SCC-32 question for a beginner

Lynxmotion Electronics & Software
1

Hello, I new to configuring these controllers. I have had bad luck so far with them. I have a few questions.
What are the power and amp requirement of “VS1” on controller if you are using it for the “BiPed” project. I have been told that my main problem has been power. So have are the specs?
When the controller has power first applied to it how long does it take before it can take commands?
Can you use another program to send commands to the SCC-32 besieds the Lynx-Term?
If you are using this programe and use the Sequencer to see if any of the servor are moving. Does this brake any thing?
How long does the SCC-32 take to process commands?
Do you need to enable the ports first, if so how “#0 p1500” should this do it?
The instruction book shows “#0 p1500” as a command to tell servo on port 0 to move to 1500. First is this the right syntax? Next if the servo is at 1500 what will it do?

thanks for any reply.

2

The power and amperage requirements depend on the number, types, and loading of the servos being powered by VS1. The board itself is capable of handling 10A peak each for VS1 and VS2–I have tested with a 10A load and had no significant heating after several minutes. I have not built any bipeds, but in general I would allow 200 mA or so per servo (can be much worse under heavy load).

The controller is ready to accept serial commands as soon as the green LED comes on. The power-up initialization requires less than 10 milliseconds from application of battery power.

You can use any terminal program to communicate with the SSC-32, including Hyperterminal. One of the benefits of the ASCII command format is that it is easy to do basic checkout using a terminal program.

It is perfectly fine to send servo movement commands while the sequencer is operating. If the command addresses one of the servos used by the sequencer, then the sequencer takes precedence. Otherwise, the movement commands will be executed independently of the sequencer.

Command processing time varies depending on the length of the command. The worst case is a group move command involving all 32 servos. It takes about 6 milliseconds to process a 32-servo movement command, starting from the time the carriage return character is received. At the other extreme, a binary move command will typically be processed within 100 microseconds of being received.

The command processing times stated above are just the amount of time the SSC-32 needs to chew on the command to prepare to output the pulses. There are two other delays that come into play also. First, the servo pulses are repeated every 20 milliseconds, so even though the processor might be ready to output pulses based on a received command, it will not output the pulses until their designated time slot comes around. So it will be an additional 20 milliseconds worst-case (10 milliseconds average) before the pulse appears on the output. The other delay is the time to transmit the command. At 115.2 kbps, each character of the command requires about 86 microseconds. In terms of human perception, all of these delays are so short that they appear instantaneous.

The servo output ports are enabled by default, so a command like “#0 P1500” should work right after powerup. This is the correct syntax, but don’t forget the carriage return at the end of the command. The board does nothing with a command until it receives the carriage return.

The value 1500 represents a pulse width of 1500 microseconds. For most servos, this pulse width will cause the servo to move to its approximate center position.

Hope this helps.

Mike Dvorsky (SSC-32 designer)

3

OK, so none of that is happening. I have tried new 9v DC for the logic and a fresh 6vDC and it will not move after boot up. Some times after a bit it will move around crazy. I’m not getting any thing consistent in the way of moving the servo. If it is power then how long should one servo last with 6vDC? It seems to only work once, then not at all after that. I’m real frustrated. I got the board checked but I’m think by what everyone is telling me this thing should just work. It is not. All I’m trying to do is map out the servo movement. I will wait on getting it to walk. Any ideas.

4

Yea, it should just work… I tested that board myself. :stuck_out_tongue: I didn’t know you were still having trouble. Please send it back and I will replace it for you. The only thing I can think of. Ok?

5

OK, Cool. This has been burning me out. I have tried 6vDC and 7.2vDC (from my VeX) batteries I got a new battery charger. I have been running the SCC-32 through the Bot-Board too, with no luck. It worked at first then not at all. So then I took one servo to pin0 a 9vDC for logic on VS1 6vDC and 7.2vDC, I ran through start with #0 p1500 , nothing, then #0 p750 nothing. So could it be my commands? Can you give me the exact syntax for SCC-32?. Let’s say I just booted up the board and I have the SCC-32 hooked up with only one servo on pin0 a 9vDC for logic and 6vDC for VS1. What should I enter first? All I would like to see is it moving to 750, 1000, 1500 then 2000.

6

Just an idea…are you sure that your PC com port is set to 115200Kbps…and…are you sure about the two Bauds jumpers on the SSC-32 card ?..Hum ?..
another thing…if you use a 9V for logic and 6V or 7.2V for servos…don’t forget to remove the VL=VS1 jumper !

7

OK, from your post this is what I check

  1. On Window device manager, checked this
  2. On Lynx Terminal, Checked this
  3. Baud rate on board, both jumper or shunts are shorting so this = 1 1 :115.2
  4. VL (voltage logic) = VS (voltage servo), is removed
    Still did not work, I have tried many different setting to no effect.
    I use a terminal program for my work, I’m a network engineer. So I’m use to using this type of program. You type some thing in and some thing happens.
    Jim said to check the voltage on ABCD pins, I did that last night. When I was testing it. the servo moved.
    Thanks for you post, I appreciate any help. I am new to this type of stuff.
    I’m getting a great education on the inter-workings of this board. I just don’t have a lot of time to spend on this hobby between work and home life; so when I have time I would like to make progress in programming this thing not troubleshooting.
    But then again such is life.
    I really glad there is a form now.

Thanks again.
chrisC or Junk ( I like to collect stuff)

8

Your symptoms sound like a loose connection or other power problem, as others have also suggested. The only time I have seen this sort of behavior is when my battery is about to die. But, given the things you have tried to fix this, it is sounding more like a flaky board. I hope the replacement does the trick.

Off the top of my head, here are some troubleshooting tips for the usual types of problems.

**Power problems

If the green LED suddenly turns on solid and the serovs stop moving, there is probably a power problem. Weak battery, loose connection, short circuit, etc.

When the logic supply drops below 4V or so the processor will reset. The internal brown-out detection will force a reset before the thing goes haywire. The symptom of a processor reset is that the green LED will come on solid and the servo outputs will all turn off. If you are using the same battery for servos and logic, a weak battery might cause a reset whenever you send a move command. This is because the additional current draw from the servo pulls the battery voltage down causing a reset.

**Communication Problems

If the green LED never turns off when you send a command, you have a communication problem. Mismatched Baud rates, disconnected serial cable, wrong COM port, etc.

After power-up, the green LED stays on until the first valid character is received over the serial port, at which time it turns off. Thereafter, it blinks briefly for each received character. If the serial data is being corrupted somehow, the LED will fail to blink for bad characters (framing errors).

My usual sanity check for good communication is to use the VER command, which causes the SSC32 to reply with the firmware version number. It should work consistently.

**Servos Don’t Work

This is a lot less common than the first two. If you are using a separate servo supply, check the voltage on the servo header pins. Also, check the firmware version to make sure that you have the firmware for servos 0-31. There is a firmware version for servos 32-63; if you have that installed by accident it could be very confusing. Try connecting a different servo to the pin to make sure the servo is working. Make sure the servo connector is not connected backwards.

Good luck with this. I know from experience how frustrating it is when things don’t work the way they are supposed to–especially when it is something new and you are not 100% certain how it is supposed to work.

9

Yep ! VER command is a good idea to test !..any result ?
what serial cable are you using ?..are you sure to connect to the right com port ? com1…2…3 etc ? because lynx terminal can connect to a port which is not the one you put the card on…you must select the right one and click ‘connect’
What is the right one ? type ‘VER’ if it answer -> it’s the right one :mrgreen:

10

Serial port or COM port, I use this on my laptop ever day, I configure Cisco equipment. So I’m sure the port works. Cable does work becasue I can controll the “Mini-ABB” board with it. I have also used the same batteries, power connection cables and console cable that I have used on the SSC-32 that is funkey and work great on the “Mini-ABB”.
To test all this I ran this script
'Atom and Mini-ABB test servo
leda var byte
leda = p4
sound p9,[1000\2500,2000\2500]
low leda
pause 1000
low p0
pulsout p0,750
pause 20
high leda
Well it does work, I can take the value “750” and change it and reload the program, I works ever time.

I think it might be a VL problem too looking back over what everone has posted. I have taked out the VL batterey as a problem I have a DC transformer that can output 8 vDC.

Yes, “ver” was a command I issued to check. It did not yeild any out-put.

Thanks
CC

11

I got a replacement borad and all is well. I tested it for awhile, I will be working more later this week.

Thanks Jim for your time and fast responce.

12

I am at the point where i can not communicate with the board. The led doesn’t go off at all. I am running a 9v battery with the VL:VS jumper installed. I have two Futaba standard servos installed on 0 and 1. I am running Lynx Terminal. I am pretty sure it is a port issue. I am using a radio shack RS232 serial cable.

I guess i am trying to ask how do i verify the port? I am runnig windows XP, Dell ispiron laptop, i am plugged into the first female serial port all the way to the right looking at the back of the computer. That is way too much information but i wanted to cover my bases. I think the board is fine but i am just to green to know how to plug it in.

Oh, and i venture this problem is a side effect of no communication, when i type ver into the Term box, i get nothing back. And, when i click firmware button on the Term GUI all it says in current firmware version field is “ver”. I considered that the firmware was not properly installed but i doubt that.

Thanks

13

In case this helps: When I first got my SSC-32, I couldn’t talk to it - the LED stayed on, no response to chars typed in HyperTerm.

The solution was to add a “null modem” adapter to the serial cable.
The null modem adapter swaps the 2 data lines (pins 2 and 3).

I think I saw in the SSC doc that it expects a straight-thru cable. If so, then my original cable was a “null modem”, and adding a null modem adapter switches it back, so now it works.

Pete

14

That is good to know! Thanks. :smiley:

15

I can try the null modem. Acording to the box the cable came in, all the pins are the same on both ends. But ill give it a shot, thanks

West