The PCB has the following fetaures:
The PCB schematic is available as a downloadable PDF at: http://encat.g3vpx.net/files/encat-schematic.pdf
Note that the AT45DB041E device is not used and so can be omitted ( They cost £1.05 + VAT from Farnell !).
The PCB shown above was designed using Easy-PC software and commercially manufactured.
Every component has a schematic symbol and PCB footprint (copper, drilling, top silk etc).
A component record then combines the schematic and PCB records and maps the pin numbering between them.
The schematic diagram is built using the schematic symbols.
'Forward design changes' then transfers the schematic design to the PCB layout
placing all components in a 'component bin'.
Then, as components are dragged from bin to layout, connections are shown as straight, fine dotted lines.
These are then manually replaced by PCB tracks.
The software prevents the operator from making connections which are illegal according the schematic.
A final integrity check warns of any electrical discrepancies between layout and schematic.
At the time of writing, G3VPX had 50 bare PCBs available for sale at low cost.
.. more can be manufactured at 2-3 weeks notice.
Home fabrication would be possible using double sided construction with wired-through vias.
This would however require a totally new layout, mainly because of the wired vias:
- Wired vias cannot be located underneath surface mounted ICs.
- Wired vias on home brew boards need to be larger to cope with alignment inaccuracies
between the two sides of the board.