Schematic
With this program you can use Maxim's 8 input analog digital converters types MAX1202 MAX1203, with 12 bit resolution and MAX1204 with 10 bit resolution, between the spi_bcm2708's SPI interface on the Raspberry pi.
The ic power supply is 5V, but the SPI interfaces pin could work at different voltages, you can use the 3,3V from P1 Raspberry's port and input it on the VL chip pin, then the SPI logic work at 3,3V and yo haven't any problem interfacing the chip with Raspberry pi.
Tryed with clock speed of 2MHz and below.
Source code from Github
Tested with 2013-09-10-wheezy-raspbian linux.
To enable the SPI interface you must modify the file
/etc/modprobe.d/raspi-blacklist.conf
commenting this line
#blacklist spi-bcm2708
If you want run the program without root privileges you can execute these command
sudo groupadd spi
sudo usermod -a -G spi pi
sudo su
echo 'DEVPATH=="/devices/platform/bcm2708_spi.0/spi_master/spi0/spi0.0/spidev/spidev0.0", GROUP="spi"' > /etc/udev/rules.d/99-spi.rules
echo 'DEVPATH=="/devices/platform/bcm2708_spi.0/spi_master/spi0/spi0.1/spidev/spidev0.1", GROUP="spi"' >> /etc/udev/rules.d/99-spi.rules
reboot
that add the spi group and add to it the pi user.
The last two lines add a udev rule that assign the spi group to the SPI bus.
In that manner you can run the program
./raspandmax
without sudo