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The only way to debug code like this, is to print out the intermediate state of the variables, for each time step, with appropriate mark-up to know what-and-when, and then go over it with a...

It's quite likely that the problem is some combination of the Python serial implementation, and the U2D2 device. Request/response turn-around time will just take a while, as far as I can tell.
I...

Yeah, logic is fun!

FWIW, the Teensy 4.0 and 4.1 microcontrollers run at 600 MHz these days, and do DMA for you if coddled just right, and their development environment plugs into the Arduino IDE...

This is at the same time totally awesome, and insanely scary :-)

Modern microcontrollers, with interrupt triggered pins and flexible I/O, are almost always able to "take a thing in" on one side,...

Honestly, the gait they show during development doesn't look like anything special, but once they get the more fully featured bot with all the make-up on, it looks pretty good!
...

How do you run the network normally?
You should be able to just run it the same way you run it for testing.
Then build a simple bridge that publishes the output of the network as a topic.

Sounds like a good deal!

That looks like a monster :-)
What poor lawn tractor had to donate its heart like that?

And on that note: https://forum.mechwarfare.org/ !

You don't need SLAM, because you can already build a map ahead of time.

You might want to use something like a couple of ultrasonic sensors to measure distances to edges, and perhaps a...

It may be that the best way to fix that is to learn the language and fix the errors/warnings. They're generally not particularly hard to fix, once you're into it. You could even provide a patch for...

That's actually pretty crazy. When a car battery is low, the alternator will have to produce a fair amount of current for a fair amount of time; I wonder if you can kill the alternator in your car by...

The best way to learn ROS is to start picking apart modules and see how they work, then start writing your own modules (perhaps just something dumb that talks to an Arduino on a serial port to flash...

Why do you think you only have two unknowns? Two drive wheels per robot, times two robots, equals four unknowns.

This is assuming the robots are attached with an articulating joint. If the joint...

The device is a USB serial port converter plus some electronics. It should work just fine with anything that has a USB serial class driver, especially if it runs Linux. The Pi should be fine....

The Discourse forum has been somewhat active, although the national shutdown has kind-of put a damper on any activity ...

https://forum.mechwarfare.org/

I don't know where to find them used, but the DYNAMIXEL XL430-W250-T is only $50. You'll also need some way to speak RS-485 with it -- a U2D2 or some wiring with an Arduino and a transciever or...

The question is how many degrees of freedom each joint has, and how many degrees of freedom you want to solve for the end effector.
If you have only three degrees of freedom total, and only need...

Also, don't remove a question just because it's answered. Others on the internet have the same question. If it's not preserved in the thread, google won't find it the next time around, and the cycle...

~ is the C/C++ bitwise-not operator. Yes, this is "1's complement"

What is the actual challenge here? You can't just use a 74241, you need a USB UART adapter, which shows up as a COM port in Windows. Then you point the Robotis software at that COM port. Then you...

I just set return delay time to 0 or 1, no matter what the baud rate. I do add some parameter variation based on the specific joints; it's an interactive tuning exercise.

Some microcontrollers need some time to turn around the RS-485 bus after sending the commands, so the return delay parameter makes sure the microcontroller has time to turn off the transciever and...

That sounds fantastic!



Have you done the torque calculations? Will 9g servos be able to hold this design without overheating?

If you need to ask about signal quality, then it's unlikely that the added fragility of 4.5 Mbps will help you at all compared to something safer like 1 Mbps.

To know what "too long" and "too...

Unless you truly need 360 degrees of motion (not 359.9) you don't need wheel mode.
You should just center the formula for "sent parameter from desired angle" at 0 degrees == 2048 sent parameter....

The 360 degree position is valued at 0. Unfortunately, you can't actually get QUITE to that position -- you'll get to (4095*360/4096) degrees. Protocol 2.0 has a "multi-turn" mode that may help if...

For hobby servos, I have no idea whether they even have a thermal cut-off, or if they just let you run them until they die?

150F (about 65C I think?) on the actual core/windings of the servos is...

For the Dynamixel servos (not Dynamixel Pro) the connector is rated at 3A continuous duty.
The wires that come from Robotis are 22 gauge.
This is slightly under-dimensioned for the heaviest duty...

Are you talking about the voltage on the RS485 bus itself?
That's covered by the specification for RS485.
Or are you talking about the host side, where the MCU talks to the transciever?
The modern...

The rubber band has enough tension if you can pluck it with your finger and it sounds like "twang."

Yes, torsion springs add more torque in one direction. But, if your robot is standing against...

Yes, that sounds exactly like an output that's under no load, and thus the PID controller is over-eager.
Either add some load on the servo, or tune the PID to be sloppier (but then of course the...

The PID controller may be overshooting and re-correcting back and forth.
Assuming this only happens when they're on, and torque is enabled.
If you disable the torque, does the sound go away?
...

In the Arduino API, "transfer" returns the byte that came back while it sent the argument byte.

Bob's Used Cars sell so many kinds of used cars and trucks, which one would you recommend?

I recommend that you buy the one that seems to work for your application.

If you have a hard time...

The difference between C=60 and C=75 doesn't matter at all.

Also, at those levels, it's very likely the batteries are rated "optimistically" ("this is the largest possible current the battery...

The current capacity of a battery cannot "push" current into a circuit. The circuit draws as much current as it's designed/made to do at the voltage you provide it. If the power source cannot keep...

Net-like sleeves are called "cable sleeving" or "cable sheathing."
https://www.mcmaster.com/cable-sheathing/
https://amzn.to/30f5w8y

If you need custom cables, you'll want to buy the crimping kits for the connector series from the manufacturer, and your own wire to crimp the cables onto.
The main challenge there is generally the...

I suggest the best forum to ask this in is https://forum.pjrc.com/forums/3-Technical-Support-amp-Questions