Continuous Rotation Servo's

Scop

Hello all, I have a few questions regarding the continuous rotation servo's that parallax sells. First off I am using them in a robotics application, and it seems that I cant find all the information I want from the spec sheet provided. I was wondering what the max load/suggested voltage on the I/O wire would be. The servo's Vdd itself would be 6V, but I wasn't sure about the I/o (white wire labeled on the specs) since it is connected via 5V signal from the micro controller.

I'm also a little curious about the servo's feedback. I am planning on using an opto-isolator so nothing can damage my micro controller, but I was just wondering if anyone else had some problems with this, or if i don't even have to worry about it. I'll probably use it anyway even if i don't have anything to worry about, better safe than sorry. (And frankly its a cool part )

A link to the servo spec's can be found here -->here.

Post Edited (Scop) : 10/7/2008 3:20:53 PM GMT

SRLM

Why are you trying to put more than 5v on the I/O line? You could probably get by with the Max V, but I don't know. As for the feedback, I've never had a problem. Since the pin (for me, the BS2s) is output, no signal ever makes it in. As for power feedback, I've never noticed a problem. I suppose if you're running 16 of the servos, you might need to get an external power source, but for two or three I've had fine results.

allanlane5

The I/O line is a TTL digital signal line, which takes very little current (< 1 mA, maybe much less than 1 mA). Since it's "TTL", it needs a 5 volt line, voltages much over 5 volts will destroy it.

Now, the signal line is used to control a MUCH larger voltage and current flow from Vdd to Vss. The Vsupply on a Servo can be 5 to 7.5 volts.

Scop

Thank you so much, thats the information I was looking for. Breaking these servos is defiantly not on my design plan.

Post Edited (Scop) : 10/11/2008 5:13:06 PM GMT