Extending CapSense Inputs

Other Hardware Sensors
1

Hi!

Is there a way to extend the maximum number of capacitive sensors controlled by the
Capsense Library? Because one needs always 2 digital Pins which mades a maximum of
5 Sensors... but nothing else... :frowning: Im thinking of something like the 74hc595 which enables
one to control a nearly infinit number of LEDs!
If it is possible using a certain chip do I have to write my own Capsense Lib when
changing the hardware?

As a base I would like to use the UNO!

Thanks in advance!! :slight_smile:

2

You might find useful stuff in....

In particular, look at the circuit diagram near the bottom... for, say, 4 cap-sense inputs, you only need 5 digital lines. Maybe I mis-understood your post, but if you thihnk you need two lines per input, no, not so.

I hope that's good news?

3

Thanks for your answer!

  1. Does that mean that I only need one signal pin and add lets say 8 reciever pins?

  2. It would be even more cool, when using only 3 pins and read as many
    capacitive sensors as I like! Eg. as I mentiond like the 74hc595 but for inputs. Is there
    a chip for extendting inputs and is able to read capacitive sensors?

4
  1. Does that mean that I only need one signal pin and add lets say 8 reciever pins?...

With 9 pins dedicated, you could monitor 8 touchpads.

  1. It would be even more cool, when using only 3 pins and read as many
    capacitive sensors as I like...

Ummm... not sure how to do this!

You COULD probably multiplex the inputs somehow, but then you will have complex polling software to write. Buy a Mega, and have more inputs than you can use!