AVR-Chat

I agree with the CLEAN 5V but you do not need 2 sources. You can use the
same source for motor and MCU. You need to put a separate voltage
regulator on the MCU circuit from the motor circuit with caps going from
the input to ground and from the output to ground. 

Also an important consideration is the type of voltage regulator you are
using. If it is a 7805 you need something like 1.5 volts above the
output which over 6.5 volts. This means you can not use 4 AA batteries.
Six AA 1.5 V batteries will give you plenty of room but 6 AA
rechargeables only have 1.2V which is still borderline.


-----Original Message-----
From: Dave VanHorn [mailto:dvanhorn@dvanhorn.org] 
Sent: Thursday, November 25, 2004 1:15 AM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] controlling relays and motors




>
>The biggest question is: is the problem caused by HARDWARE
>or SOFTWARE? i look at my software and it seems ok. i look
>at the hardware schematics and it also looks OK. In the situation like 
>what i am in now, which should i check first? Hardware? or Software?
>
>If i must check hardware, why does the error only happens occasionally 
>(getting more often lately) and not ALWAYS?

The simple answer, is that you don't always produce the same noise.

>Sorry if i dont give you much information about my
>project. I am really upset now :(


Ok.. First, power the micro from a CLEAN 5V supply, that does not come
from 
the same source as the motor power. The only thing they should share, is
a 
single point of connection on the ground, so that the signals have a
common 
reference.

Second, how are you switching your inductive loads?

Are the relays connected with snubbing diodes?





 
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