The main processor chip is the Espressif ESP32-S3 with 3.3v logic/power. It has 8MB of Flash and 2MB of RAM.

The ESP32-S3 comes with WiFi and Bluetooth LE baked right in, though CircuitPython only supports WiFi at this time, not BLE on the S3 chip.

There is a 2x8 pin HUB75 plug connector on the reverse side that plugs directly into the HUB75 port on your RGB Matrix. The socket itself is 2x10 so that it fits snug and lined up in a 2x8 IDC socket. Otherwise its easy to get it 'off by one'

There is also a 2x8 pin HUB75 socket connector on the component side that allows you the option to instead connect a 2x8 IDC cable to your RGB Matrix.

There are +5V and Ground M3-threaded screw terminals on either side of the HUB75 connector. These provide power to the RGB Matrix.

If you would like to power the RGB Matrix with external power, we recommend disconnecting it from here and providing power directly to the matrix.

These terminals were designed as outputs ONLY - power from the USB port connects directly to these pads, so you should power from USB and then connect the matrix power inputs to these terminals.

While it's technically possible to power the MatrixPortal through here, we strongly discourage that because plugging anything into the USB port at the same time could result in damage.

The MatrixPortal S3 includes a LIS3DH Triple-Axis Accelerometer. The accelerometer is connected via the I2C bus.

Please note the address of the accelerometer is 0x19 not 0x18 which is the default in our libraries.

There is a 4-pin Stemma QT connector on the left. The I2C has pullups to 3.3V power and is connected to the LIS3DH already.

In CircuitPython, you can use the STEMMA connector with board.SCL and board.SDA, or board.STEMMA_I2C().

3V is the output from the 3.3V regulator, it can supply 500mA peak.

GND is the common ground for all power and logic.

RESET is the Reset pin. Tie to ground to manually reset the ESP32-S3.

Tying BOOT to ground while resetting will place the ESP32-S3 in ROM bootloader mode.

If you'd like to do lower level debugging, we have the ESP32-S3's TXD0 debug pin exposed to view messages.

To read, you would connect a Serial UART cable's Receive connection here and the cable's ground connection to the GND pin. 

The TXO pin and RXI pin are for serial communication with the ESP32-S3 microcontroller and can be used to connect various peripherals such as a GPS.

The RXI pin is attached to board.RX and Arduino 8 and the TXO pin is attached to board.TX and Arduino 18.

Both of these pins can be used for digital I/O.

On the bottom side towards the right, there is a connector labeled A0. This is a 3-pin JST analog connector for sensors, NeoPixels, or analog output or input.

For the JST connected, there is a jumper above that can be cut and soldered to use 3V instead of 5V.

Along the bottom there are also pins labeled A1 through A4.

All of these pins can be used for analog inputs or digital I/O.

There are two LEDs on the board controllable through programming.

There is the RGB status NeoPixel labeled "STATUS". It is connected to board.NEOPIXEL or Arduino 4

As well, there is the D13 LED. This is attached to board.LED and Arduino 13

There is one USB port on the board.

On the left side, towards the bottom, is a USB Type C port, which is used for powering and programming both the board and RGB Matrix.

There are three buttons along the left side of the MatrixPortal S3.

The reset button is located in the top position. Click it once to re-start your firmware. Click it again while the NeoPixel is Purple to enter bootloader mode.

The up button is located in the middle and is attached to board.BUTTON_UP and Arduino 6.

The down button is located on the bottom and is attached to board.BUTTON_DOWN and Arduino 7.

The up and down buttons do not have any pull-up resistors connected to them and pressing either of them pulls the input low.

The boot button is located between the up button and the Microcontroller. Hold it while pressing reset to enter ROM Bootloader mode.

This jumper is used for use with 64x64 matrices and is either connected to pin 8 or pin 16 of the HUB75 connector. Check your matrix to see which pin is used for address E.

You can close the jumper by using your soldering iron to melt a blob of solder on the bottom solder jumper so the middle pad is 'shorted' to 8. (This is compatible with 64x64 matrices in the Adafruit store. For 64x64 matrices from other sources, you might need to use 16 instead, check the datasheet of your display.)