Guys,
Using a Picaxe-20M. I've discovered that if an input pin is not connected, then it will test high. i.e.
pin3 = 1.
I need it to = 0 when not connected. The reason? The pin will received PULSINs of varying length, however, the target of these pulses will be manually switched between processors.
When connected to another processor's output pin, the input pin is pulled (if that's the right terminology) negative, and the "pulse" is +, of course.
Diagramatically, wire like this.
A---------------------\
B--------------------------------C
Processor C does the OUTPUT pulses. which get read by INPUTS on processor A or processor B. The switch between the two is manual. ( at the "\" point). The ------------ represents railway tracks. A, B and C prepresent signals (and therefore, each Picaxe-20M).
When OUTPUT C is connected to INPUT A, the INPUT pin on B (not connected) is always High ( = 1). Not good, as it thinks the "pulse" is never ending. I believe the term for "not connected" is "floating". The inputs are currently tied to the + with a 10K ohm resistor.
I know, if I used an appropriate manual switch, I could tie the "floating" input of the "not connected" processor to the negative.
This is not possible, as I'm limited to a particular switch (single pole slide switch), as it is model railway specific, and the clip on switches for underneath the points/turnouts is a single pole slide switch only.
Is there any way I can make an input pin default/work/be = 0 when not connected (floating)? Maybe via a resistor to the negative, still allowing the "pulse" (when switched through to the other processor's output) to pull the input +?
I know what I mean. If you're not sure I'll try and word it differently.
Thanks guys.
Using a Picaxe-20M. I've discovered that if an input pin is not connected, then it will test high. i.e.
pin3 = 1.
I need it to = 0 when not connected. The reason? The pin will received PULSINs of varying length, however, the target of these pulses will be manually switched between processors.
When connected to another processor's output pin, the input pin is pulled (if that's the right terminology) negative, and the "pulse" is +, of course.
Diagramatically, wire like this.
A---------------------\
B--------------------------------C
Processor C does the OUTPUT pulses. which get read by INPUTS on processor A or processor B. The switch between the two is manual. ( at the "\" point). The ------------ represents railway tracks. A, B and C prepresent signals (and therefore, each Picaxe-20M).
When OUTPUT C is connected to INPUT A, the INPUT pin on B (not connected) is always High ( = 1). Not good, as it thinks the "pulse" is never ending. I believe the term for "not connected" is "floating". The inputs are currently tied to the + with a 10K ohm resistor.
I know, if I used an appropriate manual switch, I could tie the "floating" input of the "not connected" processor to the negative.
This is not possible, as I'm limited to a particular switch (single pole slide switch), as it is model railway specific, and the clip on switches for underneath the points/turnouts is a single pole slide switch only.
Is there any way I can make an input pin default/work/be = 0 when not connected (floating)? Maybe via a resistor to the negative, still allowing the "pulse" (when switched through to the other processor's output) to pull the input +?
I know what I mean. If you're not sure I'll try and word it differently.
Thanks guys.