Over in the discussion sidebar, Wayne Garris and James Hall have been working through the details
of how to build a BASIC Stamp autopilot, which we use in in GeoCrawler3
(formerly 4--sorry for the confusion!). They're doing a great job of catching bugs and otherwise sharing tips, but this has been a reminder to me that I should post a tutorial on setting up the hardware. So this will be the first of several posts on assembling the board and components for this autopilot, and customizing the software for your own needs.
First, let's just set up the board to control a single servo with the FT639 chip
on the Parallax development board
(later on I'll show you how to do it using the Parallax servo controller board
, if you prefer that). The single FT639 chip has the advantage of being small and easy to integrate into a single-board autopilot, but it's not the greatest servo controller in the world and doesn't handle high-speed applications well (we're just using it on the rudder, so it's fine for our purposes).
In this case I've connected the FT639's serial-in pin to the Stamp's pin 8 (yellow wire), and the FT639's servo 1 output pin to the signal pin to servo connector p15 (blue wire). The black and red are ground and power, of course. Couldn't be easier.
Here's the code
that just tests this servo in several position. Once you get this working, the next step will be to read the R/C receiver input signals and pass them through to this servo. Go to this next post here