I have an input stream of 0 or 1 values (sensor input). I want a single bang only when the value changes from 0 to 1. In something like Python I might do it like this

newvalue = sensorInput()
if newvalue==1 and oldvalue==0:
bang()
oldvalue=newvalue

but how do you it in Pd?

or another way of putting it, I want to trigger only on the rising edge of the square wave pulse.

I've been trying different convoluted things with spigot, oneshot, expr, etc., but I still get this continuous flow of bangs no matter what. I thought [threshold] would do it, but I can't get that object to do anything at all, and the help example doesn't do anything either.

thanks for any help, this is tying my brain in a knot.

[onebang]

input
|
[t f f]
X // what this does is compare current value with previous value
[> ]
|
[select 1]
|
bang on rising edge

that's a better way, and vanilla compatible too