I have a very curious situation. I have two SSC-32 boards (older, Atmega8) and they are both acting the same way.
Servos aren’t holding position
Servos won’t always go to a new position
I’ve tried powering both from a 7.2V@2800 mAH battery and a 6VDC wall adapter with the same results. I can communicate with both boards using LynxTerm just fine. I can do a “ver” and get the correct response. It seems like too much of a coincidence that both boards could behave the exact same way and not be working correctly. I’ve tried moving servos to different pins, with the same result. I have the VL=VS1 and VS2=VS1 jumpers installed.
I have five servos connected - two HS-475 and three HS-645.
Is there some way I can check this out further and find out what is going on? I am using a parallax USB<>Serial converter that I also use when programming an Atom Pro without any problems.
Given that both SSC-32 can talk properly, it sounds to me more like something else going on.
Are we talking the same Servos? I would wonder if something is wrong with one of the servos, like an intermittent short… Does it work with 4 servos? I think I would try unplugging a servo and see if it still is not working properly, then try unplugging a different one…
I assume you have tried separating VL vs VS, but if not, that would be the next thing I would check.
I’ll try with just one servo and plug in each one and try with more. As far as I can tell, all the servos are good and should be working properly, but I will check this out in more detail.
I’m not sure what you mean by this. I have the VL=VS1 and VS1=VS2 jumpers installed, so it shouldn’t matter which connector I plug power in on.
I am getting some weird behaviors. I have put a single servo on pin 0 of the SSC-32, with no other servos connected. I tried each of 5 servos in turn, and each one behaved as I would expect - it goes to position and holds perfectly.
Then I started adding servos to consecutive pins and tested all connected servos. Everything went perfectly until I got to the fourth and fifth servos. Then all servos would lose their position and I could not get any of them them to move properly and hold position at least some of the time. I saw very inconsistent behavors after I connected the fourth and fifth servos.
What I was implying was to remove the VL=VS jumper, add something like a 9V battery or a wall wart to VL terminal, and separate power to VS(either 1 or 2) and see if that makes a difference. IE is the SSC-32 being reset due to voltage drop…
From your last post, sounds like a power issue. I would check out your battery. Or if you are using wall wart how much can it supply…
Yes, this is acting like a power issue. However, I am powering from the wallwart now instead of a battery, so power should be stable. I’ll connect the other SSC-32 up, do the same checks I’ve done with this one, and then see what separating VL and servo power does. I can’t do the power check with one SSC-32 because I have not replaced the two broken screw terminals yet - removed the old ones but have not soldered in the new ones yet.
I get a bit anxious when I have to plug power into these original screw terminals.
I separated VL and VS1/VS2, plugged battery into VL and wallwart into VS. Everything is working as I would expect now. I really don’t get why the wallwart could not power everything properly though. I expect everything to be fine with the other SSC-32 now, and will have to solder in some new power terminals on it soon.
This has changed the way I am going to power everything on both ASTRID and WALTER. I’m now going to use two 6V@1600 mAH batteries for servo power to separate each side of the SSC-32 and have VL on a separate battery.
I have the same one. It was strong enough to power 13 servos, the ABB, and the SSC-32. I know you said all is fine when separating the power, but I wonder what might be draining the power when just the wallwart is used. Either the adapter has lost its ability to deliver sufficient current, or something is drawing more current than used to. Perhaps the servos are under more load than they used to?
What ever it may be, it sounds like its working with separate power supplies.
Interesting. The wall adapter is brand new - I just got it in my last order. I’m only powering 5 servos and the SSC-32 at present, so I wonder why everything can’t be powered by the wall adapter now.
Yes, everything works wonderfully using separate power sources for VL and VS.
We would need to see the wiring to know if there was a problem with connectors, plugs, etc. We have three wall packs. 6vdc 2amp, 5vdc 2.5amp, 6vdc 2.5amp. I believe the 6vdc 2.5amp ones require a plug to be installed. If you got that one, did that go well? However if you got the 5vdc 2.5amp one it will be more likely to crash an SSC-32. Here’s why.
A regulated wall pack will provide the voltage it’s designed for up to the current rating. If you attempt to draw more than the rated current the result is the voltage starts to drop. It’s ohms law, it must be this way.
The 5vdc regulator on the SSC-32 is a low dropout unit meaning it will keep the 5vdc output with as little as 5.5vdc coming in. The 6vdc wall packs must stay above 5.5vdc for the 5vdc regulator to maintain 5vdc output. The 5vdc wall pack is already too low to be safe, and although it might appear to work, it’s already on the wrong side of right.
I was wrong. I received the 6V@2A wall adapter. I’m sure I ordered the 2.5A wall adapter, but will have to check my invoice to be sure. I got the 6V wall adapter on the order before this last one.
I do have this one also, but will be using it for my BeagleBoard rather than SSC-32 and such.
I’m sure I ordered the 2.5A wall adapter, but will have to check my invoice to be sure. I got the 6V wall adapter on the order before this last one.