Propeller controlled servos

BipedPete

How many servos can be controlled by a Propeller?

I have some biped robot experience and I want to try one with the propeller. The one I am working on currently has 12 servos. It is basically two legs. Can a Propeller handle that? If so, should I get the Proto board or the stand alone chip?

Post Edited (BipedPete) : 7/23/2007 7:56:23 PM GMT

CJ

for lots of servos I like the Propeller Robot Controller

www.wulfden.org/PRC/index.shtml

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Parallax Forums - If you're ready to learn, we're ready to help.

Mike Green

The Propeller chip itself can handle up to 32 servos. Practically, it can handle 28 since the EEPROM is on pins 28 and 29 and the PC serial link is on pins 30 and 31. These pins can be reused once a program is loaded and running, but servos on those pins would need additional circuitry to disable them while the initialization process is taking place.

simonl

I'm sure I've seen an OBJect that claims to be able to run 96 servos, but it would need additional circuitry (multiplexers?) to achieve this.

Has anyone actually tried it?

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Cheers,

Simon

---

www.norfolkhelicopterclub.co.uk
You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-)
BTW: I type as I'm thinking, so please don't take any offense at my writing style

BipedPete

Thanks for these answers. I will order the Propeller soon.

BipedPete

Thanks also for the Link CJ.

Beau Schwabe

BipedPete,

Here is the thread mentioned....
http://forums.parallax.com/showthread.php?p=576634

When I wrote the code for the 96 Servo driver, the progression was originally from the 32 Servo driver.
...Which led to a hardware version to control 48 Servo's. The 48 version was actually a baseline limit due to timing
restrictions of a standard servo. The 96 Servo version and then 144 Servo version are double and triple duty versions
of the 48 Servo driver.

simonl,

When I tested the Servo Controllers, I tested them in "Hardware" groups of 8 with the software running as though all servos were connected.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

Post Edited (Beau Schwabe (Parallax)) : 7/24/2007 9:23:46 PM GMT