Help needed with MPR084

Forum 2005-2010 (read only) Hardware Interfacing
1

I need some working sample code to get me started with the MPR084 capacitive touch sensor IC.

I googled, tried every piece of code I saw, but I can get no reliable response from the little bugger.

2

tried every piece of code I saw, but I can get no reliable response

That suggests to me that you have hardware problems rather than software ones. What is your setup? Are you using a PCB? You need to in order to get a consistent response from a capacitive touch sensor.

3

Yes, it is all on a small PCB with connectors, I have included the schematic.
http://files.jeelabs.org/2010/02/Screen-shot-2010-02-14-at-12.05.27.png
The sensorplate I use is a piece of copper foil of 3 x 1 cm connected thru a short wire to pin 3 (E1 of MPR084) of SV1. A short cable connects PORT1 to my Arduino.

I just need an example how to configure the registers to activate one or more sensors and how to read them.

4

Anyone?

5

This is an I2C device so you must connect it to the arduino's I2C pins (A4 & A5). You also need a 4K7 pull up resistor on each of these lines. Have you done this?

Then look at the I2C tutorials to see what libraries you need.
http://www.arduino.cc/playground/Learning/I2C

Then follow the data sheet to set up the registers.

This is a 3.6V device I hope you are not using it with a 5V arduino.