How can I learn to build my own computer with Arm processors?

Is there a book(s) to learn how can I build boards like Rasperry-Pi ?

Is there a book(s) to learn how can I build boards like Rasperry-Pi ?

> Is there a book(s) to learn how can I build boards like Rasperry-Pi ?

Not that I know of - it would be many books worth of knowledge!

A word of warning before heading down this route. For most devices you can't easily build the PCB as a hobbyist - most Cortex-A cores are packaged in a BGA package with hundred of pins, requiring multi-layer PCBs which require specialist equipment to manufacture. To be honest even soldering surface mount components onto a PCB you've had made is difficult enough to do reliably. Most projects I know of design the board themselves and outsource the fabrication of the PCB and soldering to a dedicated manufacturing company.

Most "home projects" I've seen building tablets or home servers using Arm take an existing board, such as a Rasberry Pi, Arndale Board, or Beagle Bone Black, and then "add things" to it via USB, ethernet, MIPI, or even serial and GPIO to build up the complete system. And then make a cool case for it of course =) This is much less likely to go wrong (you are using a pile of existing technology which is well tested and well supported), and to be honest - much less expensive. You can get some pretty good development boards which are almost complete home computer systems for under $100; making your own custom PCB can cost more than that by itself as you are not making enough of them to get a low per-unit price.

Hope that helps,
Pete

Thank you Pete. But I want to learn designing knowledge, it's too important for me. I do not want to build any project soon. I have a Discovery board of STMicroelectronics and did some projects with it, But now I wanna learn how can I build my own board. To obtain this knowledge is very important than cost for me!

Thank you James, but how can I learn from a built board? I can learn about designing the software but how can I learn about designing the hardware? My purpose is hardware side, and I wish to learn how can I build my own devices?
If begining from a small and simple computer is to hard, I'll start with something simpler than like building header boards for using of a microcontroller abilities. If I exampled Raspberry PI, It was my goal noting for start(although if a book was founded about how can we build a board like it, it would be great!).

However, I am seeking a way to reaching my goal, I wanna be a hardware designer at least in a family of Arm processors! Nowadays I see many boards that built with Arm processors by many companies that if you do a search on them, you will find them in a garage in china or many other countries.

Are they many intelligent with most of knowledge and experiment or building these boards are easy? This is a serious question that I want to know! Is it possible for me to make a board like them or not? If it is, with what knowledge? How can achieve that knowledge?

Regards

How can you learn from a build board? With great difficulty, I'll grant you that. In that case, start with something small, like an Arduino. No, don't worry, the Arduino Due is based on a Cortex-M. The Arduino Tre should come out soon, and that is based on a Cortex-A8. The advantage to Arduinos is their Open Source side; you can get the full schematics easily. That will give you an idea on how they did it, how to connect the components, etc.

Designing an Arm-based computer is relatively easy. Get the processor, slap on some DDR-II, some peripherals, and there you go. Things are much easier today than they were a few years ago. While designing a system might be easy, optimizing it, and making it a viable solution is much harder. You cite the Raspberry Pi for this, but have a look at the board; it isn't actually all that "complicated". Don't get me wrong, they did a great job, and routing that board must have been a nightmare, but the components on the board are fairly basic; apart from the CPU and GPU, there are very few ICs, a few resistors and a few capacitors. The goal for Raspberry Pi was to make a low-cost board, balancing purchases, reliability and general awesomeness.

So, back to business. If you want to create your own systems, go for it! Don't let anyone tell you it can't be done; that is exactly how I started electronics. The only difference for me is that 6809s and 68000s were DIPs, and the boards were easy to route. I'm not too sue how you would start; SMCs are hard to solder, and honestly I have no idea how a BGA component is soldered. To start "easily", I think the only DIP packages are Cortex-M devices. However, I'm pretty sure I saw a breadboardable Arm7TDMI. It isn't latest gen, but it might be an excellent way to start off, playing with peripherals, before using Cortex-A devices, and creating your own multiple-layer cards.

You've given me a new idea for a book, but this is a huge field; there is probably enough for several books.

My advice is to start off "small"; play with Cortex-M devices on breadboards to start, maybe even an Arm Classic (the Arm7TDMI was an awesome chip, and in ways, it still is). Don't let anyone tell you what you can't do. My career is full of people who told me what I couldn't do, and I did it anyway. I really hope to see your project soon :-)

I hope I can build my board and you write your book(s). Your comprehensive guide was very helpful. I thank you again and I'll ask more question later, when I'll designing my board.
Good lock my teacher, James!

> and honestly I have no idea how a BGA component is soldered.

You need some form a reflow oven (basically heat the whole board until the solder balls which are part of the BGA package melt). There are some quite fun tutorials using an old household kitchen oven or even a toaster for doing this on the web - but I wouldn't recommend cooking food in the thing afterwards =)

My DIY attempts in the past tended to struggle with boards which are double-sided - things on the bottom of the board have a nasty habit of dropping off. Pesky gravity

> My advice is to start off "small"; play with Cortex-M devices on breadboards to start,

Yep - this is the best advice I've seen. Start small, learn the basics, and then make something a bit more complex for your next project, etc. ... but definitely have a go!

If you have a particular Arm SoC in mind it is always worth checking with the manufacturer of that device - they may be able to share some schematics for a reference board based on their parts.

Pete

Can you make web site, where you present your activity on developing AVR board? You can use free site hosting, if you want.