My team and I have been working with the SCC-32 for a few months now but have started running into some trouble.
We were running some sequences and the arm just started to turn off. We are running the processor of the 9v battery and the servos off the wall wart. We were running the arm’s motors (5 total) plus 3 more for other applications on our robot. When the robot is moving we are typically looking at 2A continuous, and when the robot is resting about 1.4A (the other three motors are always running to hold stuff up).
The robot has taken to just going limp, even with only the arm’s servos running.
Can anyone provide some troubleshooting advice?
EDIT: The controller isn’t really resetting, it just started sending a random ASCII character (the same one every time, y with two dots above it). The arm will also not respond to commands sent via putty (such as VER).
I’m using RIOS to control the arm and the sequences, when the arm died, I would close RIOS and open PuTTY to try to control the arm by hand and get it to talk with me, and it would not respond. When I am connected to via PuTTY it interprets what it is being sent as ÿ.
The green LED would come on, but it was not solid, it was flashing very very rapidly.
I am sure the jumper is has been removed, and I’m not sure if the battery is still good, when I get to my multimeter at home I’ll check.
If the light is flashing rapidly, it’s receiving data from somewhere.
What baudrate are you running at, and how long is your cable? (And how confirmed good is it?) Have you checked serial cable routing to make sure it’s not near something electrically noisy? RS232 is not particularly noise-tolerant by default. How loaded-up is the machine controlling the SSC32, and where’s it getting its data from?
Sorry - I hate answering your question by throwing a bunch of questions at you - just trying to give Jim some data to diagnose with.
If you’re running at 115kbit or something, I’d drop the baudrate way down and see if life improves. Some serial ports, most especially if you’re using a USB->Serial converter, just don’t like 115kbit. I’d try it at 38.4kbit and see if it behaves better.
Another thing to do would be to hook-up the machine running RIOS to another computer over serial using a cross-over cable (null modem, 2/3 cross) and use something like RealTerm (realterm.sourceforge.net) to capture the data stream on the destination machine. A quick examination of the data stream will quickly tell you if you’re getting garbage out.
Serial data can be “fun” to diagnose, but I’m betting with the rapidly flashing lights that you’re getting garbage at the serial port rather than the processor on the SSC32 dropping out. If it were legitimately restarting and then receiving data, the arm should spring back to the last commanded position, or to neutral and then the last commanded position…
