Grove TCS34725 with ESP32: RGB Color Sensor Guide

Read red, green, blue and clear-channel measurements from the Grove I2C Color Sensor V2 using an ESP32. Begin with raw counts and controlled lighting before attempting to label an object by color.

Identify the V2 sensor

This guide is for the TCS34725FN-based Grove V2 module. An older Grove color sensor or a TCS3200 frequency-output board uses a different driver and wiring. Check the PCB version and selected product rather than choosing a library solely because its name contains “color”.

Prepare Arduino and the library

Install esp32 by Espressif Systems in Arduino Boards Manager. The C3 examples use ESP32C3 Dev Module with USB CDC On Boot enabled and Serial Monitor at 115200 baud. Start with a working Arduino upload setup, then disconnect power before changing wires.

Install Adafruit TCS34725 and its Adafruit BusIO dependency. The example explicitly uses the TCS34725 class and address 0x29. It does not use the older GroveColorSensor API.

Connect the Grove I2C port

These are GPIO numbers on the ESP32-C3 Supermini, not physical header numbers. Identify the Grove contacts from the module labels; cable color is only an aid. For another ESP32 board select free pins using its pinout and change the code. Keep I2C pull-ups at 3.3 V.

The connection is to the Grove module, not to a bare sensor IC. Leave any interrupt output unused for the first polling example. Start with one sensor on the bus; a second device at 0x29 needs isolation or a multiplexer. See the TCA9548A guide if addresses conflict.

Read RGBC counts

Upload the sketch, open Serial Monitor and move an object in front of the sensor while keeping the distance constant. The final number is the unfiltered clear channel. It helps distinguish a dark scene from weak responses in a specific color channel.

#include <Wire.h>
#include <Adafruit_TCS34725.h>
Adafruit_TCS34725 color(TCS34725_INTEGRATIONTIME_154MS, TCS34725_GAIN_4X);
void setup() {
  Serial.begin(115200); delay(1500);
  Wire.begin(6, 7); Wire.setClock(100000);
  if (!color.begin(TCS34725_ADDRESS, &Wire)) {
    Serial.println("TCS34725 not found. Check VCC, GND, SDA, SCL and version.");
    while (true) delay(1000);
  }
  Serial.println("R,G,B,Clear (raw counts)");
}
void loop() {
  uint16_t r, g, b, clear;
  color.getRawData(&r, &g, &b, &clear);
  Serial.printf("%u,%u,%u,%u\n", r, g, b, clear);
  delay(500);
}

Control light before calibrating color

1. For object measurement use the module illumination as appropriate and keep the object at a repeatable distance. For a light-source test disable the module illumination using its documented switch.
2. Record a dark reference and a white reference under the same geometry.
3. Compare channel ratios and repeatability before defining classification thresholds.
4. If counts approach the conversion limit, reduce gain, shorten integration or reduce the incident light.

The example uses 154 ms integration and 4× gain as a starting configuration. Raw counts are not calibrated screen RGB values or a guarantee of accurate color naming. An object can give different readings under another lamp or at another distance.

Troubleshooting

Software versions and validation

Documentation reviewed on October 21, 2026. The included minimal sketch was compile-checked with Arduino-ESP32 3.3.0; library versions are listed below. Compilation does not replace a test on your physical module.

Adafruit TCS34725 1.4.4, Adafruit BusIO 1.17.4

Downloads and references

• Seeed Grove Color Sensor versions and interface
• Adafruit TCS34725 library and examples
• Espressif Arduino-ESP32 documentation

Download the minimal Arduino sketch (.zip)

Related products

• Grove I2C Color Sensor V2 (TCS34725FN) – RGB Color Sensing