Kegboard Overview

This page describes Kegboard, the Arduino firmware for Kegbot.

History

The Kegboard is the most important device in a kegbot system; a reliable Kegboard is essential to accurately recording all pour data.

The current Kegboard is based on the popular Arduino AVR development board, and reflects several improvements from previous designs:

• Onboard in FT232 serial-to-usb converter
• Completely programmable via USB; no special programmer needed
• Plenty of I/O, including two external interrupt pins (pulse counting)
• Free C compiler and large standard library
• Widely available, many cheap clones

In addition to all of the above advantages, we decided to use an Arduino (rather than rolling our own controller board) simply because it takes a lot of hand assembly, soldering, and debugging out of building a Kegbot. You don’t need to be an experienced electrical engineer – or even own a soldering iron – to build a working Kegboard!

Features

Primary features of Kegboard include:

• Two independent flow meter inputs (monitor up to two kegs from one board)
• Two controllable relay outputs
• Support for any number of DS1820 temperature sensors
• OneWire bus master dedicated to device detection (use iButtons to authenticate to Kegbot through the kegboard)
• Documented protocol (Kegboard Serial Protocol Reference) for interfacing with software; supported by pykeg
• Easily built from widely-available Arduino board; no hardware programmer necessary

Parts List

The full bill of materials (BOM) for a Kegboard setup is show below.

Qty	Cost Each	Description
1	$35	Arduino USB Board
1	$3	USB cable
2	$35	Vision-2000 Kegboard Flowmeter
2	$5	DS18B20 Temperature Sensor
4	$0.25	5kohm Resistor (flowmeter and temperature sensor)

A basic kegboard setup includes:

• One Arduino Decimilia (or similar) AVR microcontroller board. This board can be purchased for around $30 at SparkFun.
• (Optional) DS18S20 or DS18B20 temperature sensor(s).