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Touchscreen Setup

Posted: Fri Feb 05, 2016 2:40 am
by bfuller
I have purchased a 7" HDMI and touchscreen from ebay for my new Pi 2 B. ... EBIDX%3AIT

The HDMI video is working but I think I still need to play with some parameters as the displayed text quality is not real good.

My problem is getting the touch screen working. This unit has an SPI interface and I have wired it up but can't seem to get Pi to recognise the existence of the touch input. This subject may have been covered before but searching last just left me confused.

I have enables the SPI in the config file but there is more it seems. Some sort of driver. The display uses the XPT204 chip for the resistive matrix driver.

Re: Touchscreen Setup

Posted: Mon Feb 08, 2016 1:07 am
by bfuller
Attached I have the pinout of the touch part of the board.

Should MISO and MOSI be directly connected, or crossed over? (based on a Pi -- Arduino diagram, I think direct)
Do I need the T_BUSY connection?
What do I do with the T_IRQ connection

And what driver do I need to make this whole thing work please?


Re: Touchscreen Setup

Posted: Tue Feb 09, 2016 5:56 am
by bfuller
Well, I have discovered that the 2046 controller is ADS7846 compatible.
I have loaded the ads7846 overlay and confirmed it is there with lsmod command.
But, still no go. I'm stuck