Take a look at the picture at the bottom of the github readme.
Here is how I did it (can’t promise I didn’t make a mistake though, real or written):
Connect to GND:
GND on serial adapter
grab all below dupont jumpers with alligator clips
pin with GPIO0 arrow, marked 1 on board
dupont jumper M/M
pin next to GPIO0 arrow, marked 2 on board
dupont jumper M/M
pin with GPIO2 arrow
press a dupont jumper M/M on top of the pin and use an alligator clip (preferably with a sleeve, since this is for plastics) to hold it in place with the help of the nearby white connector (should be just close enough)
GND on external power supply
Connect 3v3 to external power supply:
dupont jumper to whatever your power supply offers
had to crank to 3.45v -measured- for it to work
Connect RX/TX to your serial adapter
dupont jumpers according to your adapter
I used pin headers (a 4-pin 2.54mm single row -the ones meant to be soldered-) to plug into the 4 pins (3v3/GND/TX/RX) of the board, with the dupont jumpers on it (jumpers alone could easily touch below the board, pin headers remain parallel!). It will skew a little with gravity (jumpers’ weight), which should ensure continuity.
Ignore the yellow and white wires on the github picture.
Make sure everything is properly connected with a quick continuity test.
There sure are better ways to do it, but I did it with what I had on hand; worked for me… I tried without the external power supply at first, but that didn’t work.
It might seem long “in written format”, but it was actually really fast, and didn’t require messing with the board’s soldering.
Sorry I can’t post pictures, the box is all closed up again…
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Alright! Can’t believe it was that simple! I would never have thought that I need to ignore the yellow and white wires on the github picture… That was the only part that was bugging me.
Worked like a charm! Thanks for the help and the clear instructions!
Here’s to never having to open those purifiers again! Cheers!
I reckon I got quite lucky and got mine flashed 1st shot just using the ttl adapter for power. I mostly followed your method. I was connected to my HA server (old laptop).
I thought I’d take some flicks to contribute to making the flashing easier to follow for others.
I managed to flash using only dupont cables and pin headers. No soldering or even clips! I had these but they were no good for gpio2 so I abandoned them.
Fantastic, the only thing I missed when I posted… unfortunately mine was already flashed and repacked by then. Thanks.
As I mentioned before, using a power supply, it wouldn’t cooperate until I let the decimal point go up a bit (3.45V), so maybe a USB adapter a bit more lax on the power it lets flowing through works just fine here, without external power. I just tested mine, it outputs near exact, 3.305V.
I measured ~3.3V on mine. Could also possibly depend on how good your connections are and length of wires? Could be some extra resistance/voltage drop if your connections aren’t great etc? I was thinking about this power issue as I went and used as short wires as possible etc. Possibly also an area that might benefit from a soldered approach. Especially if you don’t have a variable power supply (I don’t).
Esp32 can be picky regarding power supply - it must be powerfull enough, since current spikes can be well over 1A. So, if you have some small (or cheap) PSU this could be the problem. If i program my esp32 it won’t program when powered via (low power) usb port… it must be USB3.0 .
I used USB-C (newer adapter), yet no joy… So I think the source of the issue is weirder than that.
But then again, between the computer, drivers, power saving features, the quality of the adapter, connections, and everything else on the board’s side… so many things involved
They also mention a double-beep in the README, when the board powers up; even though I flashed it successfully, I never heard those… In case anyone is waiting for them, don’t, it just might be working already (try to flash and see if the serial port opens). Guessing there could be slight differences between versions/locations…
I just remembered: a while ago i decided to play with newly arrived wemos d1. I coudln’t get it to flash - it didn’t even start to flash. After a while i managed to solve it by (re)installing original wemos drivers on my windows 11, although drivers were installed, i flashed naords with same uart chio before… perhaps fake chinese uart chip…?
Good point. I can’t remember what state it was before I flashed it (had done a bunch of resets & reconfigs…). I updated the original post to mention this. Thanks.
Does anyone have any tips on how to get the covers off? I can get the side pannels all the way down to the top, but those last tabs seem darn near impossible for me to get. I’ve watched several videos and still can’t seem to get it.
