TCS3404, TCS3414

DIGITAL COLOR SENSORS

TAOS137A − APRIL 2011

31

The LUMENOLOGY

r Company

r

r

Copyright

E 2011, TAOS Inc.

www.taosinc.com

APPLICATION INFORMATION: SOFTWARE

The following example pseudo code illustrates the configuration of an SMB-Alert style interrupt when the light

intensity changes 20% from the current value, and persists for 2.5 seconds:

//Assume Interrupt Source as Channel 1

//Read current light level

Address = 0x39

//Slave address − alternatively 0x29 or 0x49

Command = 0xB0

//Set Command bit and SMBus Word read

ReadWord (Address, Command, DataLow, DataHigh)

Channel1 = (256 * DataHigh) + DataLow

//Calculate upper and lower thresholds

T_Upper = Channel1 + (0.2 * Channel1)

T_Lower = Channel1 − (0.2 * Channel1)

//Write the lower threshold register

Command = 0xA8

//Address lower threshold register, set Word Bit

WriteWord (Address, Command, T_Lower.LoByte, T_Lower.HiByte)

//Write the upper threshold register

Command = 0xAA

//Address upper threshold register, set Word bit

WriteWord (Address, Command, T_Upper.LoByte, T_Upper.HiByte)

//Enable interrupt

Command = 0x82

//Address interrupt register

Data = 0x24

//SMBAlert style, Persist 2.5 seconds

WriteByte(Address, Command, Data)

In order to generate an interrupt on demand during system test or debug, a test mode (INTR = 11) can be used.

The following example illustrates how to generate an interrupt on demand:

// Generate an interrupt

Address = 0x39

//Slave address alternately 0x29 or 0x49

Command = 0x82

//Address Interrupt Control Register

Data = 0x30

//Test interrupt

WriteByte(Address, Command, Data)

//Interrupt line should now be low