Thursday, November 19, 2015

Homemade ARM Board Running Linux with LCD ,Part 3: PCB Assembly and First Boot

 this is third part in the series of making a linux capable ARM processor board at home, last part we have designed schematic and PCB , in this part we are going to assemble PCB and  see if it boot for first time. here is Second Parthere is First part and Part 4 U-boot Bootloader Porting and Cross Compile.

there are very few challenging part which may create  a little issue in soldering. but all the part are hand solder-able with  a little or no extra tool. i have a hakko fx-888 soldering iron with standard tip , kester  flux  , paste and thin kester solder wire.i also have  a cheap Chinese hot air and an descent quality toaster oven. although hot air is all we need.

i have ordered PCB from osh park , they came very fast and good quality. as usual i have received 3 boards ,  i have also ordered stencil from osh stencil. stencil is not actually needed , it only help to solder all the component faster . if you don't want stencil you can always do without it , new BGA always comes pre balled so no stencil needed ,Processor has leads so no problem at all.  
the component which need a little care while soldering are

Friday, November 6, 2015

Homemade ARM Board Running Linux with LCD ,Part 2 : Schematic and PCB Design

            this is second part in the series of making a ARM linux Board at home, in last part we have decided what we need and why. now we are going to build schematic for our board. as we are using Allwinner A13 CPU , we need it's datasheet and other reference manuals.although there is only a limited amount of data available direct from manufacturer,but there is pleanty of data there from other source , sunxi website is good place to start. all the reference docs i have used are available in my github

I have found this datasheet for our CPU.As A13 is quite common processor in cheap Chinese tablets, and olimex also has few boards with same CPU. there is tons of reference material available online.

Thursday, November 5, 2015

Homemade ARM Board Running Linux with LCD ,Part1:Requirement Definition

         After quite lot of  research through various online document and article and working with many different things, i have finally managed to get my first Linux capable ARM Cortex-A8 board up and running. making the board i hae faced many  different kind of difficulties with different section. the board is Based to a ARM Cortex-A8 CPU running at 1Ghz which is really quite lot for homemade hand assembled stuff. i will take you with me on a journey how you can approach to come up with your custom linux board.

it is going to be some what descriptive tutorial with almost every aspect covered. so i have divided the whole things into parts. next part follows the previous.

how to decide what embedded Processor you Need?
Requirement Definition, first of all you need to determine what are your requirement and is this possible to fulfil them with  some high speed microcontroller with on chip RAM etc. or we need some high speed processor ?  As going for very high speed processor may often lead to have a large amount of extra hardware like you may need many power rails , external RAM,external Flash/ROM etc. which ultimately goes with expensive development and expensive final product.