plugging it into my laptop, but as soon as I connect it to my USBASP I get a warning message from windows saying USB Device Not Recognised. When I try and program through Platform IO it fails because it can’t find the board. When I unplug the board from my USBAPS the programmer reappears in the device manager.
What am I doing wrong? Just how many things can I bugger up in one day. Any help, whiskey or condolences gratefully received!