30 Jun
2012
30 Jun
'12
12:01 p.m.
2) I
understnad the's some kind of GPIO/user port. How many lines, are
they individually selectable for direction? Can this be easilly used from
C (I assuem there's a C vompiler included with the OS).
There is a 26-pin GPIO port available of which 17 pins can be used for I/O (the rest are power, ground or NC). The GPIO
pins are the
standard bidirectional, tristatable things you would expect. Some
of the in functions are muxed with SPI, UART, I2C and I2S so that
you can use more advanced devices without bit-banging. Almost all
How many (if any) of those clash? In otehr weords can I use the UART and
the I2C (say) at the same time, or do they share port pins?
of these are accessible through standard Linux APIs,
though the
support is not 100% there in all of the distributions currently
extant for the device (they're catching up fast, though).
This page gives a good overview:
http://elinux.org/Rpi_Low-level_peripherals
There's no buffering, and everything is 3.3v, so for a lot of real
world applications you'd need to at least give it some buffers to
keep the ESD demons away. For a lot, though, you can get away
with taking chances (especially for a $25/$35 board).
No, as you know,m I'd buffer them. Ys, the set of buffers, the PCB to put
them on, etc migth well cost more than an Rpi board. But I keep buffers i
nthe junk box. Get Rpi's seems to be non-trivial
-tony