BS2SX Timing Problems with the Devantech SRF04

Archiver

Doug-

Maybe just a typo, but this looks wrong:

> SRF:
> pulsout init,13
> pulsin echo,1,range
> pulsout init,13
> pulsin echo,1,range

I think you want only one pulsout-pulsin sequence per sample. The
timing specs disallow a follow-on init pulse within 10 msec of the
trailing edge of the echo pulse. That may be mucking things up.
See http://www.robot-electronics.co.uk/htm/srf04_timing.shtml

Your BS2SX also sucks up a lot more power than your BS2--about 60 mA
vs 8 mA for the BS2. Make sure your power supply can handle the
combined current requirements of your Stamp and SRF04.

Regards,

Steve

Archiver

No, it's not a typo. I have to ping twice in order to get a return.
It was like this using the BS2 and it's still needed with the BS2SX.
If I don't do it, I get a "0" for a return.

My robot is using a 9.6v/1600mA battery into a LM2940 (5v Reg)
powersupply. The SRF04 is the only load on the system right now.

--- In basicstamps@y..., "S Parkis" <parkiss@e...> wrote:
> Doug-
>
> Maybe just a typo, but this looks wrong:
>
> > SRF:
> > pulsout init,13
> > pulsin echo,1,range
> > pulsout init,13
> > pulsin echo,1,range
>
> I think you want only one pulsout-pulsin sequence per sample. The
> timing specs disallow a follow-on init pulse within 10 msec of the
> trailing edge of the echo pulse. That may be mucking things up.
> See http://www.robot-electronics.co.uk/htm/srf04_timing.shtml
>
> Your BS2SX also sucks up a lot more power than your BS2--about 60
mA
> vs 8 mA for the BS2. Make sure your power supply can handle the
> combined current requirements of your Stamp and SRF04.
>
> Regards,
>
> Steve