User Manual

thought this was neat so we made sure all those pins were available. Here are the PCC pins (left) and the Metro M4

pins it's mapped to. Unlike other peripherals, you cannot mux these signals to other pins!

DEN1: MOSI

DEN2: SCK

CLK: MISO

D0: D13

D1: D12

D2: D10

D3: D11

D4: D9

D5: D8

D6: D1

D7: D0

D8: D5

D9: D6

QSPI Flash and NeoPixel

As part of the 'Express' series of boards, the Metro M4 Express is designed for use with CircuitPython. To make that

easy, we have added two extra parts to this Metro M4: a mini NeoPixel (RGB LED) and a 2 MB QSPI (Quad SPI) Flash

chip

The NeoPixel is connected to pin #40 in Arduino, so just use our NeoPixel library (https://adafru.it/dhw) and set it up as

a single-LED strand on pin 40. In CircuitPython, the NeoPixel is board.NEOPIXEL and the library for it is

here (https://adafru.it/wby) and in the bundle (https://adafru.it/uap). The NeoPixel is powered by the 3.3V power supply

but that hasn't shown to make a big difference in brightness or color. The NeoPixel is also used by the bootloader to

let you know if the device has enumerated correctly (green) or USB failure (red). In CircuitPython, the LED is used to

indicate the runtime status.