burning question - HSI?

[ruprecht]

We can get the LEDs from mouser for $2

This really gives me the irrits - same product, same manufacturer, 10 times the cost in Aust. That's economies of scale for you.

[AndyT]

http://www.portescap.com/Repository/...r_01042007.pdf

And what it looks like...

[AndyT]

When we are done, we can figure something out on parts and shipping and such...

[ruprecht]

mhmm... US$19 for a 20 steps/rev motor... this one is about the same price and 48 steps/rev?

[AndyT]

This one is $17 US and 48 steps.
http://www.portescap.com/Repository/...r_01032007.pdf

Take your pick.

[ruprecht]

That's the one. Awesome. They don't ship outside the US, so we might need you to buy 12 and on-ship 4 each to me and scott!

For the electronically minded, here's a challenge: design a microcontroller circuit within the following constraints:

- fits on a circular circuit board < 60mm dia.
- has only 5 inputs: data ground, data +, data -, power ground, power (5 or 12V)
- ideally uses a PIC flash microcontroller (e.g. PIC16F648A)
- can control a micro servo through roughly 90 deg movement, plus three separately controlled LEDs
- MAY be a daughterboard with a larger separate motherboard, but must conform to the input limitation above
- is suitable for home fabrication (so keep the traces at a reasonable width) or consumer board shop (e.g. PCB123, ExpressPCB)
- please supply Eagle or PCB123/ExpressPCB layouts

*EDIT*
- Contains some sort of protection to ensure the servo does not move unpredictably at startup. Possibly prevent power being supplied to the servo until a stabilising pulse train is active?
- Has approx 10mm dia hole in the centre of the board for a shaft to pass through.
- has holes for 3 #4-40 mounting screws
- supports ICSP so we don't have to disassemble the whole instrument or pull the chip to update firmware

Who's up for the challenge?

[AndyT]

Lets limit it to Express PCB since I have that one also.

[AndyT]

Hmmm..... Check this out....
http://www.futurlec.com/Mini_SMCC.shtml

[ruprecht]

One for the stepper gurus: will the L293D bipolar H-bridge driver (600mA) be able to drive this stepper? (note the 12V bipolar version).

[Westozy]

Hi guys,
Re - tubes, bushes, rollers, axles etc, I can make what you need to any size and post them over. This is a great project growing on our pages and it would be good to see a working prototype!
(Tip - break apart old printers, they are a great source of small mechanical parts).

Gwyn