> Page 1: Power supplies.  The board will run from many cheap AC wall warts.
> There will be a 1.3mm socket for the same wall wart I use for the EasyProg
> and ProProg, plus screw posts for both AC and DC bare wire inputs.  The
> final rectified voltage needs to be about 11-30 volts.  DC supplies from 12
> to 30V will work fine.  A basic buck regulator makes 5.5V, which is linearly
> regulated to 5.0V with an LDO.  I've done this in another design and it
> worked very well.

As others have mentioned, allowing for adjustable Vdd and a 9V battery
might be nice.  Also, and this may be a minor point or something for the
user to worry about, but it'd be cool to see some feature which makes
monitoring the current consumption easy- maybe a jumper that can be
removed to provide a shunt?  Although I can see that degenerating into
"Why the bloody #$%^ won't my circuit run?  It only runs when I'm
watching the current consumption!"

I like the thought of being able to "jumper out" the on-board regulation.
Things like that make it easier to use this to prototype low-power
circuits.

> Page 2: This is the PIC with its immediately surrounding circuitry.  There
> are pads for two types of crystals, one thru hole and one surface mount.  Of
> course at most one is intended to be used at a time.  Pushbuttons to ground
> are connected to the port B interrupt on change pins with internal pullups.

Perhaps being certain to include pads for a 32.768 kHz crystal near the PIC,
for easy and accurate Timer1 RTCs?  This could probably be covered by the
planned holes, if a ground hole is provided near by.

> Page 3: RS-232 interface.  The three jumpers make this optional.
> 
> Page 4: Diagnostic LEDs.  These are uncommitted so that you can wire them to
> any signal you wish.  Each signal has two LEDs, one lit when the signal is
> high, the other when low.  This is useful for seeing short pulses when a
> single LED would othewise be in the on state.  It also avoids having to
> configure LED polarity.
> 
> 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.

A small surface mount prototyping area?  Laid out properly, it'd be fairly easy
to allow the user to put down, say, three 8-pin SOICs, or two 14-pin, or one
28-pin, and provide a couple of holes to tie those components to others in
the prototyping area.

I also want to ask:  what happens as the pads in the prototyping area start
to "wear out" (i.e., my ham-fisted soldering skills cause them to lift, etc.)?
Other than using a solderless breadboard (ick), is there a fix for that?
Perhaps some clever method to make that part of the board replacable?

> Instead of having two or three boards trying to cover lots of ground, I'd
> rather create more targeted boards that are good fits for what they are
> trying to to.  I thought the generic PIC in a 28 pin DIP package would be
> the first target.  40 pins, dsPICs, CAN, USB, Ethernet, etc, etc, will all
> be different boards.  I'm hoping to have the first one available by Masters.

If you get it done soon enough, I'll order a few with the EasyProg I'm
putting off ordering.  ;-)

Mike H.

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