The Automotive Control Program includes a calibration algorithm that is used to automatically generate the PWM values associated with each data row in the calibration file. This calibration process requires user provided coarse combinations that must be gathered before starting the calibration sweeps.

The calibration pre-work consists of determining the coarse combinations that will allow brightness outputs across the entire input dimming range.

Once coarse combinations have been found that adequately cover the entire brightness range of the PGU, the calibration procedure will map the maximum and minimum outputs of these coarse combinations and RGB PWM values to system backlight values, ranging 0 to 65535. These parameter combinations become individual rows in the calibration look up tables, ensuring that for every input backlight value, the PGU will choose the appropriate coarse combination and RGB PWM values to output the desired brightness level. If gaps in brightness output do exist with the entered coarse combinations, adjust the combination parameters accordingly to close the gaps. See Section 5.2 for more information.

These combinations define a brightness LUT for the system at one temperature. Since LED output changes over temperature, the system needs to be characterized across the operating temperature range of the system.