Source: https://mokxi.com/libraries/adafruit-tcs34725 Updated: 2026-11-11 Libraries / Sensors Arduino library · Sensors # Adafruit TCS34725: red, green, blue and clear counts The TCS34725 is an RGB color sensor with a fourth, unfiltered clear channel, usually sold on a breakout with a white LED beside it to light whatever it is pointed at. Adafruit’s library talks to it at 0x29 and returns four 16-bit counts per reading. Open the example in the editor See the calls Built in on Mokxi: #include and it builds, with nothing to install. Free, and no account needed. ## What Adafruit TCS34725 does Two settings decide what those counts mean. The integration time, from 2.4 ms to around 700 ms, is how long the chip gathers light before it reports, and the gain multiplies the result by 1, 4, 16 or 60. A short time and low gain suit a bright scene; a dark object needs more of both. Push too far and the counts pin at the top, so keep an eye on the clear channel. Raw counts depend on how bright the light is as much as on the color. Sorting projects divide each of red, green and blue by their total, which gives shares that hold steady as brightness changes, and compare those with a table of known colors. The color sorter below does exactly that before swinging its servo to a bin. calculateLux() and calculateColorTemperature_dn40() turn the same counts into lux and kelvin, and the clear-channel interrupt with its persistence is simulated as well. Library Manager name | Adafruit TCS34725 Author | Adafruit Include | #include Boards | every board Mokxi compiles for but ATtiny85 In the simulator | Simulated: it runs against the part the way it does on the bench. Parts it drives | Color sensor, TCS34725 ## Install it It builds on every board Mokxi compiles for but ATtiny85. In Mokxi it is built in: #include and the sketch compiles, with no download, no zip and no Library Manager. On a real board, install "Adafruit TCS34725" by Adafruit from the Arduino IDE’s Library Manager (Sketch, Include Library, Manage Libraries), or add Adafruit TCS34725 to lib_deps in PlatformIO. Mokxi follows the calls of release 1.4.4, so a sketch written here builds there too. - ESP32-C3 - Arduino Uno - Arduino Nano - Arduino Mega 2560 - Arduino Leonardo - SparkFun Pro Micro - Arduino Micro - ESP32-C6 - WCH CH32V003 - Raspberry Pi Pico - Raspberry Pi Pico W - Seeed XIAO SAMD21 - STM32 - STM32 Nucleo-F411RE - STM32 Blue Pill - micro:bit V2 - Arduino Uno R4 - ESP32 DevKit - ESP32-S3-DevKitC-1 - ESP8266 NodeMCU - Arduino Pro Mini 3.3 V - Seeed XIAO ESP32-C3 - ESP32-C3 SuperMini - Seeed XIAO ESP32-C6 - ESP32-DevKitC V4 - LOLIN32 Lite - Wemos D1 R32 - Cheap Yellow Display - TTGO T-Display - Seeed XIAO ESP32-S3 - Arduino Nano ESP32 - Arduino Nano RP2040 Connect - Seeed XIAO RP2040 - Waveshare RP2040-Zero - Arduino Uno R4 WiFi ## The calls you will use In the order a sketch meets them. ### Adafruit_TCS34725 tcs = Adafruit_TCS34725(TCS34725_INTEGRATIONTIME_50MS, TCS34725_GAIN_4X) Creates the driver with an integration time and a gain. With no arguments it uses 2.4 ms and 1x, which reads close to zero indoors. ### tcs.begin() Reads the ID register, applies the settings and starts the color cycles. Returns false when nothing answers at 0x29. ### tcs.getRawData(&r, &g, &b, &c) The four counts as uint16_t. It then waits one integration time, so a long setting slows loop() by that much. ### tcs.calculateColorTemperature_dn40(r, g, b, c) Correlated color temperature in kelvin from all four counts. calculateColorTemperature(r, g, b) is the older three-count method. ### tcs.calculateLux(r, g, b) An estimate of illuminance in lux worked out from the three color counts. ### tcs.setGain(TCS34725_GAIN_16X) Changes the gain while running; setIntegrationTime(TCS34725_INTEGRATIONTIME_154MS) does the same for the time. Auto-ranging code steps these up or down from the clear count. ### tcs.getRGB(&red, &green, &blue) Each channel as a share of the clear count scaled to 0 to 255, as floats, ready to drive an RGB LED. ### tcs.setInterrupt(true) Enables the clear-channel interrupt. setIntLimits(low, high) sets the window it watches, and clearInterrupt() releases the INT pin after it fires. ## Example: Color sorter On the Arduino Uno R3. It runs in the browser exactly as printed. sketch.ino · Arduino Uno R3 Open it in the editor, wired and ready to run · Color sorter: the project page ## Common errors and how to fix them ### No TCS34725 found ... check your connections begin() saw no reply or the wrong ID at 0x29. Check the bus wiring, and that no other device on the same wires uses 0x29, such as a VL53L0X or VL53L1X distance sensor. ### All four counts read 0 or close to it The default constructor uses 2.4 ms at 1x, far too little for a room. Pass a longer time and more gain, as the sorter does with 50 ms and 4x, and make sure the LED is lit. ### Every object is classified as the same color The counts are probably saturated, typically from the LED at close range with a high gain. Lower the gain or the time until the clear count stays well below 65535, then measure the color table again. ### Colors change when the room lights change Raw counts mix brightness into color. Divide red, green and blue by their sum and compare those shares, with the sensor’s own LED doing the lighting. ## Questions and answers ### What is the clear channel for? It sees all visible light with no color filter, so it measures brightness. The sorter uses a low clear count to tell an empty chute from a candy. ### Which integration time should I start with? The tutorial’s 50 ms at 4x is a fair start under the module’s LED. Lengthen it for dark objects and shorten it if the clear count nears the top. ## Projects that use Adafruit TCS34725 Built-in projects that include it. Each page has the full sketch and opens in the editor, already wired. Holi color catcher Hold anything colorful to a TCS34725 sensor and a strip of eight WS2812B LEDs catches its color, names it on the Serial Monitor and keeps a row of the last eight. ## Keep going ### Learn - Arduino Color Sensor: TCS34725 Candy Sorter - I2C Explained: Addresses, Acknowledges and Pull-Ups ### Parts - Color sensor, TCS34725 ### More sensors libraries - DHT sensor library - DHT20 - VL53L0X - Adafruit_VL53L0X - HX711 Arduino Library - MPU6050 - Adafruit MPU6050 - BME280 Every built-in library · Open the editor ## Try Adafruit TCS34725 without installing anything Open the example, change the sketch, and keep your version in a free account. Start building free Open the editor