On 21 Oct 2011 at 10:33, Yigit Turgut wrote:

> Hello everyone,
>=20
> I have a sub-project where I continuously monitor LDR output  and
> drive a mini motor according to the algorithm. Motor I drive is
> manufactured by NIHON MINI MOTOR CO LTD and is perfectly driven by RB0
> and RB1 digital outputs (no other components, directly PIC-to-Motor).

Eyebrows raised as I consider the possible nasty side effects that could ar=
ise from a=20
direct motor connection to PIC, no matter how low the current... but you im=
ply this is=20
not a problem so will ignore it for now and concentrate on your question.

> My concern is  ; If I power the LDR from let's say RB4 port, how will
> this effect the stability of the system ?

By LDR do you mean Light Dependent Resistor? If yes, how do you mean affect=
=20
system stability? Are you asking about port RB4 because it may be special e=
g: open=20
drain output?

> I am not in a position to dedicate a power supply for LDR thus I am
> seeking practically effective workarounds.=20

Are you asking how to measure a Light Dependent Resistor using a single PIC=
 I/O=20
line? It would be possible to drive the port pin to charge/discharge a capa=
citor=20
through the varying resistance of the LDR and determine resistance by measu=
ring=20
charge or discharge time.

Sorry, we can't really see what you're asking just yet... need a few more c=
lues.

--=20
Brent Brown, Electronic Design Solutions
16 English Street, St Andrews,
Hamilton 3200, New Zealand
Ph: +64 7 849 0069
Fax: +64 7 849 0071
Cell: +64 27 433 4069
eMail:  brent.brown@clear.net.nz



--=20
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