Using KiCad for PCB creation
From time to time I like to browse eBay for obscure development boards, Just to see what is available. But I really have to credit a mate of mine for this find. As if it were not for him I would not have found this one. As few months back he asked me if I wanted to buy, a “Verdex Pro XM4-BT” made by Gumstix. This board is very interesting as it is home to and Intel XScale PXA270 at 400Mhz. 64MB of mobile SDRAM, 16MB of NOR flash which houses uboot and a bluetooth radio.
The only issue with this board is that is doesn’t have any out put or input, the only four connectors it has is one 80 pin Hirose DF12(3.0)-80DS-0.5V(86) connector, one 60 pin Hirose DF12A(3.0)-30DS-0.5V(81), a UFL connector for an antenna and a SD card slot. So upon further inspection the 60 pin hirose connector has serial on it, so the idea came to me that I should make a board to break out the serial to a connector so that I can use the linux on the board.
So at this point your probably wondering how I am going to create this breakout board for the verdex. As most cad software costs a fair sum of money, I am going to have to choose open source software.
Upon doing some research the best option for this was KiCad, as it has a fair bit of support. I set out to learn how to use KiCad by jumping in and starting designing as well as by feel and a lot of googling “how to’s”.
The first thing I went ahead and did was creating a schematic, as this is the logical layout of the PCB. The schematic layout part of KiCad is very good and is easy to use. All your tools are on the right of the screen, and you just click to place a part.
In about a night or two I had down packed the schematic layout, and it looked like so:
So with the schematic complete, I moved on to the physical layout of the board.
Touching up and Build of materials
I thought that I had everything ready to go to create a physical layout. But little did I know that I forgot to assign each part in the schematic a footprint. As I was completing this task I decided to also build. A Build of materials sheet or what is called a BOM. I did this now to ensure that the footprints matched up with parts that I could physically buy.
Then I proceeded to create a physical layout of the board, which KiCad does by generating netlist file with all the footprints and then reading it back in to the board viewer.
Creating the physical layout
Now that the logical layout has been set out, it is time to create the physical layout. To do this we generate a netlist of our logical layout, which is done by clicking the net button in the tool tool bar.
This creates a netlist file now we read this in using the PCBnew button in KiCad. Then selecting the net button, which looks the same as the one in the logical layout. Upon first read in everything is layed out over the top of each other like so.
So after a little bit of fiddling around, I managed to move parts around to create a simple layout.
But found it was a little cramped, so I decided to make the board boundaries the size of the verdex itself which ended up looking like this.
After even more fiddling around I managed to create two ground planes, route out all the tracks and add some vias. This all these things complete the finall product looked like this.
So while I managed to create a PCB from start to finish with some help from a mate, and googling my way to victory. I would still say I have a lot to learn in terms of the electrical engineering side of things. I will link in my files on this site when I am done on a git lab setup when I am ready. And will also link in some reference links as well.