We’ve got a couple ways to pass signals between Arduinos sitting next to each other on the workbench now, or even 50′ away via a wireless dongle. But what if you need to get signals from 1000′ away or more?
That’s where a robust wired system based on RS485 can help. As a physical protocol, RS485 won’t get you there alone – you’ll need a communications protocol built on top of it to actually pass data. This week, we’ll look at DMX, the most common control protocol in the entertainment lighting field, how it relates to DMX , and how you can use both to pass messages long distances.
- RS485 fundamentals
- The OSI Model
- DMX (Digital Multiplex)
- Network Topologies
- Singalling and Addressing schemes
- Transmission lines, impedance, and ternimation
This week we’ll be making extensive use of the Conceptinetics DMX Library to handle DMX communication. You can download it from the link above. There are several published libraries that handle DMX, but this is the one I’ve had the most success with.
DMX Basic Send
DMX Basic Receive
DMX Knob Send
DMX Knob Send Dual