Or do you want me to download the LSS - Configuration Software to the computer then change the ID of LSS then connect them to the raspberry?
1 Like
If you have a Windows-based PC that would be best.
You can obtain a copy here.
Yes, this is a possibility. Since youâve been trying to do this unsuccessfully though, I think it is time to try a different approach to help you move forward with your project!
Yes! 
Yes.
To be fair, you could do the changes from the Raspberry Pi directly (without using code), too.
From the RPi, open some kind of serial comm terminal to the port at the appropriate baud rate. Plenty of software exist to do this so search online for one that fits your needs and distro.
Then, following the steps above, replace the scans with #254QID\r (since only one LSS is on the bus, only one answer should come back). You can then use a #[id from response]CID[new id]\r to change it. Then send a reset to the LSS using the old ID. Repeat for the second LSS (one on the bus only).
You can then try some D commands and QD to see if they answer properly with their different IDs.
1 Like
Hello,
After scanning and change the ID to 1. I donât see any UPDATE button or something to apply the change?
Or press scan again?
Thanks
1 Like
Never mind. Found it
1 Like
For reference to anyone else reading this, you can find more details here. The update button is on the bottom right corner of the the LSS Config.
Good morning,
I have changed the ID and made them work as I expected successfully. The issue is solved. Thanks for your help.
There are two motors and every time I turn the power off and turn it back on there is one motor that always moves back to zero from wherever it is and returns the position -1 or -2 (I did not remember what I have done with it) cause I got it from the first order. The another one (I got from the second order) doesnât. How to set it up so that it moves back to zero from wherever it is? I like both move back to zero from where they are when I turn power on.
Thanks
1 Like
Great!
A LSS going back to 0 (or any other position, really) on power-up means you configured it to use a âfirst positionâ. This is a position that is âplayed backâ to the LSS on power-up before accepting any commands. It basically simulates sending a âDâ command to the set position. You can read more about that setting here.
As a side note, you should really read that entire page! It is full of useful information about all the features you can use/configure/query of the LSS!
If you manually query both of your LSS with QFD youâll see what values they are set to. Most likely one is set to 0 and the other will return DIS (i.e.: not set).
If may be worth mentioning that while the LSS is operating the virtual position (the value you use/query with commands like D, QD, CDF, etc.) can go for to very large numbers. But, on power-up, the 0 (or whatever you set the CFD to be) position the LSS will go to, while it will always be the same physically (same angle of the horn vs the case), it may go in an expected direction.
This is due to the absolute magnetic encoder used in the LSS internally. This encoder, at power-up, can only say where it is in relationship to the LSS, but it does not know about how many times it turned previously before the power cycle. Therefore, if using an assembly where the LSS cannot turn freely in both directions (most robots are like that), make sure to power-off the LSS in a position where it will be safe to rotate to your CDF.
At power-up, the LSS will setup/report a position in the range of -1800 to 1800 (centered on the offsets) if you query it with QD. When you set it to go to 0 (ex: by configuring it with CFD0), it will move using the shortest path to the target position. So if during its last operation it ended in a position where it would power-up with the opposite polarity (ex: it powers downs at position 2700 or 270.0° but will power-on at a negative value, since 2700 is outside of the startup range) you may be surprised by the LSS moving in the opposite of the expected direction when CFD is âplayed backâ.
So, basically, try your setup and run a few tests just to see how it goes with your use case! Just keep in mind the position and the potential impact of power cycles to your assembly (i.e.: loosing the virtual position between power cycles).
1 Like
Thank you.
I appreciate it.
Everything is in place now. Just order some more brackets then goâŠ
1 Like
Good!
Glad to see this resolved for you⊠now you get to the fun part: the actual project! 
You always need more brackets⊠
Feel free to share about your project here. Iâm sure others in the community would be interested and if you ever need more help in the future it would probably make it easier for others to get involved, too!
Good luck and enjoy!
Hello,
I got a problem about the position.
Saying I have two points. A {X=20 (2degrees) Y = 45} and B {X = 55, Y = 60}.
If I start from HOME (zero degree for both motors X and Y), then I can move to point A by using command XLSS.move(20), YLSS.move(45) and the same with B. I can get very close to where A & B are.
If I am at A position and I want to move to B. I use XLSS.move(55), YLSS.move(60) or if I am at B and I want to move back to A by using XLSS.move(20), YLSS.move(45) then I never get to the position as I expected.
Any ideas of where am I missing? (absolute and incremental positioning)
Thanks
1 Like
Yes.
Yes I have. You are moving by 2-3 degrees. Such a small amount of movement will inevitably (in EM=1 [Motion Control Mode], the default mode) never travel at full speed and therefore not get to the exact position due to lack of torque. In DC motors, torque and speed are closely related with the voltage level (used to control the speed).
Therefore, there are a few options:
- Increase stiffness, either or both AS and AH (see here)
This will make motions a bit more âjerkyâ but also force more power to reach the desired positions. Increase by 1 at a time and test with your setup. - Use EM=0 and play with advanced motion control settings.
I recommend trying option 1 first. Also, you can change AS and AH between moves as needed, too.
1 Like
Thanks Scharette,
Here is my parameter that I set for my both motors before I post the question:
SetMaxSpeed(50)
SetAngularStiffness(2)
SetAngularDeceleration(80)
Are they OK?
1 Like
Iâd recommend that you only modify angular stiffness and angular holding stiffness instead. And youâd probably want to increase them (especially holding stiffness) to a value higher than the default.
If I remember correctly the default values are (in EM=1, default control mode):
AS = 0 (all models)
AH = 4 (ST); = 4 (HT); = 2 (HS)
1 Like
Hi,
I got the error this morning:
STraceback (most recent call last):
File â/home/pi/LSS_Library_Python/src/test.pyâ, line 15, in
lss.initBus(CST_LSS_Port, CST_LSS_Baud)
File â/home/pi/LSS_Library_Python/src/lss.pyâ, line 21, in initBus
LSS.bus = serial.Serial(portName, portBaud)
File â/usr/lib/python3/dist-packages/serial/serialutil.pyâ, line 240, in init
self.open()
File â/usr/lib/python3/dist-packages/serial/serialposix.pyâ, line 268, in open
raise SerialException(msg.errno, âcould not open port {}: {}â.format(self._port, msg))
serial.serialutil.SerialException: [Errno 2] could not open port /dev/ttyUSB0: [Errno 2] No such file or directory: â/dev/ttyUSB0â
How to reinstall the the file /dev/ttyUSB0?
Thanks
2 Likes
Never mind. The issue is fixed.
Just restart the raspberry.
2 Likes
1 Like