Nintendo DS Screens, Unreliable?

Anyone with experience using the cheap Nintendo DS touch screen replacements, have you noticed the readings to be unreliable? Maybe mine is just a bunk one. The problem is the max values seem to be slightly off in different spots across the top and side. maybe the buss bars inside the screen are slightly crooked?

anyone else notice anything like this?

They are on my official DS touch screen too. Thankfully I am not using it for anything that sensitive. Due to the distance up and along the sides of the screen (for the conductor) they would likely be slightly different in the top right corner...

They aren't brilliant touch screens but have been alright for what I have wanted them for :)

Mowcius

thank you for the reply, i was beating myself up trying to figure out what i was doing wrong before i realized it might just be the cheap screen.

i wonder if larger screens in the 30$ are accurate. does anyone have any recommendations?

thank you for the reply, i was beating myself up trying to figure out what i was doing wrong before i realized it might just be the cheap screen.

i wonder if larger screens in the 30$ are accurate. does anyone have any recommendations?

If you can work out the change in values then you could use the x value to correct (map) and add to the y values accordingly (if the change is linear). Same with correcting the y.

5 wire touch screens are in general more accurate but I am not sure how to use them with an arduino. Maybe someone else knows. I have not got any experience with more expensive screens though. If you put in a calibrartion routine and mao values from that then it would sort out the errors.

Regarding the 0 value you want to send over MIDI, if you look at: http://mnicolato.altervista.org/arduino/ardtouch.htm which I presume is what you used the code from anyway (or somewhere that copied it) then there is boolean touched(); that reads if the screen is touched and sets it to true. You could then use an if command for if it's false to then send your 0 MIDI value...

Mowcius

Just remember that the ADC on Arduini has a little bit of variation in it self.

Analogread() can return different values even if you didn't change the resistance on the device conneted to the anaog pin.

So some small fluctuations in readings should always be expected, if possible it is best to do a series of readings and then use the average value.

Just remember that the ADC on Arduini has a little bit of variation in it self.

Analogread() can return different values even if you didn't change the resistance on the device conneted to the anaog pin.

So some small fluctuations in readings should always be expected, if possible it is best to do a series of readings and then use the average value.

On touch screens like this it is a standard variation, not small variations in each reading.

Mowcius