Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: Ryltar on June 19, 2009, 01:25:12 AM

Title: Sharp IR and Axon: Reset repair query
Post by: Ryltar on June 19, 2009, 01:25:12 AM

I recently purchased several Sharp IR GP2D12 sensors to use with my Axon. It kept having issues when I tried connecting the Sharp sensors. I looked around and read the posts about it. Made sure the battery is charge (6v 2300mAh) and the code is okay. It all seems to be. I then tested everything without any Sharps connected, and it worked (though a little badly, my IR 'bumpers' have a few blind spots). I then attached one Sharp and the it stopped functioning. Not even the LED I coded to turn on when it is ready to run lights up. This happens with any of my three Sharps, doesn't matter which.

Since those checks didn't resolve the problem, I figured I would go on to the next step; adding in the caps and resistors recommended here (http://www.societyofrobots.com/axon/axon_FAQ.shtml#sharp_ir_reset).

From what I read, the 10uF cap connects the Red (VCC) and Black (Ground) wires and the 10nF cap and the 530 ohm resistor are connected in parallel and connect the Black and Yellow (Vout) wires.

My question is this: Am I correct with my understanding of the cap and resistor additions? I have a very limited cashflow right now and really don't want to fry something.

Here is a fuzzy pic of my robot (http://twitpic.com/7s16p) just for reference, and because I want to show it off a little. He is still in the very starter stage.

Title: Re: Sharp IR and Axon: Reset repair query
Post by: Admin on June 19, 2009, 04:23:32 PM

Quote

From what I read, the 10uF cap connects the Red (VCC) and Black (Ground) wires and the 10nF cap and the 530 ohm resistor are connected in parallel and connect the Black and Yellow (Vout) wires.

My question is this: Am I correct with my understanding of the cap and resistor additions?

Yeap that will work fine. Putting caps between power and ground will never fry anything - only reduce power supply noise (a good thing).

Another advantage to this hack is that it will greatly improve the Sharp IR sensor stability (which is otherwise inherently noisy).

Title: Re: Sharp IR and Axon: Reset repair query
Post by: Ryltar on June 20, 2009, 07:09:49 AM

Thanks, that is what my understanding was. I just wanted to make sure :)