Social Things_06 ↓ Third Prototype

Reminder: my prototyping process has lead me to an unexpected path; the path of re-creating a touch pad. I did think of directly buying one, but I wanted to get out from both the aesthetics and the shape which is pretty determined by its manufacturing and standardization – starting with the Apollo Computer in 1982.

Be it touch pads or touch screens – they both work with capacitive sensing.

It is very easy to get started with that kind of prototype with Arduino. Below – I used foil but you can pretty much use any conductive material.

Wiring: I connected (1) wire and (1) 1M resistor to respectively digital pins 3 and 4 directly on the Arduino. Both of them were attached to crocodiles wires holding on to a sheet of foil. I used an 1M resistor for its to only respond by direct touch, but you can use a higher resistor and it will respond by few inches.

LOW TECH TOUCH PAD

Code: With its, I used the Capacitive Sensing library which is great to quickly get it to work ↓↓↓

#include <CapacitiveSensor.h>

CapacitiveSensor cs_4_2 = CapacitiveSensor(4, 2);
void setup()
{
 cs_4_2.set_CS_AutocaL_Millis(0xFFFFFFFF);
 Serial.begin(9600);
}

void loop()
{
 long start = millis();
 long total1 = cs_4_2.capacitiveSensor(30);

 Serial.print(millis() - start);
 Serial.print("\t");

 Serial.println(total1);

 delay(10);
}

By using the Serial Monitor, I could see the numbers going up when – I paused my finger; I paused it long enough; I pressed more than one finger. It is very straightforward, but it seems it needs stable conditions for its to work. There are copper tapes in the studio I can make use of instead of foil – it seems to be better in terms of stability.

It also might be better to switch to the MPR121, as I would be able to use different strips of foil in a easy and stable way. I didn’t use it previously because I thought MPR121 only had an on/off state, but I just need to time up these states according to Nicolas.

I also started to use MAX/MSP with Arduino, here is a simple patch visualizing the datas ↓↓↓

Social Things_06 ↓ Third Prototype

I’m actually thinking to use MAX/MSP to trigger sounds. More on that on my next prototype!

Leave a Reply

Your email address will not be published. Required fields are marked *

Archives