TCS3472

COLOR LIGHT-TO-DIGITAL CONVERTER

with IR FILTER

TAOS135 − AUGUST 2012

9

The LUMENOLOGY

r Company

r

r

Copyright

E 2012, TAOS Inc.

www.taosinc.com

Interrupts

The interrupt feature simplifies and improves system efficiency by eliminating the need to poll the sensor for

light intensity values outside of a user-defined range. While the interrupt function is always enabled and its

status is available in the status register (0x13), the output of the interrupt state can be enabled using the RGBC

interrupt enable (AIEN) field in the enable register (0x00).

Two 16-bit interrupt threshold registers allow the user to set limits below and above a desired light level. An

interrupt can be generated when the Clear data (CDATA) is less than the Clear interrupt low threshold (AILTx)

or is greater than the Clear interrupt high threshold (AIHTx).

It is important to note that the thresholds are evaluated in sequence, first the low threshold, then the high

threshold. As a result, if the low threshold is set above the high threshold, the high threshold is ignored and only

the low threshold is evaluated.

To further control when an interrupt occurs, the device provides a persistence filter. The persistence filter allows

the user to specify the number of consecutive out-of-range Clear occurrences before an interrupt is generated.

The persistence filter register (0x0C) allows the user to set the Clear persistence filter (APERS) value. See the

persistence filter register for details on the persistence filter value. Once the persistence filter generates an

interrupt, it will continue until a special function interrupt clear command is received (see command register).

Clear

ADC

Clear

Data

Clear

Upper Limit

Lower Limit

AIHTH(r0x 07), AIHTL(r0x 06)

Clear Persistence

AILTH(r 0x05), AILTL(r0x 04)

APERS(r 0x0C, b3:0)

Figure 8. Programmable Interrupt