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The GY-31 is a breakout-module name commonly associated with the TCS3200/TCS230 color sensor. It converts light intensity into a frequency signal that a microcontroller can measure; using it to identify colors requires selecting filtered photodiodes and calibrating readings for your particular lighting and setup.
What the GY-31 color sensor does
The TCS3200 uses an 8 × 8 photodiode array and a current-to-frequency converter. Its OUT pin produces a 50% duty-cycle square wave, with frequency proportional to the light intensity reaching the sensor. The chip selects different photodiode sets through control inputs, allowing a controller to read filtered light channels rather than receive a finished color name.
GY-31 is a module name, not a guarantee that every board has identical components or pin placement. Check the specific board’s markings and documentation before wiring. The ams OSRAM product page lists the TCS3200 as discontinued; that is the chip’s lifecycle status, not confirmation that any particular finished module listing is in stock or authentic.
Identify the pins and check compatibility
On documented TCS3200 boards, S0 and S1 control output-frequency scaling, while S2 and S3 select the photodiode type. OUT carries the frequency signal. Some module documentation also includes OE, an output-enable pin, so do not assume a pinout from a different breakout applies to your board.
#1 Best Overall
The TCS3200’s specified supply range is 2.7–5.5 V on the manufacturer’s product page, accessed in 2026. A Kjell module document describes its board as single-supply 2.7–5.5 V and gives a board size of 28.4 × 28.4 mm; the document’s publication date is not stated in its page text. These are specifications for the cited chip and documented module, not a substitute for checking your own board and microcontroller’s supply and logic-level requirements.
Read a GY-31 with an Arduino
An Arduino Project Hub example connects S0–S3 to digital pins and OUT to another digital pin, then selects red, blue, and green photodiode sets in sequence and measures pulse duration. Since pulse duration is the period of the frequency output, it changes with the selected filter and light intensity. The example sets S0 and S1 high for 100% output scaling; its pin assignments and scaling choice are example settings, not universal requirements.
Rank #2
- The GY-31 TCS3200 Color Sensors Module offer precise color recognition with its advanced TCS3200 chip, suitable for projects requiring accurate color detection.
- Featuring 64 photodiodes and clear , this module ensures high accuracy by minimizing light interferences and providing a wide output frequency from 2Hz to 50kHz.
- for electronic engineers, robotics developers, educators, and enthusiasts color detection capabilities in their projects.
- Suitable for use in educational experiments, robotics applications, and any project where precise color identification is essential, with a best detection distance of 10mm.
- Equipped with programmable pin and bright white LEDs for performances in various lighting conditions.
- Confirm the board: identify the chip and the actual S0, S1, S2, S3, OUT, and, if present, OE labels from the board documentation.
- Wire the module: connect power and ground within the documented board’s limits, connect the control pins to Arduino digital outputs, and connect OUT to a digital input. Use logic levels compatible with both devices.
- Configure the controls: set S0 and S1 to the desired output scaling. Set S2 and S3 to select each channel according to the module’s truth table.
- Measure each channel: select a filter, measure the OUT pulse period or frequency, then repeat for the other filters. Keep the sensor’s illumination, distance, and target position consistent while comparing readings.
- Calibrate before classifying: collect readings for the colors you need to distinguish in the actual setup, then tune thresholds against those samples. The project example uses threshold-based classification and notes that one green decision was tricky, so its thresholds should not be treated as universal.
The Arduino example demonstrates reading channels and reproducing a detected color with an RGB LED. It does not establish a general accuracy figure; results depend on illumination, distance, target, module, and setup.
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Where the module can be useful
Examples listed by DFRobot include test-strip reading, color sorting, ambient-light sensing, calibration, and color matching. These are plausible hobby or educational applications, not validated performance guarantees. The Arduino Project Hub example also demonstrates channel reading and RGB LED output.
Rank #3
- 5PCS GY-31 TCS230 TCS3200 Color Sensor Module Color Recognition Sensor Module
How to compare it with another color sensor
There are no controlled head-to-head performance results in the cited material, so it does not support declaring the GY-31 more accurate or easier to use than another model. Compare the practical requirements instead:
- Interface: check whether the output format and control method suit your microcontroller and software.
- Electrical compatibility: compare supply limits and logic levels for both the module and host board.
- Optics and lighting: account for illumination, sensor-to-target distance, and the way the target is positioned.
- Calibration: determine how readings will be sampled and thresholds adjusted for the colors and conditions that matter.
- Lifecycle and availability: distinguish the chip’s discontinued status from the availability and details of individual breakout boards.
What to check when choosing a module
For a GY-31 TCS3200 color sensor module, inspect the listing for the chip marking, S0–S3 and OUT labels, board layout, supply details, and wiring information. If you do not already have an Arduino-compatible controller, the cited example uses an Arduino Uno. A breadboard and jumper wires can support prototyping, but they are not established as mandatory accessories or as items always excluded from module kits.
Quick Recap
Best Value
- Can detect non-luminous object color
- Best detection distance 1cm
Rank #4
- can be connected directly with Microcontroller
- Static detection of the measured object color
- Use bright white LED lights
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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