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Crumboard shield

Shield + small breadboard = crumboard

Crumboard shield is a prototyping shield designed for Jaluino. It embeds a small breadboard (thus the name, crumb-board...), two LEDs and two Push-buttons.

This shield is useful to test new hardware designs. It's also a nice base to learn how to use Jaluino and get started with PIC microcontrollers, experimenting very basic tutorials such as famous "blink-a-led", and read input from a push-button. Definitely a must-have!

Schematic and PCB

Crumboard includes two LEDs and two push-buttons, as exposed in the following schematic:

Figure 1. Crumboard shield schematic

LEDs and push-buttons can be activated using jumpers JP1, JP2, JP3 and JP4.

PCB shouldn't be a problem to build. You can access 1:1 scale Crumboard PCB PDF format, on Jaluino SVN repository. You can also use Crumboard labels (as PDF version), to stick on the board, in order to get a nice board as shown on photos (TODO: link to labels howto tutorial).

Figure 2. Crumboard PCB

Building Crumboard

Crumboard is quite an easy to build. Since Jaluino is aimed to be cheap, we also give special attention in order to provide this prototyping shield with minimal cost.

Building PCB itself isn't explained here, the following step-by-step focuses on how to deal with integrating the breadboard. You can buy a small one that would fit within shield connectors, but it often the same as a standard one. Some standard breadboards can be cut to fit shield size, for lower cost...

As first step, you'll have to find a breadboard like the one shown on the photo. It's a very common model. Be sure it can be cut.

Start to draw a line with a black paper. This is where you'll cut the breadboard. You need to get a length of about 2,7" (6,8cm), just measure what you need on the board itself.
Cut the breadboard, using a metal saw. Cutting is easy, just make sure it's straight.
As shown on the photo (and as drawn with pen), cut on a holes row.
Once cut, you should have something like this.
Depending on your breadboard model, you may need to remove one power lines part. Usually, you have two of them, on the left and right. Keeping both may give a breadboard too large top fit within shield connectors.
With one power lines part removed, breadboard will fit perfectly... Make sure to also remove the small remaining plastic part to get a clean surface.

You're done, just stick it between shield connectors. Some breadboards have a sticky surface, but it not, just use some strong glue.

Now the best for the end, you can build two crumboard with one standard breadboard ! Having multiple crumboards can be very useful when you work on multiple projects and design versions. Switching between them is easy: unplug a crumboard, plug another...

Using Crumboard

Crumboard can be used like any breadboard, but also provide LEDs and push-buttons to experiment inputs and outputs easily (TODO: links to upcoming Jaluino tutorials). This is an essential shield when getting started with PICs.

Crumboard can also be used to test rather complex designs, like this one prototyping a bluetooth device...