Clone Wemos D1 mini boards intermittent reset and boot problems. Inadequate voltage regulators!

I've recently been experimenting with the ESP8266 modules and made a YouTube statistics counter as the first and experimental project. I used a NodeMCU for that which gave me no problems at all. However there is a smaller board, the Wemos D1 mini which on first impressions looks like a more ideal board for final projects and can easily be soldered to veroboard and prototyping boards.

The problem I had was my boards were clones as the originals no longer seem to be made and sellers advertising genuine boards (even showing a photo of the genuine board) are sending clone boards instead. Now that may not seem like a bad thing but I had constant intermittent reboot problems and the board would stick on the bootloader in flash mode if the 5V supply rail was ever so slightly above 5V. That meant it would boot connected to some devices that provide USB power and not boot on others.

This was driving me nuts and I wasted a lot of time trying to find the problem thinking my code was at fault believing the intermittent reboot was due to a stack overflow. I came across this reddit post   / warning_clone_wemos_d1_minis_with_only_150...   which shows that mostly these clones come with voltage regulators that cannot handle the load the ESP8266 puts on them. Uh oh.

This post is dated 2018 and a quick look at my boards, from different sellers had voltage regulators marked 4A20 which indicates it can supply a maximum current of 150mA. However the ESP8266 draws a peak current of 430mA especially at boot.

So in this video I replace that regulator with a more capable AMS1117-3.3 which fixes that problem. However it didn't fix the won't boot if 5V supply is just over 5V; my PS4 outputs nearly 5.2V. A bit high maybe but within the USB specification of 4.75-5.25V.

Ultimately it resulted in a fail with the end result being stuck with a useless board that could not be used. These boards are still being sold and will not work nor can ever work properly due to inadequate components fitted instead of the components fitted to the original Wemos / Lolin spec.

It makes me wonder why even 2 years later these are still being sold. But with them being so cheap many will never get returned as inexperienced hobbyists may well give up on them believing their code or their circuit is at fault.

In the end my hammer had to come out especially that some of the video didn't get recorded as I hit the pause button in error. I'll add time stamps below if you don't want to watch it all.

2:54 - removing the old regulator & rant over Chinese fakes
5:00 - replacing the regulator
11:10 - testing
12:30 - trying to diagnose issue of being stuck in flash mode on some USB power supplies
16:34 - demo of YouTube statistics counter booting as it should do
17:15 - examining reset circuit and further investigation. Trying various component swaps
27:04 - giving up, getting pissed off and smashing the whole project up with my hammer
27:53 - conclusion and burning them on the fire

#esp8266
#wemosd1mini