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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