[Rpi3] NDS touchscreen

mediamogul

Touchscreen input is usually read as being a pointer device, so it should just work as is. I assume you're wanting to use DraStic, so you should be aware that the current Raspberry Pi version is a very early release and it may only have support for standard mouse input. The Mayflash Dolphinbar in modes 1 and 2 is read as being a pointer device. If that works, a touchscreen should too. It seems like I remember you having a Dolphinbar, but if you don't, I may be able to test it later this evening.

Chuck_B

This post is deleted!

Chuck_B

@mediamogul I don't have a DolphinBar, just an airmouse.
So if you may test it, it would be great

mediamogul

@chuck_b

Sure. I'll let you know how it goes. In the past, I've used DraStic on an android gaming tablet with a stylus and it worked pretty well. I'm curious to see if it's an option here myself.

quicksilver

On a side note, exophase mentioned about a month ago he may open the source for drastic. Cross your fingers!

Chuck_B

@mediamogul Perfect! Thank you so much

mediamogul

@quicksilver said in [Rpi3] NDS touchscreen:

On a side note, exophase mentioned about a month ago he may open the source for drastic. Cross your fingers!

Wow, that's great news.

mediamogul

@chuck_b

Well, I just gave the Dolphinbar a shot and unfortunately it wasn't able to control the cursor. Obviously this isn't conclusive proof that the touchscreen itself wouldn't work, but I suspect that it wouldn't.

reeebs

I tried both with hyperpixel and the official 7” and they work with drastic, meaning that moving the finger on the screen is moving the pen.
unfortunately, in both cases, there is no precision from the point where is your finger and the point where the pen is.
maybe anyone can tell me how to calibrate the touchscreen to work fine and with precision?

mediamogul

@reeebs said in [Rpi3] NDS touchscreen:

unfortunately, in both cases, there is no precision from the point where is your finger and the point where the pen is.

I ran into this same problem with my Android gaming tablet. I was able to get acceptable results using a stylus.

Chuck_B

@mediamogul thank you anyway for trying :)

@reeebs have you tried with a pen similar to nds pen to see if precision gets better?

reeebs

@reeebs have you tried with a pen similar to nds pen to see if precision gets better?

@Chuck_B no, not yet
maybe tomorrow (anyway in a couple of days) I’ll try and then post here the result
(but I don’t expect nothing in particular, as the two positions - the real one of my finger and the one of the pointer - are completely wrong: if I move, it moves too, but when I am in a corner it starts from the center and so on)

mediamogul

@reeebs said in [Rpi3] NDS touchscreen:

I don’t expect nothing in particular, as the two positions - the real one of my finger and the one of the pointer - are completely wrong: if I move, it moves too, but when I am in a corner it starts from the center and so on

That's very telling behavior and explains why the Dolphinbar wasn't recognized. The touchscreen is apparently being read in this case as a standard relative coordinates mouse. If it were being read as an absolute coordinates pointer device, the cursor would snap to wherever it was you touched at. Needless to say, this limitation combined with the wide area required to receive input really hinders precision.