4.2 LED Color Table

To obtain the correct optical response from the LEDs, their relative brightness (that is, the current flowing through them) is not varied linearly, but is varied according to a lookup table derived from the CIE chromaticity diagram. This lookup table is stored in the flash memory of the MSP430 MCU and defines the edges of the inner triangle shown in Figure 3-1, which the EVM traces. The standard EVM lookup table contains 252 locations, each of which contains the correct value for the red, green, and blue LED PWM signals.