General • Re: Multiple devices on the SPI bus

For the TFT/Touch needing more than one set of SPI connections,

The fact that there are 2 connectors does not imply that you shall use different SPI ports.

Well, the fact that there are 2 connectors, and that the clock pins for the display and touchscreen aren't connected (in fact, you can see from the traces on the rear of the board that the touchscreen SPI pins that the two bus connections are separate) means that you will or not if you use PIO instead.

However, I take the point, and for once I trust the information I have on the board, which says that the two are separate.

In this case using PIO means two things - firstly that I can use SPI0 for the Wiznet device, and secondly, the connections for the display and touchscreen can all be on the same side of the Pico (the left as you look at it from above with the USB port at "12 O'Clock". This latter point means the board should (in theory) be easier to route.

The display is an Aliexpress sourced 2.8" TFT SPI marked "KMRTM28028-SPI" on a red PCB (which also has an SD card slot, using another set of SPI pins, that I am not intending to use anyway...) with an ILI9341 and XPT2046 as display/touch controllers respectively.
The touch isn't great, but plastic styli were supplied with the batch I got, which helps.

The other one has fewer pins (and no SD card slot), and is a 2.4" display whose only markings are pin labels and a legend reading "2.4 TFT_LCD 240x320 RGB TOUCH". Can't remember where they came from (probably AliExpress again). In this instance, the SPI interface has to be shared between the display and touch (which again, are ILI9341 and XPT2046).

Over the years I collected few different types of displays, but I like the 2.8" variant because of the screen size.

Statistics: Posted by SteveSpencer — Fri Nov 21, 2025 9:52 am

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