Hi @Unobtainian,
Welcome to the forum! Are you part of the The In Theory Art Collective? Amazing stuff!
Wireless:
When you say app, do you mean Firestorm, or the Pixel Lights phone app? How did you set up WiFi for that, do you use another AP/router, or set one Pixelblaze in AP mode, and connect the rest? If that can be figured out, it might be easier, assuming WiFi will reach.
Wired expander:
Yes, fast data signals tend to pick up noise and have transmission issues with very long runs. It uses a serial protocol that works well over shorter distances. The expander has checks to prevent drawing garbage data, which improves the distance capabilities, or otherwise it would probably look very random and glitchy instead of drawing the actual pattern colors.
One way around this issue is to use a converter to a long distance protocol, like RS485, that is designed to ignore noise over long runs. It uses more wires, but can travel very long distances. It needs a receiver on the other end. RS485 can also handle multiple “drops” or connection points as long as there aren’t very long branches.
We’ve talked about this a little on the forum before for pixel data.
I would recommend picking up this cheap 5 pack of rs485 tranceivers (they can transmit and/or receive) https://www.amazon.com/Max485-Chip-RS-485-Module-Raspberry/dp/B00NIOLNAG
On the main set, where your Pixelblaze is located, the connection to the local expander doesn’t change. Install a tranceiver in that node and wire it up like this to have it transmit data:
VCC → Power 5V
A → long wire to second set
B → long wire to second set
GND → Power GND, and long wire to second set
DI → Pixelblaze data (also connected to the local expander)
DE → 5V
RE → 5V
RO → not connected
From there, you would run 3 wires connected to: A, B, and GND to the second set.
On the second set, install a tranceiver and wire it up like this:
VCC → Power 5V
A → input from first set, and continue long wire to second set
B → input from first set, and continue long wire to second set
GND → Power GND, also connect GND first first set, and continue long wire to second set
DI → not connected
DE → GND
RE → GND
RO → expander data input
The 3rd set would be wired much the same as the second set.
It’s better to run the A/B transmission wires as one long path than to create branches. If it would be easier to run 2 sets of transmission wires from the main set (like if it was in the center of the others), then you can use 2 independent transmitters.
The differential transmission wires work best with twisted pair, this is super easy to find as CAT 5 ethernet cabling. For your distances that wouldn’t be critical though.