I'm having issues using the digital inputs of an Arduino Duemilanova into Pure Data.

I'm using a photodiode with a 1M potentiometer configured like this:

Arduino +5v -> Cathode-[Photodiode]-Anode -> Arduino Digital In -> 1M potentiometer -> Arduino Ground

(The digital in is connected to both the photodiode anode and the 1M potentiometer)

And then I have the pduino standard firmata 2.1 loaded into the Arduino.

Now this kind of works. But I'm trying to use the photodiode as a sort of tachometer. Every time light hits the photodiode, send a 1, no light: 0. This works if I do it slowly. But the faster I flicker the light on and off the photodiode, the digital toggle box doesn't register many or even most of the flashes, YET the TX LED on arduino keeps flashing perfectly, so it seems the data is being sent. It just seems like somehow the connection between the arduino and PD, is somehow choking. Any suggestions?

http://www.pdpatchrepo.info/hurleur/cHruR.png

Hello, sfprint:
Get an oscilloscope to see if flickers are really the amount you see on the Arduino led or there are many more, or less. Electrical switches have electrical bouncing, so why wouldn't your sensor? Second thing: Arduino seems to be sending the data. Is it? You may want to use something like wireshark [0] [1] to check the communications inside your computer. I hope this program can sniff into it. I hope this helps.

Sumidero

[0] http://www.wireshark.org/
[1] http://wiki.wireshark.org/