man.bsd.lv manual page server

DESCRIPTION

The ad driver provides an interface to the Data Translation A/D converter. This is not a real-time driver, but merely allows the user process to sample the board's channels one at a time. Each minor device selects a different A/D board.

The driver communicates to a user process by means of ioctl(2)s. The AD_CHAN ioctl(2) selects which channel of the board to read. For example,

chan = 5;
ioctl(fd, AD_CHAN, &chan);

selects channel 5. The AD_READ ioctl(2) actually reads the data and returns it to the user process. An example is

ioctl(fd, AD_READ, &data);