I've been following a guide for setting up an LCD touchscreen, without success. When the screen is plugged into the GPIO pins it just shows a white screen. After all my attempts it remains white.


Type: TFT
Interface: SPI
Touchscreen driver: XPT2046 (drivers supposedly compatible with those for ADS7846)*
Resolution: 320x480
Size: 3.5in
Brand: What brand?
*Used in the linked guide.

The specs appear to be identical to those for this LCD on Amazon (see the specs). The images shown for that product are very similar to what I have (sorry it's in Chinese).

Going through these steps twice hasn't had any effect, and several days' googling has failed me. How do I configure the Pi to use this touchscreen? What other details may be useful?

  • I would follow the instructions in the second link ("drivers supposedly compatible with"), not the first one ("following a guide"); among other things the latter either predates or ignores the device tree "feature" built into kernels for a while now. But first remove whatever lines the former told you to apply to config.txt and cmdline.txt.
    – goldilocks
    Jan 16 '16 at 12:26
  • @goldilocks Thanks; I'll try that. For some reason I didn't think those were full instructions (well, I guess they aren't). I assume I keep step one (fp0 -> fb1), step 2 (enabling SPI), and step 3 (sudo REPO_URI=https://github.com/notro/rpi-firmware rpi-update)? Changes to /etc/modules? I'm not sure what you meant by changes to config.txt; it wasn't mentioned in the linked guide. Sorry for so many questions; I just don't know exactly where those instructions pick up and what they expect to be done already. Re-flashing the SD is totally an option.
    – Nateowami
    Jan 16 '16 at 13:27
  • You might want to edit in your current version of config.txt; the raspi-config would have changed that, but current versions may actually have done some of the same things as what the Thoughtpool guide recommends. Compare what's there to what it says at "Just add the below additional lines" (near the top, what I would say is the first step).
    – goldilocks
    Jan 16 '16 at 13:44
  • @goldilocks dtparam=spi=on was already in /boot/config.txt so I let it be. But I don't know what is meant by the configuration file in the EFI partition. Is that also /boot/config.txt? Anyway, I added it there. Still nothing though; screen still white.
    – Nateowami
    Jan 18 '16 at 5:41
  • Yeah. I dunno if that really counts as an "EFI partition" (it's not generally referred to that way) but that's what's meant. I think probably the important part is the dtoverlay=ads7846.... That may be required on newer device tree enabled kernels which the other, older reference doesn't include.
    – goldilocks
    Jan 18 '16 at 11:03

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