Don't pull down the pull up....
Have you ever fucked up, tried to fix it, it didn't work and you got more and more frustrated? Yeah, me to. Today this happened, and i was trying to fix it, didn't understand why it didn't work and became super frustrated.
My issue was that I could not upload code to an ESP that we had soldered sensors and output devices to, but it worked fine before we soldered it... So our natural response to the problem was to desolder everything and solder it to another ESP.... it didn't work there either...
back to the drawing table... after inspecting all the solder points several times, disconnecting the LED rings (that could be drawing a lot of power), and pulling out several patches of hair, I decided that enough was enough. I cut off the IR sensor, with some pliers, planing to throw it away in frustration. But lo and behold, the fucking shit booted, connected to WiFI and stated that is was ready to send data.
Could it be that my simple IR receiver sensor caused my ESP to stop in it boot sequence.
I connected it again and tried to rebot, no luck, disconnected and it booted.
So what the hell is going on?
Well, it turns out that when the ESP8266 boots (or more specific, when the Wemos D1 R1), it sets, among others, Pin D4 to HIGH. And our sensor then connected this to ground effectively pulling it down. And for some reason I do not know the answer to, the D4 pin must be HIGH for the boot process to complete.
A sane person would then solder the sensor to another pin, but if you saw my lightning talk, you know that I don't operate that way. I wanted to make that sensor and Wemos board my bitch.
So i attached wires with female contacts to the existing wire. Duct taped them together so that their alignment don't changes and connected the sensor in those connectors.
So whenever we want to boot that heart rate node, we must remove the sensor, wait until the heart lights up, and then reconnect the sensor. Fuck you Wemos and your boot sequence.....
We apply for the badge "I fixed it"