Adafruit Feather M4 Express Manual page 142

Check out the list below for a diagram of your specific board!
Watch out! A common mixup with UART serial is that RX on one board connects to TX on the other! However,
sometimes boards have RX labeled TX and vice versa. So, you'll want to start with RX connected to TX, but if
that doesn't work, try the other way around!
© Adafruit Industries https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51
Circuit Playground Express
Connect 3.3v on your CPX to 3.3v on your GPS.
Connect GND on your CPX to GND on your GPS.
Connect RX/A6 on your CPX to TX on your GPS.
Connect TX/A7 on your CPX to RX on your GPS.
Trinket M0
Connect USB on the Trinket to VIN on the GPS.
Connect Gnd on the Trinket to GND on the GPS.
Connect D3 on the Trinket to TX on the GPS.
Connect D4 on the Trinket to RX on the GPS.
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