Homebrew PCBs

All,

This is the new thread I have started for details
on the laser plotter I am going to try build.

As stated in the just previous message - I am
aiming at something between these two articles.

http://pico-systems.com/photoplot.html

http://www.bungard.com/seiten/p-filmstar.htm

I am going to be happy with the 1000 dpi the
home built one from pico-systems does.  Finest
tracks I think I can etch are 4 thou anyways.
However 2000 dpi might be a goal to try cope
with the ludicrous pin spacing on some new
leadless metric packages.

So far I have built a text-book 4046 PLL
multiplier. This has been hooked up to a
servo motor I scavanged from something.

Unfortunatly the encoder wheel on the servo
does not have an index mark - so I will have
to scavange another one from somewhere.

The circuit for the PLL also has an Atmel on
board to regulate the speed of the servo
motor via PWM of a FET.

The main connector on the board has the 
following signals

STRT - Input  - Turn Motor On or Off
IDX  - Output - Index mark from encoder
M-OK - Output - Tell host motor at correct speed
SIG  - Output - The un-multiplied encoder signal
CLK  - Output - The Multiplied encoder signal
GND  - In/Out - Tell the host when the PCB was
                left sitting on the ground.
                (OK the last one was a joke)


NOW - to answer Lez with "I am intersted in how
you're going to get the bmp out"

There is going to be another Atmel sitting on
the end of a UART.  You will simply X-Modem a
BMP file to it and like magic it should come
out the laser.

I think this should be easy in assembly laguage
using the IN and POP instructions.

Main_Routine:
     IN     Accumulator_A, XMODEM_Data
     POP    That_Data_Out_The_Laser

As long as I can get that to assemble in AVR
studio the project should be finished tomorrow.