ECE497 Notes on Creating a Beaglebone Cape
This will be the introduction to the page
The first issue that must be tackled is what exactly you want on your cape. There is a Google Spreadsheet that lists most Beaglebone capes that have been completed or are in the process of being completed. If the cape you are building does not have components on it that are in the repository, it is probably time to ask yourself whether the beaglebone supports the hardware you have selected.
Also, if your cape idea is really similar to one in the repository, I wouldn't get too down about it. Paypal is really similar to Google Checkout, Wirecard, and Moneybookers, but continues to be the standout internet money handling service for various reasons. Basically, I would suggest continuing to work on your idea. Especially if it offers something unique that the other solutions in the repository do not include.
Eagle CAD is an open source schematic layout and PCB editor environment that is used by most of the PCB open source community. You can find the latest version of Eagle here.
First Step: Prototyping
No Beaglebone cape is known to work until all of the suggested components are prototyped together with various development boards and a Beaglebone. Texas Instruments has many development kits listed on their website product pages. For example, if you navigate to the page for a common MSP430 Processor you will find on the right side of the page links to evaluation modules, development tools, and other information.
The other place to look for prototyping information is on the product page itself at vendors like Digikey, Mouser, and Allied Electronics. The MSP430 that we just looked at on the TI website can also be found on the Mouser website where you can buy it for $2.00. See also that the Mouser website has information such as a datasheet and schematic footprints for the specific product.
Building a Schematic
Eagle CAD is a fully featured CAD program that can be had for the low price of $0 as long as you are okay with these limitations:
- The useable board area is limited to 100 x 80 mm (4 x 3.2 inches).
- Only two signal layers can be used (Top and Bottom).
- The schematic editor can only create one sheet.
Pads and footprints are the metal conductors that the components going on the PCB are soldered. An example footprint is shown below for an MSP430 processor.