New Servo Erector Set gearhead based servo!

The 22mm motors are on order. It will be several more weeks before they are here. I’m also receiving several samples of the 32mm motor, and some others… I have redesigned the main bracket and am waiting for new samples. I have the machined aluminum part that connects the motor to the pot done, but had to chage a set screw size and am waiting for new samples. I have hired two guys from the Open Servo project to make the control board, and the software. It will have all of the Open Servo features, plus servo pulse inputs. A cool trimmer pot to adjust the center position, maybe two additional trimmer pots to fine tune the PID. There will be a 5 amp and a 10 amp version. I knew the only way this was going to happen was if I hired some of it out. :smiley: So even though it looks like nothing has been done, much is being done in the background. I’m pretty excited too. :wink:

Oooohhh…

(wait for it…)

:open_mouth: Shiiiiiny. :open_mouth:

:open_mouth: i agree, you excel above and beyond wat would ever expect normal products to be Jim :smiley:

Hi Jim,

Just a suggestion (if you’re open to it) … when the Open Servo guys are building your new board, they might set up the command codes so that a board address prefix must (or optionally “must”) be added on the front of each valid command string. For example each valid command might be prefixed by a %1 (which indicates the command should be run by board 1)

This way, we could address multiple boards from a single daisy-chained RS485, or a bluetooth enabled multiple-RS232 link. For large robots, people are going to want to place multiple servo boards in strategic locations. Much better than running insanely long servo connections through twisting joint structures.

My 2 cents. Thanks for the great products

Tom

Um, pretty sure open servo is I2C based not RS232/RS485. If you want to use RS232/RS485 to talk to them you’ll need a micro in the middle to do the translation and that is where you could translate your device header info into I2C device addresses used to access the servos.

Correct. Open Servo does not currently support RS-232/RS-485. They have been tossing around ideas about RS-485, but so far nobody has run with it. There is I2C and upcoming PWM control (being worked on).

8-Dale

I think the bigger issue was that thomas wanted some way of daisy chaining the servos. OpenServo boards can do that now, you just need to set the addresses manually. By default they are 0x20 (I believe). To set the address you would connect your OpenServo an I2C channel with no other 0x20 devices. You would then first send the command to unprotect the servo’s registers, then to change the address register with the new value. You then save the change and start sending commands to the new address. The exact commands are all documented on the OpenServo site.

Absolutely. I don’t think I could have explained it any better myself. :slight_smile: Some of the documentation for the Open Servo is not very clear, but all you have to do is go over to the Open Servo Forums and ask questions, or here, since at least three of us have some pretty good knowledge of Open Servos now, and are gaining more all the time. I am not sure there is actually an unprotect command for the Open Servos, but there may well be. I have not actually looked at the command documentation yet, since I don’t have any Open Servos to tinker with. I hope to change that next month though, since I am nearly ready to start adding servos to The BiPod. :slight_smile:

8-Dale

Thanks that’s a huge help. I’ll visit the open servo forum…

T

Why not use a potentiometer instead of the more expensive encoder? Doesn’t the OpenServo project use potentiometers and not encoders?

Thanks,
Chris