ESP UART pins misnamed on some boards

[dhalbert]

I was helping someone with a PyPortal-using-BLE issue, and it turns out the ESP TX/RX pins on a few Airlift-style boards are labeled only RX and TX, even though they are only connected to the ESP32. This makes them incompatible with the adafruit-airlift library right now without giving different pin names.

This PR adds ESP_TX and ESP_RX names to the existing TX and RX pins, which is upward compatible.

However, I think that it would actually be better to remove the TX and RX names and also board.UART(), since these are not externally available pins.

If you agree, let me know and I'll revise this draft PR. One or two Guides would have to be updated as well.

[ladyada]

@brentru - please take a look at your convenience!

[brentru]

@dhalbert @ladyada

However, I think that it would actually be better to remove the TX and RX names and also board.UART(), since these are not externally available pins.

Agreed! I'm ok with renaming the internally connected pins to ESP_ as well.

One or two Guides would have to be updated as well.

Which guides are effected by this change?

[dhalbert]

This is the one I found so far: https://learn.adafruit.com/adafruit-pyportal/pinouts#step-3020486

[brentru]

May also need to update MiniESPTool examples (https://github.com/adafruit/Adafruit_CircuitPython_miniesptool/blob/master/examples/miniesptool_simpletest.py)

[brentru]

Looks good - uart removed, new ESP_ pins are correctly labelled for esp control.

[dhalbert]

May also need to update MiniESPTool examples (https://github.com/adafruit/Adafruit_CircuitPython_miniesptool/blob/master/examples/miniesptool_simpletest.py)

This looks like it will not need revision because it will just pick up the new names, e.g.:

tx = getattr(board, "ESP_TX", board.TX)
rx = getattr(board, "ESP_RX", board.RX)

[dhalbert]

1 failure is an upload failure, unrelated to PR.

[dhalbert]

I updated https://learn.adafruit.com/adafruit-pyportal/pinouts#step-3020486, which mentions the pin names, and also the sample AirLift BLE program here: https://learn.adafruit.com/adafruit-airlift-breakout/circuitpython-ble#copy-and-adjust-the-example-program-3076274-17. They mention that after CircuitPython 6.0.0, the pin names have changed. Once 6.1.0 is released for real, I can remove those caveats.