USB to serial UART interface – use a nodeMCU prototype board to flash a TYWE2S (ESP8285)

I was trying to flash a TYWE2s chip ESP8285. Bought an FTDI FT232R chip off amazon, two for something like $15… not realizing that I could use a ESP8266 nodeMCU prototype board to do it.

Such a simple hack. You may not even have noticed that there’s an “EN” pin. Well, there is… look at the pinout for the nodeMCU… when it’s free, the esp8266 is enabled. Short it to ground, and it’s disabled.

Now that’s the key, disable the chip, but the onboard chipset that helps with prototyping are enabled. So… that means the the TX and RX on the prototype board are still active and available to repurpose.

So, to flash an ESP8285 (TYWE2S), we’re going to do this:

  • DO NOT PLUG IN THE nodeMCU yet.
nodeMCUTYWE2S
TXTX
RXRX
3.3V3.3V
GNDGND
ENGPIO – 00
  • Now power up the nodeMCU by plugging in the USB.

If you wired everything correctly, and in the same order for powering up. You’re going to be fine.

esptool.py will flash the ESP8285 on the TYWE2s chip via the nodeMCU usb serial.

This procedure should work for the TYWE3S chip as well… but I haven’t tested this. This general procedure will work for all chips…

NOTE: TX to TX, and RX to RX are not swapped in this case, because we’re hijacking the prototype board… on the board itself, it’s already cross labelled.

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