PC-connected Teensy(s) for 30+ feet - connection, power, signal ?

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u_cap

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I am trying to find a good solution to connect several - possibly a dozen - Teensy nodes to a PC host.
The simplest approach would be to just connect them wired, to a USB hub, and run both power and serial.

However, eventually I will have to run wire lengths up to 10m and possibly beyond.
Is this even possible with stock USB2 cables (I found 25' max so far)? For power, data, both?

I might also have to add a power supply to each node (either because I can't run USB 5V that far, or because each nodes needs more than what the Teensy 3V3 regulator can supply anyway).

Does this still apply - mechanical modification of USB cable (cut red 5V) or Teensy (pads) is necessary?
https://www.pjrc.com/teensy/external_power.html
For Teensy LC and Teensy 3.5/3.6 ?

I looked for data-only USB cables, all I found was:
https://www.ebay.com/itm/182101117279

Is there any retail or DIY solution for "networking" a bunch of Teensies, or putting them on a bus?

Is there a better than "Serial" connection between PC and Teensy, over USB? Or would it make sense to investigate actual RS232 solutions?
 
10 meters is pushing the limits for USB, but can work. The USB spec defines a maximum delay, which translates into 5 meter cables between the maximum number of hubs. Longer cables tend to work, as long as you're not also using many hubs chained together.

I have personally used a 30 foot extender. It's similar to this one, but I couldn't find a link to the exact one I actually have. They're probably all very similar.

https://www.amazon.com/Your-Cable-Store-30-USB/dp/B0052EXWOK

The 2 other good options for longer distance communication are Ethernet (~100 meters) and RS-485 serial (~1200 meters).

With USB, all nodes need to be either earth grounded or floating. USB doesn't tolerate any difference in ground, which can become a real problem if you send power over those lengthy difference, since the power wires have some non-zero resistance which causes a voltage difference in GND between the 2 sides.

Ethernet uses isolation transformers, so it's very good at handling ground shifts. RS-485 chips usually can handle about 7 volts of ground shift, which is quite a lot. RS-485 optical isolators are also common, though they do require making sure your code has "turn around delay" before you begin transmitting.
 
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