Friday, August 3, 2012

3 Useful Things to Know about the BeagleJuice, 2nd Gen

I got a few very good questions about the BeagleJuice, 2nd Gen from earlier this week, so I thought I’d answer them in post form.

What are the specs on the I2C pins on the BeagleJuice?

The I2C pins (GND, Vext, SDA, and SCL) are exposed for custom headers or wiring. After bugging Chris several times, he decided to just draw me a schematic instead. The range of operation is 1.8V to 3.3V. Currently, there are drivers coded for Android/Linux and OMAP, but it could be hacked to anything that talks I2C.

BeagleJuice2 I2C Diagram

What else can I power with the BeagleJuice?

The BeagleJuice comes standard with the 2.1mm barrel plug, which works just fine with the 5V barrel jacks on the Arduino, BeagleBoard C5 and xM, PandaBoard, as well as the BeagleBone.


That said, it is in fact just a 2-pin molex connector at the end, so Matt spliced up his own USB micro cable, put some heat-shrink on the tip, and voila! The BeagleJuice now charges anything that takes 5V – my phone, or even the Raspberry Pi (when mine finally arrives!).

What’s with the strips of LEDs?

Aside from the fact that LEDs are always fun, they actually serve a purpose.


The ones on the left are battery charge status indicators, which were inspired by Chris’ Macbook Pro battery meter. (Sorry the picture is a little blurry – I tried to catch it as the lights were moving up!)


There are a couple more “easter eggs” on the BeagleJuice, 2nd Gen – mostly holdovers from things Chris, Mike and I were working on here at the lab. Post your thoughts or guesses to the comments, or just send me a note – justin dot huynh at liquidware dot com

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