adafruit-metroM4-to-HUZZAH32.txt

To use CircuitPython on the the Adafruit Metro M4 (http://adafru.it/3382)
with the HUZZAH32 (http://adafru.it/4172), you'll have to connect the two
boards and make a few changes to the esp32spi_simpletest.py code.

First, here are the connections that need to be made between the two boards:

Metro M4     HUZZAH32
--------     --------
   D5    ->     33
   D7    ->     RST
   D8    ->     5
  MISO   ->     23
  MOSI   ->     14
  SCK    ->     18

NOTE: The SPI pins in the Learn Guide
(https://learn.adafruit.com/adafruit-metro-m4-express-featuring-atsamd51/pinouts
are labeled from the perspective of you holding the board with the USB port
facing left.  I got confused trying to orient the board so the chip in the
picture was the right way up.  That picture is from the Grand Central and
the SPI flash is in a totally different location on that board.

Then, in the esp32spi_simpletest.py code, you'll need to change these three
lines:

esp32_cs = DigitalInOut(board.ESP_CS)
esp32_ready = DigitalInOut(board.ESP_BUSY)
esp32_reset = DigitalInOut(board.ESP_RESET)

To be:

esp32_cs = DigitalInOut(board.D8)
esp32_ready = DigitalInOut(board.D5)
esp32_reset = DigitalInOut(board.D7)