DS controller: Cap sensors. Need a spot of help.

Want to just shoot the breeze? Forum 42 is the place!

Moderator: Moderators

Post Reply
yuyuyami
Posts: 5
Joined: Sat May 05, 2007 8:55 pm

DS controller: Cap sensors. Need a spot of help.

Post by yuyuyami »

I've been playing with the idea of using 4 capacitor sensors to make a "primitive touch screen like device" that I could use for my DS. I already have my DS modded with 4 directional wires + a grounding wire and have a detachable analog stick to go along with it. It works perfectly, so the DS part of this won't be a problem, it's already done.

Hopefully someone who reads this will know about cap sensors and how they work.

Here's the image file that shows how I would arrange the cap sensors and what the device would look like, of course without the interpreter that would translate the input to emulate analog input if so desired, or just make it digital. I will need a bit of help designing the interpreter:

Image

Let me explain how it works. In the top part of the png, the quarter circle looking thing is the cap sensor. The yellow is the shielding, the red if the charged plate and the blue is the neutral plate. The swirls are springs that are placed on each cap sensor, and then the cap sensors are arranged into a circle. Next, the light blue thing is a plastic shield that will be hinged from the neutral plate and will be attached to the springs. The idea is that if you press on it close to the center of the entire device, it will barely dip into the dielectric and disrupt the electric field caused by the cap sensor only a tiny bit, and if you press on the plastic farther away from the center of the device, it will dip even more so into the field. The green thing is just something to go in the center so that the surface of the primitive touch screen is smooth when not being touched.

Where I will need help is in making and programming the mini-computer that will translate the input. To simulate analog input, the more the plastic disturbs the electric field, the faster the frequency that the mini-computer will complete the corresponding circuit so as to cause the short to make the DS register a button press. The frequencies will range from not registering a press at all to only a press with no breaks in between.

Like so:

Press break break break press break break break press. That would be one example of a frequency.

Another is:

Press press press.

Another is:

Break break break.

There will also be a switch to make the primitive touch sensor entirely digital in its input to the DS.

I also would like to have the mini-computer made in such a way that in case the dielectric (the air in this case) has a massive change, say, in water content, then the user can run a calibration. I'm thinking that it will work by comparing the non-touched results of the primitive touch screen with the results of the touch screen pressed to the max on each cap sensor.

Soo....

Any ideas?
Last edited by yuyuyami on Sat May 05, 2007 10:19 pm, edited 1 time in total.
Skyone
Moderator
Posts: 6390
Joined: Tue Nov 29, 2005 8:35 pm
Location: it is a mystery
Contact:

Post by Skyone »

I think I understand all the electronics now, but I can't see how such a thing would simulate the touch pad. Couple questions;

1) Why do you want to recreate the touch pad?

2) Are the capacitors' charges going to simulate the "x,y" of the touch pad?

Either way, great design and it sounds like a good idea! I can't wait to see how it goes. :)

-Skyler
yuyuyami
Posts: 5
Joined: Sat May 05, 2007 8:55 pm

Post by yuyuyami »

Not recreate the touch screen, I'm using this as a solution to the DS's lack of analog stick. With the previously mentioned analog stick that I modded to my DS, I was able to play some games, like Mario 64 DS quite well. In fact, I hated that game on the DS till I did my analog mod, now I love it. I'm now trying to get a much better DIY solution.

The way it would emulate analog is that it measures how much the plastic changes the dielectric (space between the two plates), and thus, how much it changes the capacitance of the two plates. It disrupts the electric field the two plates have, and the mini-computer that I DO need help designing and making, would translate that into a frequency of completing the specified circuit with the ground and the specified wire.
khaag
Senior Member
Posts: 2261
Joined: Sat Mar 18, 2006 7:54 pm

Post by khaag »

Can you post some pictures of your analogue mod?
yuyuyami
Posts: 5
Joined: Sat May 05, 2007 8:55 pm

Post by yuyuyami »

I do have a video. Let me copy/paste it from Acidmods forums.

Here it is:

http://youtube.com/watch?v=Hp25QHx-Has


But this isn't the focus of this thread, I would like a bit of help designing and making the mini-computer to handle the input and output it to the the DS.
vskid
Senior Member
Posts: 6314
Joined: Fri Mar 25, 2005 8:25 am
Steam ID: vskid3

Post by vskid »

I believe the DS touchscreen is resistive, so why are you using capacitors? You should be using potentiometers. :?
Jamie from Mythbusters wrote:Theres your problem.
Image
Jongamer
Senior Member
Posts: 2151
Joined: Wed Dec 13, 2006 2:43 pm
PSN Username: Geekystig790
360 GamerTag: Mesu Gitsune
Location: Fairborn, Ohio

Post by Jongamer »

*POST REMOVED BY POSTER*
Last edited by Jongamer on Thu Sep 08, 2011 6:17 pm, edited 1 time in total.
Post Reply