Can I add a cheap 3.5" LCD that is using the GPIO on the Raspberry Pi 4 while still using the HDMI out?

  • Yes, that should be possible.
    – Bex
    Apr 2, 2020 at 10:16

1 Answer 1


There seems to be three type of devices on the market:

  1. Screens that replace the HDMI output at kernel level and act as a replacement screen for fitting in a case
  2. Screens that connect via HDMI and a little jumper cable. I'e not seen a Pi 4 version but you may be able to get one that allows HDMI 0 to be normal and HDMI 1 to drive the screen (or the other way around)
  3. Screens that connect over I2C bus and need programming to output data.

Of the three, the last one gives the most flexibility as you can use the HDMI as normal (on any version of the PI) BUT you need to write the programs or find some that can handle this.

  • I think i ordered #1 option, saw the HDMI version and considered it but using a case that also acts as a heatsink needed to also get a gpio extender so it won't fit.
    – Iakovl
    Apr 1, 2020 at 18:35

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