Breadboarding a Raspberry Pi

Question

Ok, long time reader first time asker on this parcticulair stack-exchange. I am rather new to electronics, I've done some simple projects like Blinking Lights, alarms that go on when its dark and a Joystick Gamepad (with Arduino).

However, I am experianced in system programming, I've written a bootloader (x86) for fun, read assembler language for a living and have hacked some code for kernel modules.

For my most recent projects I got rid of the arduino and used a breadboard to build the entire board (same setup as the arduino though). I've created a project, got the breadboard prototype to work and now I am ordering a number of PCBs (seeedstudio) to get the real prototype going.

While I am waiting for these boards and the components to arrive I've started a project with the RaspberryPI, created a embedded linux for it and I've been playing with the GPIO. Now I wonder, how hard is it (and what is required) to breadboard a raspberrypi so I can eventually also get my own boards created for beefier projects.

TL;DR) What should I learn about before I can assemble a RaspberryPi on my Breadboard? As I can't imagine it is as easy as breading the Arduino

Note: I've read, http://arduino.cc/en/Main/Standalone

Answer 1

I've been dabbling in electronics since the 1970s and had products used in nationwide broadcasting chains, reviewed (sometimes favourably!) in hi-fi magazines and (possibly soon) headed into orbit, and I would still consider breadboarding a Raspberry Pi a major project.

Find a middle ground : take a look at an ARM CORTEX CPU running at 50 or 100 MHz and learn to use that. Then when that is second nature, consider taking another look at the Raspberry Pi (or whatever has replaced it in the meantime). A good starting point is the TI Launchpads (Stellaris, now Tiva) or Hercules for 100 MHz and high-reliability hardware. Or similar processor devkits from ST Micro or NXP. When you grow beyond the Launchpad board itself you will have experience with a more advanced CPU system than the traditional Arduinos, and it's in a package which is much easier to breadboard than the Raspberry Pi. (And at this level, "breadboard" really means layout your own PCB).

You won't even get a datasheet for the R-Pi's processor without serious negotiations (probably involving six digit numbers) with Broadcomm.

Alternatively, use the R-Pi as a component - a complete subsystem in your design that removes the need to repeat a LOT of engineering and lets you concentrate on your specific application; focus on what makes your hardware + software app unique.

Answer 2

AVR and other microcontrollers in that class offer flat pack and through hole versions that are easy to use for small volume assemble in your basement or garage type stuff. The raspberry pi is not only BGA but BGA on BGA. You are not likely to have success without the right equipment and experience. BGA is hard enough, but for that Broadcom part the processor is a bga with pads on the top then the DDR is a BGA that sits on that.

So even if you had the equipment somehow or access to it. there is the issue of Broadcom. They are in the chip selling business, no doubt they went ahead with the Raspberry Pi to ultimately sell more chips as well as improve their name. But they are secretive you want to build something with broadcom chips I dont know but I would assume you have to be big enough for them to see the are going to get some volume out of you and then of course you have to sign all the right NDAs in order to get the info you need to build the boards, etc.

As already mentioned, if you are not a big company ready to do volume, then you should plan on building boards that mate up with the existing raspberry pi boards you make a daughterboard or the raspberry pi is a daughterboard to your board.

Answer 3

The Raspberry Pi is based on a System-on-Chip (SoC) device that is impossible to use in a breadboard because of its high pin count and strict timing requirements.

What you need to do is treat the entire RPi board as one component in your breadbaord setup, using the breadboard to implement the application-specific I/O. Then, when you are ready to create a unified PCB, you would incorporate the relevant parts of the RPi board directly into your board layout.