Phil Tilson has prepared these diagrams. Thanks Phil!

Phil writes...

Just wanted to let you and others know that the PIC arbiter is easy to construct, the software downloads reliably and the whole thing works remarkably well!

Yes, I know many others have also built this successfully, but if anyone is wondering whether to give it a go, the circuit board layout works fine (I sent an updated one in a couple of months ago), the components went in without problem, the firmware downloaded easily and when it was plugged in.

It just worked!

First came across your site many months ago when I got the idea to run my under-floor heating entirely by solar power.  It's not quite as daft an idea as it sounds as I live in southern Spain, but it's still a bit of a gamble!

I have found your site very useful, and I'm impressed with the amount of information there. 

I decided I should build the arbiter and had a closer look at the drawings, especially the PCB layout.  It looks to me as though something has gone a bit awry towards the bottom of the board - various pads don't seem to line up and there's at least one missing component (C3?).

So I thought I'd have a bash at tidying up the layout a bit and, at the same time, do a revised one for the use of the MAX232 rather than the PNP transistor. 

Nice one, Nick!

Original circuit

Above is Phil's layout using my original circuit. (A high resolution image is here.)

Below is Phil's modification using the MAX232 device:

Back to the schematics page...

This page was last updated on the 2nd May 2009.