related to this topic
sorry for reviving this old topic.
I’ve got an Lynxmotion AL5D with the SSC32 Controller Board.
It works fine while being controlled by my windows laptop and the FlowArm software.
Our plan is to control the arm with an Raspberry Pi 3 via the USB inout of the SSC.
I’ve allready read a lot about this topic but none of the solutions work for us.
First i think i need the driver for the USB to Serial converter on the SSC but this seems not to be provided anymore?
Does anyone have an SSc32 working via USb with the RasPi 3?
Thanks a lot
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That sounds good. Will you be using Raspbian or some other standard Linux distribution? Also, will you be using Python (recommended) or another programming language?
Which solutions have you tried up to now? I might be able to offer advice once I know more precisely what didn’t work you.
As mentioned in the other post, connecting the SSC-32U board to most Linux distributions should create a file to access the port from.
In most cases, this will be something like “/dev/ttyUSB0”. The drivers required are part of most distributions already and therefore there is nothing to install.
You can try the Python examples here for a quick test.
I only tried the examples above on the RPi 2B+, but there should be no significant different with the RPi 3B+.
Let us know if they work for you (and if you can find the “file” for your USB interface). If not, we can prob. try it out later.
thanks for the fast answer.
I dont know the exact approaches any more, but the main problem was that I always had to find out in which USB-Port the SSC is connected and the Shell didnt find it.
I’ll check you solution on Monday and reply then again.
Sorry for the late answer.
Yes, we use the standard Raspian installation which was preinstalled on the Pi’s SD card and program it using python
Very nice examples. Thank you! They work perfectly!
Another Question. We want to know, which force/moment the Servos use.
Is there Any onboard possibility in the SSC 32 to geht this out?
You mean you would like to know the torque produced? Please note the SSC-32U sends position commands (through the RC control signal). The internals of the RC motor typically has a controller based on a position input (either potentiometer or magnetic) and control the voltage magnitude and direction provided to the DC motor inside.
Torque/moment/force never enter the equation directly in such servo motors. Some more advanced smart servomotors do include torque sensing (typically calculated indirectly by measuring current used) but this would not work with the SSC-32U.
Therefore, this would not be possible with the SSC-32U and standard RC servomotors since those motors do not even have that data (torque) available.
Do you know intellgent servos, which work with the AL5D and the SSC-32U?
How do you get the troque from the intelligent servo?
Short version: No.
While we do carry many intelligent servomotors (see here) or “smart servos”, they have all different case and output spline designs which means none of the hardware making up the robotic arm will be compatible with any of them without significant redesign. The exception to this would be smart servos with the right specs that fit exactly the current RC servomotors used (very unlikely; I am not aware of any).
There is also a second significant issue (see below).
If you want to keep the total price of this entry-level robotic arm reasonable, you have to use lower-end smart servomotors. Unfortunately, most of them really only report current use and the sensor is too flaky to provide a good approximation of the torque (since it needs to be derived) (i.e.: you’d get something like “no torque, some torque, lots of torque”). Some smart servos do have proper sensors in their electronics to get a good torque estimation (and do torque control) but then the cost goes up dramatically (i.e.: you need to go into semi-professional smart servos).
thank you for your detailed answer.
I thinkwe will try to inplement some angle encoders.
With those we will be able to close the loop of our Control Model.
I will report, how this worked.
Hi, I am a begginer in Raspberry Pi, Python and Robotics but love to try and learn more. I need the Python code example to be able to start. But the links in this article is not working. I have trying to google for this code example but not find anything. All help is very appreciated. /Rick