Display for particle Muon (~4" 480x800)

Brainstorming
1

Dear all,

Currently I have a 2" Pimoroni display working on the photon 2 using the Adafruit_GFX_RK library. The layout is nice but drawing to the display is pretty slow but maybe because I'm using the software SPI instead of the hardware one, I'm still a beginner with this...

I hope to receive my Muon soon and I would like to attach a good looking display, size ~4" 480x800, and would like to hear from the experts what the best options are these days. Nextion and 4D are mentioned in some posts but I'm not sure how to choose. It should be easy to hook up and be used with particle library. Capacitive touch is nice but touch is not a must.

The idea is to show:

  • Standard things like time and date
  • Some lines and simple shapes
  • Network and power status information
  • Data received by MQTT (power consumption etc.)
  • Graphs that I draw by displaying pixels coloured according temperature
  • Weather icons and temperature

Thanks for your suggestions!

2

SPI-based displays will work fine on the Muon, however:

  • Make sure you are using hardware SPI, because software SPI does not work on Gen 4 (RTL872x: P2, Photon 2, M-SoM, and Muon).
  • Some display drivers are very inefficient, and small changes can make a huge difference.

For example, some display drivers write one byte at a time using SPI which is very inefficient. Modifying the driver to write an entire row using SPI DMA will have a huge increase in performance.

One of the reasons for the smart display recommendation is the slower clock speed and the limited RAM of Gen 2 and Gen 3 devices. Gen 4 devices have a fast CPU and lots of RAM, making using plain displays a more viable solution.

3

You wrote that the photon 2 has no software SPI so the slow performance is probably caused by something else.

I just remembered that the Muon now comes with the Raspberry Pi 5 form factor. Does that means that any shield, if there is a particle library for the display driver, is plug and play?

4

While the hardware for a Raspberry Pi SPI display will fit on the Muon, it will require completely different software drivers since the Muon isn't actually a RPi and has a completely different software architecture. Also note that a display that uses HDMI will not work, since the Muon does not support HDMI.

The Tachyon is also the same form-factor, and isn't a RPi either, but since it's a Linux board it's much more similar to the RPi and it's much more likely that the software will work with minimal changes.