Abstract: An improved IR occupant position detection system that provides accurate and reliable classification and position information at a speed sufficient to timely inhibit or otherwise control deployment of occupant restraints. A two-dimensional array of IR emitters is selectively activated to periodically illuminate two or more of predetermined viewing planes in the vicinity of a passenger seating area, and the reflected IR energy is detected by a photo-sensitive receiver and analyzed to detect the presence of an occupant, to classify the occupant, and to identify and dynamically track the position of the occupant's head/torso relative to predefined zones of the passenger compartment. Modulating the intensity of the emitted IR beams with a known carrier frequency, band-pass filtering the received signal, and synchronously detecting the filtered signal distinguishes the reflected IR energy from other signals picked up by the IR receiver.

Abstract: In a first controller that runs a first control algorithm and a first interrupt service, wherein the first control algorithm includes a first series of commands repeatedly executed in sequence, wherein the first interrupt service performs a second series of commands when the first interrupt service is triggered, wherein the first controller includes a first free running counter with a counter timer value that repeatedly increments and resets when the counter timer overflows, a data communication method comprising the steps of: in each sequential execution of the first series of commands: reading a data signal to be transmitted; responsive to the data signal, computing an on-time; setting a first edge of a serial transmission signal; and loading a register with a value equal to a sum of the first counter value and the on time; independent of the first series of commands: comparing the first counter value to the register value; when the first counter value equals the register value, triggering the first interru