Q about esp8266 version

[BartSr]

Hi, years ago I bought a few esp's for interfacing an old OTGW.
But.... I can't find any longer data about e.g. how to flash.
I tried flashjng with switch in 'program mode' but thaf failed after 'preparing... (website TD-er)
Any suggestions?
-Bart

[Ath]

Assuming you have RX and TX connected correctly, you should slide the switch to "Program", then press "Reset" shortly, and start the Flash procedure.
Also be aware that some USB-Serial adapters won't provide enough current for an ESP to run stable, so maybe you can hook it to a more powerful 3.3V power supply instead (and GND of course).

[Ath]

Hmm, looking at the voltage regulator that's mounted on the board (U1), it is possible it needs 5V instead of 3.3V, but you might want to make sure by checking the documentation, or validate what trace the VCC pin is running to

[BartSr]

Ok
rx an tx right connected
lab power supply set to 5.0V
ground of esp connected to ground of pc
switch on esp in program mode
after hooking up esp to pc pressed reset button
blue led responds with flash
then start flashing
fails.....

then I tried keeping reset button pressed during flash
same result

then i made temp connection of GpIO o to ground
same result

any other suggestion?

-Bart

[TD-er]

Just keep in mind that RX and TX should be connected via a 'cross connection'
Thus TX on one side connected with RX on the other side and vice verse.

[BartSr]

sure, have done it many times before (same tx/rx >>usb) but never with this kind of esp. So I must do something wrong. I saw a voltage regulator on this esp so safe to use 5V.
-Bart