Well basically I have a patch that reads samples and each sample is select using TUIO and fiduscial markers. When a new marker is picked it resets the sample. I have 2 samples per fiduscial marker however, one for positive values and one for negative but cannot reset these 2 samples when switching between positive and negative. I'm wondering does anyone know whether I can send out a single bang each time I switch between positive and negative so I can reset these samples? I tried using a bang with the expr~ object I already have in place to sort the numbers when they are coming into PD from an arduino but I had no luck. Apologies if I explained this poorly but I tried my best.

to make your explanations easier to read, i highly recommend the "enter" key occassionally. :0)

i think this is what you need:

[> 0]
|
[change]
|
[sel 0 1]

good luck!

That seems to be what I am looking for I just have to integrate it into my patch thanks!