Before I order any of the PCB’s I also need to consider adjusting the size of the modules. I have ordered several standard project boxes that I will consider using, but I lack exact mechanical dimensions on them. And I have to figure out the mounting holes on the motherboard to the project boxes. The…
The next module I want to make is the motherboard(s). I want to start with a 2, 4 and 8 module Motherboard. An early demo of a 4-module board is shown above. In this case I have mounted 4 x Ethernet modules – an advanced system will usually have two Ethernets for redundancy, but you…
Fisished routing. One days work – first attempt on 4-layer design. I must admit KiCAD did most of the job. Components top without Ethetnet modul. Components bottom layer All layers. I decided to use Ground and Power as the middle layers. I don’t add ground layer on top or bottom since this will be hand-soldiered.…
This prototype have a Wiznet breakout on top and a USB-C on bottom in front. The Wiznet breakout cover the M2 screw holes, so mouting these will be a little tricky, but doable. I will consider pushing the breakout a bit in-I need to alig RJ45 and USB-C infront anyway and that will help.
I have finished schematics, footprints, 3D models and placed the components and this starts to look good. The pictures below are exported directly from KiCAD. The Top layer contains the Ethernet module, MCU, crystals, leds and SWD. Only the 16Mhz crystal and some caps are under the Ethernet module. The bottom contains a USB-C connector,…
I decided to add place for bothy CAN-FD and RS485 as IPC on the module. The design seen from left is CAN at top, RS485 on bottom – switching the module to right we get the oposite. I have the extra space to do it and it allows me to build modules using UART’s only.…
This ends up as a prototype anyway because I lack components to optimize for production. I am using 4 layers this time because I want better isolation between signals. I can mosly route on a single layer, but I had some bad experience with signal integrity on 2 layers. This is the first time I…
KiCAD 6.0.8 is great. Many new improvements. But, also some issues as links to footprints and 3D images are broken. I opened XPortHub2 because I neeeded reference to a coil and found that the RJ45 is missing on the 3D View – easy to fix, but I have seen a few of these. You also…
As I can’t get hold of the components I want and this becomes a prototype that will change I can as well start using both sides of the board. The SOP8 CAN tranceiver get a bit squeezed on the top layer so I can put it at bottom – in which case I can add…
TI have made an excellent series of CAN-FD Tranceivers in SO23-8 format. All the rest is SOP8 and you can compare the two footprints below. The bugger is that I can get SOP8 versions, but I can not get any of the SO23-8 versions. So for now I have to accept added space here as…