ISL29125 RGB Color Light Sensor

Arjun ArunasalamVarun Kutirakulam

Vinay RevankarAvi Singh

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Contents1. Overview2. Camera vs. Color Sensor3. Real World Applications4. How we’re using it5. Electrical Characteristics6. Registers7. Protocols and Operations8. Conclusion

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SparkFun RGB Light Sensor (ISL29125)

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Camera vs. Color Sensor- Cameras

- More Versatile - More expensive - Color Profiling

- Color Sensor- Cheaper- Can be calibrated to be more accurate and tune out external light- Generally more reliable (depends on application)

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Applications● Smart phones, PDAs, GPS, tablet PCs, LCD-TVs, digital picture frames,

digital cameras● Industrial/commercial LED lighting color management● Dynamic display color balancing● Printer color enhancement● Industrial Sorting or Matching

5[https://learn.adafruit.com/adafruit-color-sensors/overview]

Use Case - Tron light cycle game- Utilize the RGB data that the color sensor provides- Compare it against the marker color detected - Deduct health points from that vehicle based on

comparison results

6[https://www.topbestalternatives.com/encom-tron/psp/]

[https://www.lifehack.org/articles/featured/10-things-to-do-with-dry-erase-markers.html]

Electrical Characteristics● Sensing Ranges

○ 5.7 mlux to 375 lux○ 0.152 lux to 10,000 lux

● ADC Resolutions○ 12 bits○ 16 bits

● ADC Conversion Time○ Inversely proportional to

the resolution

● I2C Clock○ 500 kHz

● Active IR Compensation

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Spectral Response

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Registers (Configuration and Status)

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Registers (RGB Data)

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Write Transaction

Signals From Receiver

2 bytes of data is written

1 byte for the address of data , 1 byte for data you want to store in register

Example of Write Transaction

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Signals From Receiver

0x01

0 1 00 00

0x02

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Read Transaction

Signals From Receiver

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Read Transaction

0x09 0x00 - 0xFF

Signals From Receiver

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Read and Burst Read Transactions

Signals From Receiver

Signals From Receiver

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Read and Burst Read Transactions

Signals From Receiver

Signals From Receiver

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Read Transaction

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Signals From Receiver

Interrupt FunctionAn interrupt can be generated on INT whenever the value from either the red, green, or blue light sensor crosses either a minimum or maximum threshold.

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When the value crosses one of the two thresholds, the RBGTHF bit in register 0x08 is asserted to HIGH and the INT pin goes LOW.

● User can configure which light sensor (RGB) will generate interrupt, but interrupt can only be configured to one color.

● User can choose to throw an interrupt after threshold is crossed multiple times, not every single instance.

Interrupt Function

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Configuring the interrupt

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Conclusion● More optimal than camera for simple applications

○ Works well in our project

● Uses I2C bus protocol● Has a convenient interrupt function● Straightforward and understandable configurations

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DocumentationData sheet (https://cdn.sparkfun.com/datasheets/Sensors/LightImaging/isl29125.pdf)

Note: All Images taken from datasheet unless otherwise specified

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Any Questions?

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