The schematic is 100% complete at this point. The only changes were to add part numbers into the schematic so a BOM (bill of materials) could be generated. I then took the BOM and created 1008.mod.ods. It is an Open Office calc spreadsheet (open office excel equivalent) which uses the correct prices for the quantities needed for this project. (My standard tool uses quantity 100 for each part, but this project uses far less). If you find a group of friends that need a couple display completely swapped out, it would be much cheaper than this. The most expensive part is the LCDs which the project requires 28 and we are playing $1.57 each, but if you could buy 100, they would be down to $1.25 each.
The BOM cost ends up being $142.58. The only thing that isn’t in that cost is shipping from mouser which is around $5 to $7. I also included solder paste to make the boards in that BOM cost because I assumed that somebody making this would not have that lying around. I use Chip Quik which seems to work out nicely. You could hand solder this but hand soldering the 600 pins of the NFETs would be really really painful. That in itself is worth the $17 for the solder paste.
To get the PCB price that I quoted, use ITeadStudio and choose a 5×20 cm set of boards. It is under open PCB->PCB prototyping category. Choose larger than 10×10 cm and when you are choosing the options, 5×20 cm is an additional cost of $7. The cheapest shipping used to take about 4 weeks, but they just switched from Hong Kong post, so I’m not sure how long this is going to take.
This is equivalent of the pinscore replacement system. It includes a potentiometer for dimming the displays. If you don’t need to buy the setup materials, i.e. the solder paste, the project should come in around $120. The pinscore displays go for $200, so truth be told, this is not a whole lot of savings. This is also why I won’t be manufacturing these in any quantity. Pinscore has the benefit of buying parts in higher quantities that individual hobbyists can’t necessarily match.
Next post on this topic won’t be until we receive the boards. I think that I need to go back to working on Disaster.