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Discussion Starter #1
Hi, I just finished building a life sized animatronic figure that
incorporates 23 analog servo motors, and i'm just starting to program
it, but I have a problem. The Problem i'm having is communication
errors between the computer and the usb parallax propeller servo
controllers (2 of them). What happens is that if I have the baud rate
set to 38400bps and i tell the servos to move to their default
positions or even if I tell the program to start; the servos will just
move to a random position. But if I set the Virtual COM baud rate to
2400bps everything works just fine. But, I need the baud rate to be
set to 38400bps, which is supported by these servo controllers. Also
I'm running on Windows 98SE (don't judge) and all the necessary
drivers are installed. The programming software i'm using is called
"Visual Show Automation 3.1". Any help would be much appreciated.
 

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I'm not real sure but I think you need a real com port to run that board. I used 2 of the Parallax servo controllers when I ran 3 3 axis skulls, each one had 6 servos in it. I also ran some other things from those boards but for the skulls I had 2 on 1 board and the 3rd one on the other board. I had to use 2 com ports on that set up but if you used a Stamp microcontroller you can daisy chain them together as shown in the instruction manual. I also was using the 3.1 VSA. Hope this helps.
 

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Yes, each servo controller would only support 16 servos and I had 18 servos between 3 3 axis skulls and was running some lighting and other things so I needed a total of 28 or 30 outputs.
The ports were usb com ports, I don't think they were "virtual" I think they were real ports. I'm not real savvy on computer stuff like that. Yes ,I needed 2 usb ports.
I set the baud rate in VSA
There were some error messages and I can't remember what they were. I do remember that they were a hiccup in theVSA software and just required a reboot of the software.
 

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Discussion Starter #5
PROBLEM SOLVED

What I discovered is that the Default Baud rate 2400bps was hard coded into the source code of the Parallax Propeller servo controller's firmware. That's the reason it would only work on 2400bps. So all I did was change the Baud rate in the source code from 2400bps to 38400bps, then I recompiled the modified firmware and loaded it back into the Propeller chip on the servo controller. I hope this helps anyone else that might encounter this problem in the future.
 

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Glad you got it working! My robot skeleton uses serial communications as well, but it only runs at 2400bps, so I don't have any choice. I wish it DID run faster... but what can you do? I'm using an out-of-production chip (anyone ever hear of Ferretronics?) so I don't have a lot of options unless I completely redo everything from scratch. New controllers, new software, etc. etc. :(
 
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