RoboSavvy Forum

USB2Dynamixel with no CM5 not working

2010-10-28T22:33:32+01:00

Thanks for the input, but the servos responded when connected to the CM5.

In the meantime I got a new USB2Dynamixel and everything is working fine. So I probably short-circuited the Data and (+) pins of the USB2D

Statistics: Posted by clusher — Thu Oct 28, 2010 10:33 pm

USB2Dynamixel with no CM5 not working

2010-10-28T19:19:18+01:00

This may or may not help,

I had a bunch of AX-12s suddenly stop working. When I checked them with the dynamixel manager I found that they were set to not report. Once I toggled that switch all but two worked again.

DB

Statistics: Posted by Darkback2 — Thu Oct 28, 2010 7:19 pm

USB2Dynamixel with no CM5 not working

2010-10-19T16:09:37+01:00

Yep, when I shorted the DATA and GND intermittently the RxD led flashed.
I'm in Portugal, at IST. I'm actually in the same university as Limor.

Statistics: Posted by clusher — Tue Oct 19, 2010 4:09 pm

USB2Dynamixel with no CM5 not working

2010-10-19T15:52:12+01:00

When in dynamixel manager and TTL mode , if you intermittently short the data line to ground ( Wire two outer pins of the 3 pin connector together and pulse the connection, then the RxD LED should flash if the TTL receiver is working on the USB2Dynamixel.
Where are you located ?

Statistics: Posted by i-Bot — Tue Oct 19, 2010 3:52 pm

USB2Dynamixel with no CM5 not working

2010-10-19T15:41:34+01:00

Obviously not, my bad. The TxD blinks, the RxD doesn't.

Statistics: Posted by clusher — Tue Oct 19, 2010 3:41 pm

USB2Dynamixel with no CM5 not working

2010-10-19T15:37:53+01:00

Is your answer to 1) correct ? Normally in no response case, TxD pulses and and RxD is off.

Statistics: Posted by i-Bot — Tue Oct 19, 2010 3:37 pm

USB2Dynamixel with no CM5 not working

2010-10-19T14:59:22+01:00

Well, this RoboPlus software is really practical, I hadn't tried it yet.

As for your questions:
1. By using the search option of the Dynamixel Manager, I only see the RxD led flashing, the TxD doesn't blink. This is done with all the 18 servos and powered by the CM5.

2. By using the RoboPlus Manager, and connecting the USB2D to the CM5 and setting it to use RS232, everything works fine, all devices are recognized and both LEDs are lit.

Statistics: Posted by clusher — Tue Oct 19, 2010 2:59 pm

USB2Dynamixel with no CM5 not working

2010-10-19T13:17:38+01:00

Does the USB2Dynamixel work OK in RS232 mode to connect to the CM-5 ?

Do the TX and RX LED flash on the USB2Dynamixel ?

Statistics: Posted by i-Bot — Tue Oct 19, 2010 1:17 pm

USB2Dynamixel with no CM5 not working

2010-10-19T12:50:07+01:00

By now I have tried the following:
-Using the CM5 for both communication and power, everything works fine, all servos are detected and move. So the servos should be alright.
-Using the USB2D for communication and either the CM5 or batteries for power, the servos move but they don't respond. This happens with one servo or multiple servos in the chain.

Statistics: Posted by clusher — Tue Oct 19, 2010 12:50 pm

USB2Dynamixel with no CM5 not working

2010-10-19T12:39:50+01:00

Did you try with just a single AX12 ? Maybe one has gone bad in the chain.

Statistics: Posted by i-Bot — Tue Oct 19, 2010 12:39 pm

USB2Dynamixel with no CM5 not working

2010-10-19T12:16:28+01:00

Just after checking if the 1 and 3 pins of U3 are connected (they are), I decided to go back a step, and I reassembled the Bioloid, connecting the CM5 to the bus just like usual and using the USB2Dynamixel for communication. It didn't work, it happens exactly the same thing: the AX12 obey commands but aren't answering (or the USB2D isn't getting the answers...). I guess all the other posts are now meaningless...

So, like House would say: "New symptom. Differential?". It seems I blew something up in the USB2D? Or can this be something else?

Statistics: Posted by clusher — Tue Oct 19, 2010 12:16 pm

USB2Dynamixel with no CM5 not working

2010-10-19T12:01:38+01:00

The FTDI Latency is usually set to either 1 or 16 millsec, either by software, or in the advanced driver config settings. Should not be a problem if you are waiting longer than this.

You might check the switch is working OK. In TTL mode pin 1 of switch U3 should connect to pin 3 of switch U3.

Statistics: Posted by i-Bot — Tue Oct 19, 2010 12:01 pm

USB2Dynamixel with no CM5 not working

2010-10-19T11:47:50+01:00

Sorry, I don't have a diagram. The pullup is R8 in the USB2Dynamixel, 10K to 5V from the data pin. it is close to the TTL connector (J3) and the TTL transceiver (U5).

Statistics: Posted by i-Bot — Tue Oct 19, 2010 11:47 am

USB2Dynamixel with no CM5 not working

2010-10-19T11:30:42+01:00

Update: I installed the RoboPlus and ran the Dynamixel manager. I used the Advanced Search to search all baudrates, and it came back empty, no Dynamixels found.

@i-Bot: do you know where I can find the USB2Dynamixel circuit diagram? I need to show it to my supervisor so he sees the pullup resistance...

Statistics: Posted by clusher — Tue Oct 19, 2010 11:30 am

USB2Dynamixel with no CM5 not working

2010-10-19T11:10:52+01:00

I have no idea about the FTDI latency... actually, I have no idea what that is.

The controller is written in Python and it waits up to 1 second before calling a timeout (using the CM5 I had it at 300ms and I increased it to see if the response was taking too long). The port is configured for 1Mbps, just as it was when the power came from the CM5.

Statistics: Posted by clusher — Tue Oct 19, 2010 11:10 am