2.8" Touch LCD Display Shield for Arduino

I bought this for use with an Arduino UNO and it seems to work perfectly. It took me under 4 minutes to get the demo programs running and test it out. The serial interface makes this a huge improvement over the old parallel touch-screen shields I've been using: It's fast, and it leaves most of the Arduino pins free for other things.

I quickly got the samples running on an UNO. I easily produced a menu module with touch control and reading data from the microSD card on the back of the display. The website description claims "Standard Arduino interface, compatible with development boards like : Arduino UNO, Leonardo, UNO PLUS, NUCLEO, XNUCLEO". The supplied sample programs work perfectly and with snappy screen writes on an Arduino UNO but fail completely on a Leonardo. The samples use inline assembler with no #define for pins and poor comments. The documentation is no help and when I contacted the manufacturer they were unable to provide a sample that works on a Leonardo. A great display for a UNO but useless for other boards.

Works ok as an SPI display, but when it comes to the touch screen bit, falls flat on its face, because I cannot see how it can easily be used from within any software that I can write. The problem is that the touch library whilst it being sufficient to run the coding example is incomplete for general use. Essentially all what is required is a library function that can be called from within an arduino sketch that simply returns screen coordinates when the stylus touches the screen, i.e., interrupt routine function, that can then be returned into the sketch. It's mostly all there in the library, but there is no annotation to help and it all seems to have been a rush job to do the minimum possible to provide a demo. Shame!