I have a question regarding the communication protocol and physical layer of how to connect the motors of a robotic arm.
I have 4 servomotors, Brushless. I need to select a motor drive for each one. The motors are: M1 shoulder- M2 elbow- M3 wrist- M4 thumb
in a daisy chain. I've seen that for similar configurations, people either choose RS485, or Ethernet or Ethercat or CanOpen, or even RS232.
How can I decide about this, which one to choose? Could someone summarize the drawbacks and advantages for these above?
I don't have very high requirements for the speed of the motors, I will use them for simple and slow rotations, and expect a power of 30W for each motor. Of course I would prefer the simplest option with minimum number of wires and I would try to avoid to much heating. I really need robust cables because the arm is moving.
Also considering that I will also embed a camera, is it better to consider Ethernet?
I am asking the above, because I see that sometimes people support RS485 over Ethernet, ie. Robotiq, but I also see solutions for Ethernet and even RS232 in some cases.
Thank you so much in advance ! If you need more details, I will comment back, but this is a rough idea I have right now.
thank you for your reply. I think that from these three, CAN is less expensive, Ethercat is the most expensive but also more robust, and RS485 is somewhere in the middle? Can you tell a price comparison more or less?
Then the issue is whether I need full or half duplex. In full I would opt for Ethercat or RS485. But which one of the two is easier to implement?
CAN would be also more simplified in terms of wires, and considering the fact that most microcontrollers have more often Can ports than RS485. But CAN is half duplex, and I think it would be important to have the simultaneous send and receive at the same line, for the motors in daisy chain, no?
Thank you in advance !