jamesh wrote:Note that smaller = more expensive.
The Pi is the size it is because of cost. Make it smaller and the components cost more, and are 'harder' to place, which costs more. The Pi size is at the crossover point of smaller = cheaper (less materials) and smaller = more expensive (more costly materials)
Connectors are also a problem at smaller form factors. uHDMI = expensive (and rare), uSD card sockets fragile, are there even standardised uEthernet connectors? uUSB host doesn't exist (or does it? I've never seen one).
So don't expect a smaller one.
I don't want to tell you you are wrong, because most humans dislike being told they are wrong and then take dislike to those that suggest such things, often jumping up and down crying and causing harm to the general situation.
You are absolutely correct jamesh smaller is always more expensive.
Most of the cost of mass produced things is development, and developing smaller things can be more expensive, but once all the mistake and bugs and errors of precision are worked out small things are vastly more expensive because you get a much much higher error rate. I heard that when they make microchips on a silicon wafer the smaller the die size the lower the yeild because there are alway imperfections in the cry stall and because the chips are small there are more likely to be crystall impersections that are in a small part of the chip which ruins the whole chip. I have no idea about this as I am not a chip designer but it is an example someone told me.
Also searching ebay for micro hdmi to hdmi cables I find they are vastly more expensive, some costing as much as £0.99 including shipping from china. Micro usb to usb female adaptor cables are astronomical prices some as much as £1.15 including shipping from china. Yes there is actually no such thing as a micro rj45, but I was thinking to actually create a new standard (identical to the RJ45 width length and pin wise, but about 1/3rd the height). all those connectors should be within 3.3mm height?
I don't know how much the circuit board costs as a percentage of the rpi, but if you could dispense with it would it not be better if you could just stack chips together and know that there was a standard that allowed everything to work together with some fpga type on chip signal routing?
Also this could alllow multiple sandwiches of processor/memory/processor/memory as required?
I know this is way beyond anything the foundation could do but there are some real propeller heads at the foundation that I imagine also have some sway with broadcom and other chip manufacturers.
Would it be worthwhile as an industry standardisation project.
Design spec. package on package standard 25mmx25mmx3.3mm or 25x25x1.65mm electronic package 200 connections top and bottom of package, gnd plane bottom supply voltage top, one side for thermal heat sink, three sides for peripheral interfaces, certain pin orientation to prevent incorrect stacking, could be multiple thin flexible circuit board layers sandwiched onto the package before the pins are fired through. Outer pin array pitch at 2.54mm to allow easy interface for hackers with header pin connections.
I can definitely visualise it in my mind, though maybe explaining is not possible, as I am sure there would be unseen problems with such a design, it does seem vastly more expensive to develop it, as all sorts factors I have no idea of need to be taken into account.
Anyway maybe more expense is worthwhile sacrifice for a smaller form factor?
I am sure eventually entire PC systems will be etched onto the silicon of a contact lens powered by the chemicals produced by our basal tears, but maybe a chip stacking system is the next step forward?
Who wants to pay for it?