Connecting the EXT3 to the Raspberry Pi Pico

Scope

This configuration has been tested successfully against

the Raspberry Pi Pico for the screens up to 12.20" included thanks to the large RAM capability
with the arduino-pico from Earle F. Philhower (recommended) or the ArduinoCore-mbed from Arduino (not recommended).

Large screens may require an external power supply for peak current during refresh.

With arduino-pico from Earle F. Philhower (recommended)

Software

The recommended board package is arduino-pico from Earle F. Philhower.

On the main sketch, set the board to boardRaspberryPiPico_RP2040, corresponding to the pins defined in the hV_Configuration.h file of the ePaper_EXT3_Basic_Library (link 1, link 2).

The main differences are about the location of the pins for the SPI and I²C buses.

Hardware

With ArduinoCore-mbed (not recommended)

Software

On the main sketch, set the board to boardRaspberryPiPico_Arduino or boardRaspberryPiPico_RP2040, corresponding to the pins defined in the hV_Configuration.h file of the ePaper_EXT3_Basic_Library (link 1, link 2).

Notes

During the tests, I faced some difficulties with the SPI pins on the Arduino core for mbed 2.0.0 version. The newer 2.1.0 version seems to have solved the issue.

Large projects fail to run with the ArduinoCore-mbed board package but succeed with the arduino-pico board package.

See the issues Raspberry Pico SPI and I2C pins #194 and RPI Pico: LED blinks 4 long, 4 short, then again #3#6.

Additionally, the Segger J-Link programmer-debugger experiences issues with mbedOS when debugging against the Pico.

Hardware

Options

Large screens 9.7" and 12.2" require panelCSS to be defined and connected.

If the second memory is populated on the EXT3 board, flashCSS needs to be defined and connected. The library will keep flashCSS HIGH to avoid any interferences with the other devices connected to the SPI bus.

Posted: 22 May 2021
Updated: 24 May 2021, 24 Aug 2021, 09 Sep 2021