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.
For a safe connection of the e-paper displays, please refer to EPD Handling and ESD Precaution.

​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).
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Sketch.ino

    









					
									

		
	






	

		
			

				
					
						


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



					
										
					
						



	

    

        
hV_Configuration.h

    

    

        

    









					
									

		
	





Hardware





Picture







Raspberry Pi Pico with RP2040 Pico board package connected to EXT3-1 and EXT3-Touch





Picture







Raspberry Pi Pico with RP2040 Pico board package connected to EXT3



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. 



					
										
					
						



	

    

        
Sketch.ino

    

    

        

    










	

    

        
hV_Configuration.h

    

    

        

    









					
									

		
	





Hardware





Picture







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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, 27 Jan 2023