This is a 18 bit 8 channel data acquisition system for Raspberry Pi, based on an AD7609 from Analog devices. This experiment is an attempt to control the device using a parallel interface to achieve it's maximum sample rate of 200k samples/second.
Why the AD7609?
The device was chosen because of its relatively simple interface options, either an SPI interface (Limited to 50 ks/S) or a parallel interface capable of 200ks/S. It has no internal register structure and is a "simple" logical state device. The device has 8 balanced inputs with an input impedance of 1MOhm. If you need unbalanced inputs the AD7608 is an alternative you should look at. It is pin for pin compatible and should function on this PCB without problem. Full details of the AD7609 can be found in the Data sheet.