The PicoIO64 adds 64 3.3V I/O pins (5V tolerant) to the Raspberry Pi Pico using four 16-bit XRA1403 SPI I/O Expanders coupled with an 800mA 3.3V regulator. The I/O can be used for front panel LED, buttons interfaces, etc.

The I/O is arranged in two banks each with two 16-bit SPI expanders A/B and C/D, each bank has it's own SPI connection, IRQ, RESET and individual IC chip selects (CSA/CSB and CSC/CSD). Splitting the banks like this allows each banks SPI interface to be controlled using a dedicated core of the RP2040/RP2350 at up to 26Mhz.

The GPIO connections are documented on the underside of the PCB are shown in the table below.

The XRA1403 I/O expanders are fully featured, each of the I/O pins can be configured as push-pull output (optional three-state mode), input (optional polarity inversion, optional ~100k pull-up resistor) and a multitude of interrupt options (rising/falling edge, filters, etc.).

The I/O expanders can source/sink a maximum of 25mA per pin, up to 100mA per bank of 8 pins (0-7, 8-15) and overall the IC can source 160mA over all 16 pins.

A library to use the XRA1403 I/O expander with CircuitPython can be found on Github.

Models

• Self Solder Kit - PicoIO64 PCB and four 2x20 headers supplied, self supply Pico/Pico2 [W], self solder.
• *Assembled * - PicoIO64 with soldered 2x20 headers and socket for a Pico/Pico2 [W] with headers.

Please ensure your address is full and correct before placing an order and be aware I'm unable to use some shipping methods to PO boxes.

Deliveries to the USA are sent using RoyalMail PDDP (Postal Delivery Duties Paid).