Propeller Servo Controller USB 28830

youngti

All.

I have been using the old non propeller servo controller for many years. I have them hooked to skeletons and controlling them from my computer using VSA. However they are not working now so a while back I purchase some of the 28830's. I have tried to replace the old ones with the new style but nothing seems to work. I had thought I could just swap these new one in and be good to go.
When I do this the board is seen by the computer, I can configure VSA for the correct com port but the servos attached do nothing. I have a separate power supply to the servos and it is connect to the usb on the computer.

Is there something I need to do with the new ones to get them to work as computer controlled usb devices like the old one?

VonSzarvas

In case you don't have them, here's the user guide and firmware files :

https://www.parallax.com/search?search_api_views_fulltext=28830

If your still stuck on Monday, try calling or email Parallax support directly. Sorry I can't offer any other advice - don't think I've ever seen the 28830! Parallax Chris in support may well have experience with these, if no other forum users can help.

MikeDYur

@youngti, Don't forget that the Propeller Servo Controller requires TTL level serial interface to the microcontroller. CMOS level won't move the servos.

Publison

Can you tell us what controllers you were using in the past? That could help. What version VSA?

Also what servo are you using, (analog or digital). we had a couple of threads a few years ago, indicating that you may need a ~5K resistor in line with the servo signal because of the translators on the Servo Controller.

JonnyMac

Some years back there was a guy using VSA who had problems with VSA sending more data than the PSC could handle because -- at the time, anyway -- it was using the original version of FullDuplexSerial that had a 16-byte buffer. I updated the buffer size to 64 and the VSA project worked fine after that. Check the firmware.

youngti

They were the original parallax USB servo controllers around 2005. VSA version is 4.0

Publison wrote: »

Can you tell us what controllers you were using in the past? That could help. What version VSA?

Also what servo are you using, (analog or digital). we had a couple of threads a few years ago, indicating that you may need a ~5K resistor in line with the servo signal because of the translators on the Servo Controller.

Shawn Lowe

Does Parallax even make these anymore? I can't find any information on the actual board, not the docs.

VonSzarvas

Shawn Lowe wrote: »

Does Parallax even make these anymore? I can't find any information on the actual board, not the docs.

Discontinued long ago, although you should find docs and firmware using the link in post #2 above.

Publison

youngti wrote: »

They were the original parallax USB servo controllers around 2005. VSA version is 4.0

Publison wrote: »

Can you tell us what controllers you were using in the past? That could help. What version VSA?

Also what servo are you using, (analog or digital). we had a couple of threads a few years ago, indicating that you may need a ~5K resistor in line with the servo signal because of the translators on the Servo Controller.

Have you tried the PSCI software to verify if the original board is working? I have attached the software.

EDIT: The software is too large to upload. Will look for a link.

Publison

I sent the file to your email address.

Bill Henning

FYI, if you don't mind kits, RoboPi can control up to 24 servos, and has an MCP3208 eight channel 12 bit ADC.

http://www.mikronauts.com/raspberry-pi/robopi/



It does not have USB, but does have 3.3v PropPlug compatible header.

It also stacks on >12 models of SBC's (incl Raspberry Pi)

If you used a 5MHz crystal instead of the 6.25MHz crystal RoboPi supplies, it should be able to run the Prop servo controller firmware.