If you need to control LEDs remotely, say for an art installation, you have a few choices on how to do it. You can have a microcontroller near each group of LEDs, playing back a pre-programmed pattern. You can even go to extremes and have a single, tiny microcontroller controlling each LED! But the way professionals do it is with RS485 or RS422. This differential Neopixel transceiver and OctoWS2811 dual transmitter pair by Tindie seller oksquared is a great example of using existing, robust technologies to create a simple solution to the problem.
Note that both products can be used as the transmitter side, but only the transceiver can be on the receiving end. The transceiver uses the SP3485CN differential chip, and the octo-transmitter uses a pair of SN75174 differential line drivers. The OctoWS2811 board can send up to 8 Neopixel data streams at once, and so must be split into multiple cables if using all channels. This way, a single powerful microcontroller or SoC can remotely control huge numbers of LEDs. Putting the power supplies near the LEDs and having just a single cable coming in with data makes installation and testing much faster and easier. Plus, differential buses are much more resilient when it comes to EMI and other sources of noise, meaning long cable runs near other electrically noisy devices are a feasible solution. As a bonus, this transceiver also uses CAT5 Ethernet cable, which is already rated for installation inside walls and so is a very good, safe choice for the job!
So, if you ever need to drive a large Neopixel installation, pick up one of these easy-to-use boards and focus on your art instead of debugging serial connections! Contact oksquared if you have any questions about using these boards to drive your latest project.
