Hacking a Roland CAMM3 PNC-3000

[blackburn mark]

i do like the look of that machine, i can see why the wife has passed it for indoor use :)
im looking farward to seeing this one develop

[Robin Hewitt]

I replaced the EPROM so it now comes up and wants to communicate, lets me upload programs and run them.

Just did "reading the buttons". I can see the XYZ positioning encoder knobs on the front panel are going to be tricky.

To read the panel buttons and encoders I have to clock the data out serially by reading two dedicated port addresses. No problem except for the encoders which are odd. I get a direction and a brief pulse to say it's moving. Blink and you've missed it. They are not making this easy. Resisting the temptation to rewire it so I read the encoders raw :naughty:

Worry about that later, they've probably fine tuned the pulse to one step in crawl mode so I just read once per interrupt.

Next, lighting the LED's and setting the XYZ co-ordinate displays. Then I'll fire up the interrupts and get her moving again.

Still waiting for bits to do the new spindle. Bought the Ampflow E-150 DC motor and it looks delighful. Slightly concerned about how much heat it can dump into the metalwork without overheating, may need an extra fan. It's rather apart at the moment, you can see the 35mm round rails supporting the head. Feels fairly solid

[Robin Hewitt]

I got in a couple of days on the new firmware. I now have control of the knobs, buttons, motors and displays.

About 25% of that couple of days was persuading the XYZ position displays to behave themselves. Instead of TTL 7 seg display drivers they use some cack-a-mamy processor that needs to be interrupted when the direction line changes. It needs a delay after a direction change before it is prepared to start counting. No delay and it counts the wrong way. Get the delay wrong and it can go truly bananas.

No goto xyz yet, written but not tested. OTOH it does move because the Home button works. For Home I sidle up to the limit switches at 5mm/s until they are all shut. Then I back off at 2.5mm/s until they are all open. Then I wind into them again at 1mm/s. They aren't exactly brilliant, worst case repeatability is 35um out, need to think about that.

All stop now while I invent a command protocol. I want the host computer to do the sums but there is a limit on how fast i can pump information down the serial line. I need a compromise comms platform, a CCP :naughty: