How do I check the status of an output?

edbfmi1 · Joined: 18 Jul 2006 Posts: 98

I am converting some very old code that was written years ago in Microchip's now obsolete 8-bit C-Compiler.

In this old code I would have an ouput that will be turned off and on during the course of operation.

Depending on the state of this output I will do other things.

I would define the output as follows

ckielstra · Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands

The function input_state() will test the current voltage at the I/O pin without changing the TRIS setting.

edbfmi1 · Joined: 18 Jul 2006 Posts: 98

Thank you! That is what I was looking for.

meereck · Joined: 09 Nov 2006 Posts: 173

why is in my old manual for the compiler v3 written the following for the "input_state" function:

Ttelmah · Guest

The current manual, has it as:
"Bit specifying whether pin is high or low. A 1 indicates the pin is high and a 0 indicates it is low", then:
"This function reads the level of a pin without changing the direction of the pin as INPUT() does."

Which is exactly what is wanted.

In fact, if you look in the 'readme.txt' with your compiler, it should have the updated definition. The manual was wrong for the first few versions after the function was launched.

Best Wishes

meereck · Joined: 09 Nov 2006 Posts: 173

you are absolutely right.
thanks, M.