TD-er wrote: ↑16 Jun 2021, 11:34
Fact is that those later boards (also the Lolin D1 mini you linked) do have a voltage regulator which is far less powerful compared to the original (original as in "rev1") Wemos D1 mini boards.
As you can see in the image, the voltage regulator is this 5-pins SOT-23 chip next to the pin labels "D8" and "D7"
Especially those boards without a shield covering the ESP differ a lot per board with respect to stability.
Even modules which appear to be from the same batch, may look completely different when looking at stability.
I know components do have some tolerance, especially capacitors have a reasonable high tolerance in true capacity.
So maybe it is just a matter of having a design with component choices too close to the absolute minimum. If parts do have a tolerance on the negative side, the whole design becomes unstable.
I do understand that a right design is necessary for a stable working ESP-board. So if this board doesn't work, I would have throw is away.
But this board works very stable with the builds mega-20190226 and older. So something must have change in the build that maybe asks more from the components why it get's unstable.
Also those boards, without shield over the ESP, have been reported to experience issues when sending at max. TX power.
That's why I asked it again. But now you mention it, you did indeed check in a lot of steps to see if it has any effect.
N.B. the issue with max. TX power wasn't related to power delivery, but more about the RF signal flipping bits inside the ESP causing crashes.
I have tried to put the package-foil in where the ESP is delivered, to use as a shield by folding it, and just lay it over the ESP8266EX-chip, not blocking the antenna. But also that did not solve the problem.
As far as I can see now, the problem starts when the ESP switches from AP tot STA mode. As long as it is in AP mode it works like designed..
As I suggested, would you like me to send you one? So you can experiment with it?