Grounding/ungrounding a single wire
#1
Posted 21 October 2011 - 06:08 PM
#2
Posted 21 October 2011 - 10:22 PM
- Connect anti-static foam directly to the display of an iPad (the anti-static foam is the stuff that IC's are normally mounted on when shipped)
- Connect a wire from Ground to the anti-static foam
- Trigger the Ground connection on and off
This makes the Netduino "touch" the iPad touchscreen. I've already tested this simple scenario and it works, but I have to physically touch the wire to Ground and remove it. I need some way of doing this with Netduino programming.
I have an iPad drums application, and my current idea is to make an automatic drum sample controller with the Netduino;
- Connect anti-static foam to each drum kit point on the iPad display
- Connect separate Grounds for each wire
- Trigger these wires individually so I can press each drum-kit item separately (high-hats, cymbals, bass drum, etc.)
- Record and play back the drum sample on the Netduino, sort of like one of those pianos that plays automatically.
This would also allow me to trigger the drum kit with other materials by using pressure sensors. Ultimately, I could use regular drum sticks on other materials to play the electronic drum kit on the iPad.
The problem I'm solving with this: the iPad display is small, and obviously I cannot smack real wooden drum sticks directly onto the iPad display, so I have to use my fingers to play the drum kit, which is not true to a real drum set, and it is cumbersome.
This would open up the ability to create a small electronic drum kit that could be played with real drum sticks. All the sounds are already there on the iPad; I just need to implement the electronic connections to "touch" the iPad display.
What do you think? Dumb idea? Cool idea? Useless idea?
Has anyone done anything like this before? Any tips?
Thanks!
#3
Posted 22 October 2011 - 02:21 AM
Just so you know what I need to do:
- Connect anti-static foam directly to the display of an iPad (the anti-static foam is the stuff that IC's are normally mounted on when shipped)
- Connect a wire from Ground to the anti-static foam
- Trigger the Ground connection on and off
This makes the Netduino "touch" the iPad touchscreen. I've already tested this simple scenario and it works, but I have to physically touch the wire to Ground and remove it. I need some way of doing this with Netduino programming.
I have an iPad drums application, and my current idea is to make an automatic drum sample controller with the Netduino;
- Connect anti-static foam to each drum kit point on the iPad display
- Connect separate Grounds for each wire
- Trigger these wires individually so I can press each drum-kit item separately (high-hats, cymbals, bass drum, etc.)
- Record and play back the drum sample on the Netduino, sort of like one of those pianos that plays automatically.
This would also allow me to trigger the drum kit with other materials by using pressure sensors. Ultimately, I could use regular drum sticks on other materials to play the electronic drum kit on the iPad.
The problem I'm solving with this: the iPad display is small, and obviously I cannot smack real wooden drum sticks directly onto the iPad display, so I have to use my fingers to play the drum kit, which is not true to a real drum set, and it is cumbersome.
This would open up the ability to create a small electronic drum kit that could be played with real drum sticks. All the sounds are already there on the iPad; I just need to implement the electronic connections to "touch" the iPad display.
What do you think? Dumb idea? Cool idea? Useless idea?
Has anyone done anything like this before? Any tips?
Thanks!
Very cool idea, and a unique way of triggering the touch screen!
You should be able to just connect the wire to a GPIO, and configure it as a Tristate port, leaving it open. Then to trigger it set the port to low which will be your ground.
Try it on a breadboard. If that doesn't work you would probably need to use a relay. I doubt a transistor would work because there's not a complete circuit for the base to emitter. So it may also be true for the GPIO port that you won't get a connection to ground this way. But it can't hurt to try.
#4
Posted 23 October 2011 - 02:00 AM
#5
Posted 23 October 2011 - 02:48 AM
Netduino touches my iPad.
See video action here: Netduino triggers iPad Drums. The ticking sound is not a metronome- it is the 9vdc relay I'm using to open and close the Ground.
I also notice that if I increase the speed, sometimes it misses hits on the touchscreen. Does anyone know why? Other than the anti-static foam, should I use other materials to get a more reliable contact?
#6
Posted 23 October 2011 - 02:52 AM
A relay works. The problem is that the relay contacts are not going to last very long if I use this method. Can anyone think of any other way to do this??
Netduino touches my iPad.
See video action here: Netduino triggers iPad Drums. The ticking sound is not a metronome- it is the 9vdc relay I'm using to open and close the Ground.
I also notice that if I increase the speed, sometimes it misses hits on the touchscreen. Does anyone know why?
Nice job, that's awesome!
Next thing I'd try would be a SSR (Solid state relay), something like this: https://www.jameco.c...ductId=1583068
As far as the misses, make sure your pulse duration is long enough to fully charge the coil of the relay. You may need to add some code that ensures a minimum duration on the output pulse.
But with the SSR, you may not be quite as constrained by the timing.
#7
Posted 23 October 2011 - 01:58 PM
Nice job, that's awesome!
Next thing I'd try would be a SSR (Solid state relay), something like this: https://www.jameco.c...ductId=1583068
Thanks again Darrin! My local shop doesn't carry SSR's, but they do have 5V Reed Relays, so while I'm waiting for the SSR's, I'll give them a try.
#8
Posted 24 October 2011 - 09:47 AM
How about JFET or MOSFET transistor?Can anyone think of any other way to do this?
#9
Posted 04 February 2012 - 10:32 AM
#10
Posted 04 February 2012 - 05:28 PM
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users