Quote from hippy on September 11, 2011, 17:08
I'm very interested in interfacing to the GPIO and I'd be most keen on 'KISS' and 'cheap and cheerful', just a break-out board which makes it easier to connect to the R-Pi, something nicer than ribbon cable and fanned-out wires
I'm not sure about buffering or level-shifting but I likely would not need or want it. I don't know what voltage the GPIO operate at but would guess 3V3. That's probably good enough to drive 5V logic and micros and putting 5V in should likely work with just a suitable current limiting resistor if they aren't 5V tolerant to start with - Do the hardware guys and gals have a spec of the GPIO electronics ?
From R-Pi Wiki http://elinux.org/RaspberryPiB.....re_Details
There are approximately 16 spare GPIOs, which are brought out to 1.27mm pin-strip. Voltage levels are 3v3. The connector choice is deliberately annoying to connect to directly; there is no over-voltage protection on the board so the intention is that people interested in serious interfacing will use an external board with buffers, level conversion and analog I/O rather than soldering directly onto the main board.
We also bring 2x I2C (3v3), I2S and an SPI (3v3) interface out to the same connector. We support one slave interface for I2C and one for SPI.
I want this board for prototyping to give an easy and quick interface for breadboard or strip board and I don't wan to be constantly soldering onto the headers. I also want to protect my and others from accidental damage, so the chips on the board may blow but the R-Pi will be safe.
This board is quickly becoming a lot simpler then initially planned which can only be a good thing. Other boards with extra stuff could either plug into this board or directly to the R-Pi.
I am now imagining a simple board with a header/ribbon cable that connects to the header on the R-Pi. These signals along with the power and ground taken out with the signal pins running though DIP buffers to another header that’s easier to hookup to the proto board.
As for paying £11 pounds for blank boards this seems a huge amount, I could etch them at home for less and I would be willing to wait for a batch processed ones if I'm ordering lots.