Details of an autopilot controller I've built for our yacht:
http://www.alphalink.com.au/%7Ederek.../autopilot.htm

It's a bit "techie" for most people, but some may be useful to some.

On Mon, 27 Jun 2005 13:31:45 +1000, Derek Weston
wrote:

Details of an autopilot controller I've built for our yacht:
http://www.alphalink.com.au/%7Ederek.../autopilot.htm

It's a bit "techie" for most people, but some may be useful to some.


Nice work, Derek!

It's sad to see that RadioShack is compacting their stocks of ICs -
nobody does it much, any more.
A mix of easy cheap products, and shruken surface mounts, and above
all - lack of insight bred in the bone - from fooling with clocks and
toys and old radios and things of that kind...did for the hobbyist
market, I think.

But parts can still be ordered.

Brian Whatcott Altus OK

Brian Whatcott wrote in
:

It's sad to see that RadioShack is compacting their stocks of ICs -
nobody does it much, any more.


http://www.mouser.com/

They will sell you ONE resistor, if you're willing to pay the freight
charges on it. MC/VISA/AMEX/Discover....gladly accepted.

If you request a catalog online, they'll send you this huge parts catalog
about every 3 months. If you keep ordering small quantities of parts,
they'll keep sending you the catalog forever!

They have all the parts....and quite cheap considering you're not buying
thousands at a time.... I use them all the time. So don't most of my ham
friends who still like to build...

--
Larry

You know you've had a rough night when you wake up and you're outlined in
chalk.

Derek Weston wrote:
Details of an autopilot controller I've built for our yacht:
http://www.alphalink.com.au/%7Ederek.../autopilot.htm

It's a bit "techie" for most people, but some may be useful to some.

Not being a techie (but having a good friend who could
probably build this in his sleep) - about how much would the
parts cost to build this?

Evan Gatehouse

Looks like the basic electronics would be under $100 from Digikey but that
does not include the printed circuit, enclosure/switches, motor and drive
train. Source code seems to be well laid out and commented and the circuit
is pretty straight forward. Laying out and etching a PCB would be fairly
simple and anyone with a programmer and a PIC compliler can set the chip up
for you in a few minutes.

The main problem I see is that it can't drive motors with less than 2 ohms
resistance or about 6-8 amps at 12V. That is under 1/10th HP so the drive
will have to be very slow or low torque. Probably OK for up to about 30'
but not much larger. Also by using back EMF to track rudder position limits
the drive train to purely mechanical linkage. I think hydraulics would be
out.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Evan Gatehouse" wrote in message
...
Derek Weston wrote:
Details of an autopilot controller I've built for our yacht:
http://www.alphalink.com.au/%7Ederek.../autopilot.htm

It's a bit "techie" for most people, but some may be useful to some.

Not being a techie (but having a good friend who could probably build this
in his sleep) - about how much would the parts cost to build this?

Evan Gatehouse

Glenn Ashmore wrote:

snip
Also by using back EMF to track rudder position limits
the drive train to purely mechanical linkage. I think hydraulics would be
out.

It may work OK with hydraulic drive steering. I've not tried it.

Using back EMF to track rudder position is imprecise for several
reasons, and the errors may accumulate. To accommodate this, there is a
routine in the code which compensates for slow divergence of deduced
position from actual position. It does this by slowly shifting the
deduced helm neutral position towards the running average deduced
position. I think this would also allow slow "slippage" in the hydraulics.