Hey guys, here's a little thing I've been working on in my spare time. Still very much in the early stages, but I wanted to make a better way to control my auxiliary items in the jeep (lights, winch, etc.) so I whipped this up.
Here's the gist:
- 5x Automotive (Bosch-style) relay mounts, so relays can be replaced, and are easy to source (I usually carry spares in the jeep)
- 16Mhz Microcontroller, compatible with Arduino
- Self-temperature regulating via a small fan in enclosure (max board temp supported right now is about 115C)
- Monitoring battery voltage
- RS-485 interface for remote control in noisy environments
- Relay outputs can be controlled via software running remotely, or via mechanical switches for safety backup
- Relays start in known (off) position no matter what
- 15A draw per relay/40A board total*
- Linux/Windows/OSX control GUI (in progress, for using a tablet/computer in-jeep)
- Isolation between analog and digital sides to prevent damage to the control circuitry
* - Power source for relays can be input, or pulled from the board via a jumper. All relays can be run at 15A, if no more than 2 are pulled from the board - the other three can come from the battery.
I'll release everything (firmware, software, schematic/board, and cad files) open-source when I'm done. This is the first run of the board, so there's still plenty of work to go, but I'll post here as I make progress.
Note: this version is all through-hole so people who aren't yet ready doing SMD can put one together, I'll do an SMD version after al the basics are done, as the total cost will be a lot cheaper for those who can do it.
I'd, of course, love feedback or thoughts. I considered doing an Android version of the control software(not keen on iOS development), but I was able to re-use a bunch of Qt work I've done, so Android won't come until Qt gets better android support (soon, I hope). There are a large number of linux-compatible devices in the sub $100 range right now, so I'm not sweating it.
3D rendering of board:
Photo of 1st board assembled: