Alt-BEAM Archive
Message #09648
To: beam@sgiblab.sgi.com
From: "Corey Centen" biobotics@hotmail.com
Date: Mon, 31 Jan 2000 09:15:17 EST
Subject: [alt-beam] Sensors
Hi,
I am wondering if anyone can tell me as to how I would go about adding
multiple sensors...thermistors...mics...tactile and the photodiodes to a
small bot such as the photovore??? Is it possible to add this many sensors?
How would I get a sensor to reverse a motor when it senses a stimulus?
Thanks.
______________________________________________________
9649 Mon, 31 Jan 2000 09:22:03 -0600 [alt-beam] Re: Bicore question "Phillip A. Ryals"
content-transfer-encoding: 7bit
ok, let me go one by one.
>Fast checklist:
> - are you absolutely, 100% SURE that every solder joint is good?
> Dave at Solarbotics reports that the vast majority of non-working
> robots they repair for people are due to solder joint problems.
I've gone over them three or four times. I have had problems with this in
the past, but I actually made a definite effort this time to get all good
joints the first time.
> - is anything touching that shouldn't be? Solder accidentally
> bridging a gap? Leads touching in some obscure place? I like to
> run a dental pick between adjacent wires just to be sure (with
> power off !!!)
I always run a sharp knife between all the paths, just to make sure.
> - wash/clean off the soldering flux. Some fluxes are ever so slightly
> conductive. When you are using resistor values in the Megohms, the
> flux can sometimes make a difference.
ok, I didn't do this. How exactly are you suposed to wash it off? I'm
using 2.2M resistors to get the speed down. On Andrew Miller's site, he
mentioned that you can go up to 20M for certain apps, so I didn't think it
would be a problem.
> - did you install a decoupling capacitor across your + and - supply
> near the chip? Suggested value is between 0.022 and 0.1 uf. You
> rarely see this mentioned in circuit diagrams.
nope. does this definitely make a big difference? Should I just plan on it
for every circuit I build?
> - did you "do something" with any unused chip INPUTS? Do something
> means connect them to either ground or Vcc. Unused outputs are NOT
> connected to anything.
I didn't do this either. Kinda misunderstood your question though. Should
they be connected, or shouldn't they?
> - are you using LED's to check your microcore behaviour? Are they
> installed right way around?
yup, to both questions. :)
content-transfer-encoding: quoted-printable
>
ths, =
just to make sure.
> - wash/clean off the soldering =
flux. =
Some fluxes are ever so slightly
> conductive. When=
you =
are using resistor values in the Megohms, the
> flu=
x can =
sometimes make a difference.
ok, I didn't do this.=
=
How exactly are you suposed to wash it off? I'm using 2.2M resistors =
to =
get the speed down. On Andrew Miller's site, he mentioned that you ca=
n go =
up to 20M for certain apps, so I didn't think it would be a =
problem.
> - did you install a decoupling capacitor =
across your + and - supply
> near the chip? Suggest=
ed =
value is between 0.022 and 0.1 uf. You
> rarely see=
this =
mentioned in circuit diagrams.
nope. does th=
is =
definitely make a big difference? Should I just plan on it for every =
circuit I build?
> - did you "do something" with any=
=
unused chip INPUTS? Do something
> means connect th=
em to =
either ground or Vcc. Unused outputs are NOT
> conn=
ected =
to anything.
I didn't do this either. Kinda =
misunderstood your question though. Should they be connected, or shou=
ldn't =
they?
> - are you using LED's to check your microcor=
e =
behaviour? Are they
> installed right way =
around?
yup, to both questions. =
:)
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