USB2dynamixel communication problems

[hazard]

Hello,

I'm having problems with sending commands in my computer do dynamixel servos.
I have Windows 7, 32bits in my laptop, I use the USB2dynamixel to interface with AX-12+ and MX-28 servos.

I tried the example in 1.02 SDK "Read_Write", but I always get some kind of communication error:

Code: Select all

 Succeed to open USB2Dynamixel!
Press any key to continue!(press ESC to quit)
0   0
Success: 0   0
0   0
Success: 0   0
0   0
Success: 0   0
0   64001
COMM_RXTIMEOUT: There is no status packet!
Press any key to continue!(press ESC to quit)
0   64000
COMM_RXCORRUPT: Incorrect status packet!
Press any key to continue!(press ESC to quit)
0   64000
COMM_TXFAIL: Failed transmit instruction packet!
Press any key to continue!(press ESC to quit)
0   64000
COMM_TXFAIL: Failed transmit instruction packet!
Press any key to continue!(press ESC to quit)
0   64000
COMM_TXFAIL: Failed transmit instruction packet!
Press any key to continue!(press ESC to quit)


Dynamixel wizard also crashes most of the time.


I tried to run the same example in my friend's computer, also Windows 7, 32bit, the same setup, and it works fine.


So I assume something is wrong with my computer.

I tried 1.01 and 1.02 SDKs and tried several driver versions for the FTDI. There are no changes, I still obtain the same errors.

Does anyone have any suggestion?

[i-Bot]

Dynamixel wizard is reliable, so if it works on another PC, then the FTDI drivers are first to check. You may need to check in the registry what drivers are present for the device. Then do some cleaning up.

[hazard]

Dynamixel wizard is reliable, so if it works on another PC, then the FTDI drivers are first to check. You may need to check in the registry what drivers are present for the device. Then do some cleaning up.

Yes, that was my first guess after checking in another computer.
Because I always used FTDI devices without problems. Even yesterday Makerbot worked fine.
Over the years, several versions of drivers have been through my computer, so I tried:
- Using the clean-up utility provided by FTDI
- Installing 3 versions of ftdi drivers, the version that cames with dxl sdk 1.01, the current drivers, and the beta drivers.
And obtain the same results.

Now I am trying to figure out if is there any conflicts in my PC.

[sharpyuk]

Probably a silly question, but what are you using to power the servos?

They need an external power source as the USB port is unable to provide enough power..

Cheers

[hazard]

Probably a silly question, but what are you using to power the servos?

They need an external power source as the USB port is unable to provide enough power..

Cheers

There's no silly questions in troubleshooting.

I power the servos through a bench psu at ~9V.

I am able to access, read and change the configuration in Dynamixel Wizard. I am able to run the SyncWrite example in the SDK. But most of the times the status packet is analyzed, it returns an error.

[hazard]

Ok, I've found the problem.

My laptop's adaptor is not grounded, and my friend's is.

This causes the communications problems.

Problem solved, I have to disconect the laptop adaptor when using a bench psu to power the servos. Or use a battery to power the servos when using the laptop's adaptor.

There you go sharpyuk, there are no silly questions.