The reason we use the full Raspberry Pi is so that a user can easily use it to install CUPs printer drivers to support printers over USB, Network or Wifi (or even bluetooth I guess if they wish). The Retro-Printer module will sell for around £75, so that brings the total outlay to around £100 including the Raspberry Pi. We will not be supplying the Raspberry Pi because of VAT reasons mainly, as we expect many customers to be outside of the EU and even the UK after 2019, and therefore they can buy the Raspberry Pi from their local supplier, or internationally without paying the VAT.Dave wrote:What parts of the Pi do you use? As this is the quintessential embedded use, you might save a lot of production costs and gain a lot more control of the physical box you sell this thing by redesigning your board to accept a Pi 3 compute module then only implementing the ports you're using. This makes the unit smaller, either cheaper or the same price, and more dedicated to that single purpose. I mean, you could literally have a card with just parallel, USB and a solid 3v3 power supply section. Then you could just use any 1A or so USB PSU.
Right now the RPi compute module is quite expensive as it is so new, but in time I expect it to fall nearer to Raspberry Pi Zero prices. That gets you to where you could potentially fit the entire computer in the parallel connector case.
The longer I can avoid having to register for VAT the better as it is just a hell of a lot of paperwork for no benefit to my business nor my customers (well at least until 2019).
If the compute module comes down in price and has the same GPIO as the Raspberry Pi (1, 2 or 3), then users might decide to use this themselves.