What would you like on your Kegboard Arduino Shield?
Our Kegboard firmware has been pretty solid these days, and we've been pretty happy with the features afforded by the basic Arduino Duemilanove board. So, the time has come to stamp out an Arduino "shield" daughtercard, making it as simple as AOL 9.0 to get your Kegbot online.
The First Draft
Shown above is the first draft of the schematic.
And the corresponding board layout (your author has not yet performed the board routing). Note that the shield intentionally hangs to the right and bottom of the carrier Arduino, to provide adequate clearance from the components below.
Current Features
Here are the board's current features, as of today anyway (this is all subject to change).
The First Draft
Shown above is the first draft of the schematic.
Current Features
Here are the board's current features, as of today anyway (this is all subject to change).
- Two RJ45 'keg ports'. Each RJ45 breaks out both flow meter inputs, the temperature sensor OneWire bus, and power and ground connections. Using a Cat-5 cable or two, all sorts of combinations should be possible: monitor two taps in one fridge with a single cable, or one tap and a dollar bill acceptor with both ports, or two separate fridges, and so on.
- LEDs at each keg port, which can be used to signal tap activity.
- One RJ11 'authentication' connection. This is wired to the OneWire presence-detect bus, and the pinout matches the famous blue dot receptacle.
- Onboard buzzer; right now, the kegboard firmware doesn't do too much with it (it chimes on powerup), but we could easily do a software update to add alarms.
- Socket for optional XBee transciever; read the kegboard remotely.
- Pins for optional board level temperature sensor; conveniently add ambient room temperature monitoring to your Kegbot setup by soldering in an extra DS18B20.
- Two 3-pin screw terminal headers, each with power, ground, and an LED-signalled general purpose output. Use this to interface with a relay board, external alarm trigger, or whatever.
What to add?
We'll probably spend a few more days tweaking the schematic and layout. Unless any great ideas pop up, the first batch will likely look something like this. (We're not sure if we'll sell boards, kits, or anything at all ourselves -- but we'll at least make it easy for you to order the parts and boards online.) Leave a comment if you have suggestions.
Appendix A: Kegboard v1.0
Back in 2005, in the bad old days before we knew about Arduino, SparkFun, and plentiful Eagle libraries, we put together the original Kegboard: Kegboard v1.0. Here's what it looked like:
(Image unscrupulously stolen from Make's coverage of a rare public appearance by the reclusive team Kegbot.)
The board itself featured a PIC16 micocontroller, a socket for an (expensive) FTDI USB-serial converter, and two relays. Compared to our current design, you could say it was a complete solution, though not with its problems (and higher cost). We might return to a 100% integrated board one day, after Kegbot takes over the world, but for now we're happy to build off of the Arduino.
Next: Facebot? Kegbook? It's your Kegbot drinks on Facebook!
Previous: "Tips" for your Kegerator: Kegbot, meet Dollar Bill Acceptor