Olin,

> Comments?

Looks like a good idea to me!  :-)

As others, I am a tad confused at the complexity of the power supply - I like the basic concept of having the 
regulation on-board, and the "idiot-proofing" of using a bridge rectifier, but I'm finding it hard to think of 
a reason for a 5V5 supply!  Perhaps I've missed something?

On Wed, 18 May 2005 17:50:58 -0400, Olin Lathrop wrote:

> Page 5: Prototype area.  There will be uncommitted strips of 5 pads
> surrounded by bus lines, much like the common "protoboards".  The schematic
> is roughly laid out like the real board will be, except that there won't be
> a space every 10 pins.  That's just for my sanity in working with the
> schematic.  The pad strips and busses will be connected on the bottom layer,
> with the top being a ground plane flowing around the holes.  The top silk
> screen will also indicate how the holes are connected.

Excellent idea!  I've never understood why prototype areas on (say) Microchip's PICDem boards have just an 
individual anulus of copper around each hole - why not have strips?  I said as much to the Microchip reps at 
the recent seminar here - they didn't know either but thought it may be to do with the way people in the USA 
do prototype wiring!

The idea of having the prototype area at the front with the pre-installed parts behind sounds good, however 
I'm not clear what the physical layout of your pad-strips would be.  

My suggestion would be a pair of horizontal bus strips (not connected to power - leave that to the user) with 
vertical strips either side, making it easy to install DIL chips and connect them to power, easy to put 
decoupling caps close to their ends, and other components around them.  However, I've seen boards where the 
strips are not continuous full-length, giving "interwoven" strips which can be handy - basically you have 
breaks in the strips every now and then, which do not line up across the strips, for example: ( O=O  are 
connected holes,  O*O  is a break in the strip):

O=O=O=O=O=O=O*O=O=O=O=O*O=O=O=0=0=0
O=O=O=O=O*O=O=O=O=O=O=O=O=O*O=O=O=O
O=O=O=O=O=O=O*O=O=O=O=O*O=O=O=O=O=O
O=O=O=O=O*O=O=O=O=O=O=O=O=O*O=O=O=O
O=O=O=O=O=O=O*O=O=O=O=O*O=O=O=O=O=O

I presume you'll have pads at the back of the prototype area connected to the PIC I/O pins, to make patching 
to them neat and easy?

I feel it would be useful to have some patterns that are not 0.1" grid - putting a surface mount device could 
be allowed-for by having a small area with pads for the most common SMT spacings (0.050" ?), fanned-out to 
small strips on 0.1" grid, rather like the central part of the "Surfboard" products such as this: 
http://www.capitaladvanced.com/9081.htm

The other thing that I always have trouble with on 0.1" boards is things like D-type and RJ45 sockets, which 
have the pins o 0.1" grid but with one row 50% staggered in relation to the other.  So a strip of staggered 
holes along one edge (also fanned out to "straight" 0.1" strips) would be really handy!

And finally while I'm here:  how do you get Eagle to create strips of connected holes with no components in 
them?

Cheers,


Howard Winter
St.Albans, England


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