Melexis Technologies Nv

Raik Frost

Thomas Freitag

Michael Bender

Jörgen Sturm

A device having a light emitting diode (LED) of a red-green-blue type, a pulse width modulation (PWM) control, a current supply, and a microcontroller. The RGB LED device arranged for setting a PWM duty cycle using the PWM control and for supplying to the LED either a current of a first value or a current of a second value higher than the first value from the current supply. A method for calibrating the LED of the RGB LED device by measuring sets of tristimulus values when the PWM duty cycle and currents are applied, and calculating from the measured tristimulus values parameters to express colour intensity as a function of PWM duty cycle under the applied current. A method for operating the RGB LED device where calibration parameters linked to the use of a current having a low value and calibration parameters linked to the use of a high current value are determined and used to account for a possible working point shift when switching between the two currents. The calibration parameters including the parameters calculated from sets of tristimulus values to express colour intensity as a function of PWM duty cycle for the applied currents.

Method and device for calibrating LED lighting

A method of operating a plurality of driving units for powering electronic units comprises interchanging a data frame including a bit sequence, between a master control unit and at least one of a plurality of driving units at slave nodes. A step of applying an ID field comprises indicating the driving unit address using a first bit sub-string comprising N bits, allowing the master control unit to identify whether data should be received or transmitted, or allowing each addressed driving unit to decode which action is required by the master control unit, using an R/T command bit, performing a length decoding step, for including information in the ID field regarding the type of instructions included in the data frame, using an F function bit, and assigning data bits to different electronic units or indicating in the length of the bit string in the data field, using a second bit sub-string.

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Munich, Georgia

Raik Frost