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Topic: xBee: duplicate response (Read 2 times) previous topic - next topic

maraesa1000

I read somewhere that things connected to the relay had to share a common ground with the arduino (and its been in the online tutorials/projects that ive been referring to). I just thought 'hang on a second....what if...' and I put the yellow wire on the opposite side of the relay (parallel to the orange wire) and now it works perfectly. As far as i can tell its not connected to ground. This projects slowly driving me crazy! Siobhan

Jack Christensen

#11
Apr 26, 2012, 06:43 pm Last Edit: Apr 26, 2012, 06:44 pm by Jack Christensen Reason: 1
Now if I were Grumpy Mike, I'd refuse to try and interpret that schematic. Actually I gave it about three minutes and that's all I'm willing to do. Seriously, a proper schematic even sketched with pencil on paper and scanned in would be far better. The way that 1N4001 appears to be connected just makes no sense at all. Sorry about that, don't take it too personally! But try to find a better way.

Having said that, here are a couple things that strike me off the top. Driving the relay direct from an Arduino pin is probably not appropriate. Do you have specs on the relay? What are its rated coil voltage and current? The problem is that most relays need more drive than an Arduino can provide, so using a transistor at least to provide more current is usually needed. So a resistor is actually sort of the opposite of what is needed. Ditto with an MP3 player. And using a speaker in place of an MP3 player is way off in left field. If that's a dynamic speaker, it probably represents nearly a dead short to the pin. I hope your Arduino is OK.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

maraesa1000

Lol thanks for trying. It really is a mess! Luckily my problem is already solved. I think it was a case of not knowing how to use the relay. My relay is being powered by the arduino on 3.3v (as this is the voltage that my xBees work at). It came with a beginner kit from oomlaut.com and this is what the accompanying tutorial instructed. There was no schematic or power information provided so i was kind of guessing.

This is the basic circuit i was working with http://www.oomlout.com/oom.php/products/ardx/circ-11 i am using the same relay and transistor.

I've had to adapt it to work with my mp3 player. The way i've wired it up now makes no sense according to the diagram but it works reliably so i'm quite happy with it.

Cheers!

Jack Christensen

From the oomlaut page, I'd assume that it's a 5V relay. It may operate on 3.3V. Then again it may not, or it may sometimes, or mostly.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

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