Hi mackrackit,

If you are still using the 684 take a look at table 15.5 in the data sheet.
There are two types of inputs, schmit and TTL. One is 0.8 and the other is 2.
Yes still on the 684, I'll have a read of the data sheet tonight.

The Project is coming along, I love these PIC's and what they can do (still frustrated at what I can't do mind) When you start a project it's amazing where things lead and what has to be taken into account, example:

The parent birds fly into the box bringing in food and each time they do so they break the beam and a counter (divide by two as we said earlier) gets incremented. Then as night falls the voltage level on the P0T_Divider rises and when it's dark a pin reads voltage 1 and that days data gets rfpic'ed across. However simple little things to consider, how dark is dark? Is a passing cloud 'dark' enough to make the data be sent prematurely etc...? Things like that.

I've been spending time analysing Bruce's rfpic program to try and figure out just what is going on and how it all works. Plus I've been dabbling with some basic assembler...oh dear

It's a good job I've got until next Spring to get this up and running Also learning to program is a great thing to go over the Winter Months too.

So, slow progress, still loving it.

Dave