Re: [Autopilot] Sketchy problems with Rev2 board

[Cory D. <cor...@co...>]

From: Tramm Hudson <hu...@sw...>
> Cory Dixon wrote:
> > So,I have a Rev 2.4 board populated with the Atmel, max232 and the 4017
servo
> > drivers and I am using directly from CVS.
>
> Glad to hear that it went together, although I bet that you have the
> 2.2 or 2.3 board design.  We're at 2.4 on the software releases, but
> CVS is the best way to go.

Excuse me, you are correct.  We are actually on the 2.3 board, and just
using CVS.

> > First off, in servo.h there is the line
> >
> > if( servo == SERVO_MAX - 2 )
> >
> That's good.  I think Bram had fixed that as well, but I still see jitter
> on my servo 0 for some reason.  I haven't figured it out, but haven't
> had enough time to hack on it.

Have you noticed on the Rev2.3 boards, that T1 from the Atmel touches ground
about half-way between the Atmel and the 4017-A chip. Look for the via that
connects ground to the 4017-B chip.  The via interferes with the T1 line.
We have already scratched out the connection on our board.

> If you load a test code that just prints "Hello, world" and maybe drives
> the servos, does it fail as well?  Or is it only if you have the full
> code from CVS that causes the problems?

I have test code that just runs the servos, and outputs to the serial port.
I developed this code from code directly out of the rev2 directory from CVS.
I first noticed the problem running this code. I have actually ran the rev2
code on the board, and watched it run for a little bit.  But, once I noticed
this problem, the rev2 code just stops running after a few lines of output.

> It might be a power related issue.  What sort of power supply are you
> using?  I have seen nearly dead batteries provide power for a few seconds,
> but then cause the Mega163 to go into brown out reset.

I was just using a 9V battery for a while, but also suspected it.  So, now I
am powering through a 12-V DC Wall convertor.

> You'll be ok without the boot loader, although I actually find it
> easier to use than the ISP these days.  My ISP cable is only 1.5 m long,
> but the helicopter is a long way from the computer.

Good point.

Thanks for all your help, and your quick reply's.
Cory