ESP8266 Community Forum

- Wed Mar 03, 2021 10:29 am #90684 Hi all

Obviously new to this so please help if possible:

Just got a ACM ESP8266 SMD BREAKOUTBOARD R2 like the one in the link below:
https://www.electrodragon.com/product/e ... ter-board/

Soldered the ESP8266 ESP12F onto it (the one in the link below:)
https://www.pishop.co.za/store/esp8266- ... egory_id=0

but can't seem to find any info on the pins or how to connect it to a USB to TTL to program it (the one in the link below:)
https://www.communica.co.za/products/hk ... 6110446665

Thanks.

Kind regards
Niel

- Thu Mar 04, 2021 5:55 am #90701 Just out of interest: why did you opt to solder your own development board instead of just buying one (which even would be cheaper and ready for use with built in USB -> UART convertor)?

Anyway: You'll have to power your board with 3.3V (not 5V, the ESP will die if you do) at at least 350mA (preferably more); your USB-UART convertor will not be able to supply this.
After that connect the TX of the USB convertor to the RX (GPIO3) on the ESP and RX of the USB convertor to TX (GPIO1) on the ESP.

Please note that the USB-UART converter you're linking to appears to use 5V digital levels, so you'll have to put a resistor divider between the TX line of the convertor and RX line of the ESP.

Resistor.png

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Assumption is the mother of all f*ckups. At least: that's what I'm assuming.

- Thu Mar 04, 2021 6:55 am #90702 Hi QuickFix

Thanks for the reply.

1. They only had the ESP12F chip at the shop I went to so bought what i could get. I could wait 2 weeks and then get a board like you mentioned but went the difficult route and thought i might learn something along the way.

2. The adapter board already has a 5v to 3.3v converter. But it also has a 3.3v pin. But on the limited info i could find on the web it said that the board needs to be powered with 5v only and that the 3.3v pin is an output and not an input to power the ESP12F.

https://www.communica.co.za/products/ac ... utboard-r2

3. And lastly the PL2303 USB to TTL module is no longer supported by Win 10 hence i'm battling with getting that to work. I can downgrade the driver and then it works but after a few minutes windows installs a new driver for it and it goes back to saying "not supported".
It has 5 pins:
3v3
TXD
RXD
GND
+5V

- Fri Mar 05, 2021 8:23 am #90714 Looking at the data sheet of the PL-2303HXD chip used I suspect the 'spec' saying it is 5V digital is misleading.

It looks like its natural output/input levels are 3.3V and if this is correct then one can connect direct to the esp without voltage dividers. The way to double check is to just plug the board into a USB and measure the voltage between its TX pin and 0V. If that is around 3.3V then don't use a voltage divider.

The native 3.3V supply from the board has limited current output and will certainly NOT power the esp and so do as suggested and use a separate 3.3V supply.

I hack my USB adapters to isolate the 3.3V output pin and then connect it to a 3.3V regulator fed from the USB 5V supply to avoid the need for a separate supply. This does rely on the USB 5V being reasonably solid but I have not encountered any difficulty with regular PC ports.