“There’s nothing quite like a nice, simple hack. This serial servo controller uses a PIC12C671 and a pair of resistors. Leaving out the power supply, that’s the lowest part count I’ve ever seen.”

..”_this_ servo controller”.. The “_this_” syndrome is almost as bad as the click _here_ syndrome.. Perhaps “This _servo_ _controller_ ..” would be better.. I think I’m just taking the piss though, and also I’ve had too many beers.. I’ll shut up now.

Posted at 1:15 am on Apr 26th, 2008 by Bullwinkle Jones

why need the resistor from the pic to servo, look at http://www.epanorama.net/documents/motor/rcservos.html it seems servos take an 5v input control wire.

Posted at 2:19 am on Apr 26th, 2008 by spaceballs

Does anyone know how to simply control a small 3-5v DC motor through USB? I would like to see that.

Posted at 4:44 am on Apr 26th, 2008 by Crash

crash, just use some atmega8, a transistor as motor driver and some usb->rs232 chip.

Posted at 5:52 am on Apr 26th, 2008 by julian

I agree, the resistor between the PIC and the Servo is not required. Most Micro Controller manuals are geared toward the beginner, and have the resistor to protect the Micro against a miswire (accidentally hardwired to a power supply rail.)

It should be trivial to write a timed routine in any modern language (C#, Java…) to toggle a pin on the Serial or Parallel port every 20mS. It may have some jitter, but it also has a zero parts count!

Posted at 9:32 am on Apr 26th, 2008 by Almost There

I’ve built many serial servo controllers and you don’t need those resistors. All that is required is a PWM output to the control line of the servo. Thats a part count of two: servo and mcu.

Posted at 9:41 am on Apr 26th, 2008 by brandon

12C?

What does the C stand for? I know the F family of microcontrollers is named after the internal flash but I’ve never heard of C family.

Posted at 1:30 pm on Apr 26th, 2008 by Hackius

hackius: the c means that the micro can only be programmed once. since f and c types are interchangeable, the c types aren’t used much anymore except in mass production.

Posted at 3:10 pm on Apr 26th, 2008 by andrew

Here’s a couple of my own simple PIC 12F675 servo controllers.
http://www.ringolake.com/pic_proj/servo/servo_weasel/servo_weasel.html

Posted at 3:24 pm on Apr 26th, 2008 by N0QBH

It is nice having such a low parts count, it really makes stuff compact and easy to build. But you just can’t beat the dedicated servo controller chip…especially if you don’t know how to program pics like me. I know all the syntax for java and perl and stuff, I just don’t have the creativity to make good programs, so having a dedicated part to do a job is still a high priority in my book.

Posted at 6:59 pm on Apr 26th, 2008 by mike

Hackius, the “c” is the non-flash version. You can only burn the code into the chip once, they are just a bit cheaper than the flash rewritable ones.

Posted at 8:04 pm on Apr 26th, 2008 by kwa

I must apologize for last nights obviously drunken writings.. Bad Matthew!

Posted at 1:39 am on Apr 27th, 2008 by Bullwinkle Jones