int opto_read_reg ( int fd; opto_reg_t* ri ); |
Returns the contents of the specified device register. This function should be used with care, as reading a device register can alter the device state and therefore make the device unusable. Be sure to know what you are doing before calling this.
This function accepts the following parameters:
On success, the function will return 0. On failure, it will return a non-null value, which is one of standard error codes.