Hi
I have faced similar problem with other hardware (mine is SmartGPU2 3.5")
and I am still not able to boot up the screen but I have made many steps, it might help
1- make sure the input voltage to your device is correct
2- make sure you have the right libraries to operate the screen
3- read the document sheet of your device and connect the wires based on it.
hamzehhirzallah:
Hi
I have faced similar problem with other hardware (mine is SmartGPU2 3.5")
and I am still not able to boot up the screen but I have made many steps, it might help
1- make sure the input voltage to your device is correct
2- make sure you have the right libraries to operate the screen
3- read the document sheet of your device and connect the wires based on it.
BTW Trade Spotting are the ebay arm of SAINSMART and the ebay prices are higher than buying direct !
Have used about 24 screens and shield some times direct but i generally attach screen by ribbon to ensure access to the other pins is simple
Had only 1 failure, UTouch is quite quirky on this display if you email Auther and says Sainsdmart he tells you in no uncertain tone no support your own your own
UTFT works on solution but I have wrappered a class arround it to create in my opinion a nore consistent and defined interface
The UTouch lIbrary in my view uses a slightly odd method ..
I used a logic analyser to review the Texas Instrument chip used for the screen, this showed the best option seemed to be to attach the IRQ to a pin on arduino as an ege triggered interrupt. rather than use the polll techniues and read while low.
The spec on the chip also highlighted that although its 12 bit resolution to ensure next value availability you should clear the buffer register by clocking 16 bits through, from memory the UTouch library only does 12
You tend to get a ghosting interrupt generated at removal of touch which if your polling will cause extra invalid readings.
4 I run a moving average on data during a touch event.
Calibration is difficult on smaller displays if you google cailibrartion algorithms for TFT touch, the matrix solution always comes out best but
/// a.. On 3,2 its a bit overkill
// b. The maths is difficult to program
The UTouch Library solution is fair, but holding the pointer still whilst sampling for a series of locations I find difficult, my customers founmd impossible.
Rewrote the calibration to cycle defined points round screen to acieve am average Y for TOP, BOTTOM and average x for LEFT, RIGHT with that and some simple maths can scale any touch sample read to be position on screen
Currently can specify down to 8 x 8 Icon on screen and with stylas touch detecy position. With finger touch use 16 x 16 Icon