TCS3404, TCS3414

DIGITAL COLOR SENSORS

TAOS137A − APRIL 2011

29

The LUMENOLOGY

r Company

r

r

Copyright

E 2011, TAOS Inc.

www.taosinc.com

APPLICATION INFORMATION: SOFTWARE

A synchronization input (SYNC IN) is supported to precisely start/stop sensor integration and synchronize with

the light source. The TIMING Register (01h) provides two synchronization modes of operation. The first mode

of operation synchronizes the SYNC IN pin for one integration cycle as specified in the Timing Register (01h).

When the rising edge of the signal is detected, the TCS3404/14 begins integration. The second mode

accumulates a specified number of SYNC IN pulses (see Timing Register) in which the minimum pulse width

is 50

μs. A pulse counter is used to count the rising and falling edges of the pulse(s) and precisely integrate the

light level when the SYNC IN pulse is high.

The following pseudo code illustrates a procedure for reading the TCS3404/14 device using the synchronization

feature:

// Synchronize one integration cycle

// See ”Basic Operation” to power−on and start device

// See ”Configuring the Timing Register” to setup environment

Address = 0x39

//Slave addr − also 0x29 or 0x49

Command = 0x81

//Set Command bit and address Timing Register

Data = 0x21

//Sync one 100ms integration period

//External SYNC IN pulse initiates 100ms integration

Sleep (100)

// See ”Basic Operation” to read Data Registers using Byte or Word Protocol

// Synchronize N number of SYNC IN pulses

// See ”Basic Operation” to power−on and start device

// See ”Configuring the Timing Register” to setup environment

Address = 0x39

//Slave addr − also 0x29 or 0x49

Command = 0x81

//Set Command bit and address Timing Register

Data = 0x30

//Integrate one SYNC IN pulse

//External SYNC IN pulse synchronizes integration

// See ”Basic Operation” to read Data Registers using Byte or Word Protocol