GP2Y0A21YK0F IR Distance Sensor (2Y0A21)

🔹 Sharp GP2Y0A21YK0F IR Distance Sensor (2Y0A21)

A highly reliable, short to medium-range analog distance measuring sensor from Sharp. It uses a focused infrared beam and a position-sensitive detector (PSD) to output a voltage inversely proportional to the distance to an object. Ideal for non-contact ranging, obstacle detection, and presence sensing.

✅ Specifications:

• Model: GP2Y0A21YK0F (Commonly known as 2Y0A21)

• Type: Analog Output, Infrared (IR) Proximity / Distance Sensor

• Operating Voltage: 4.5V to 5.5V DC

• Average Current Consumption: ~33mA

• Measuring Distance Range: 10 cm to 80 cm (4″ to 31.5″)

• Output Type: Analog Voltage (Non-linear)

• Output Voltage vs. Distance: ~2.1V at 10cm, ~0.4V at 80cm (Inversely proportional)

• Update Period (Cycle Time): ~38.3ms ± 9.6ms

• Dimensions: Approx. 40mm x 16mm x 16mm (L x W x H, including housing)

• Beam Pattern: Narrow, focused cone.

⚙️ Key Features:

• Analog Interface: Simple to read with any microcontroller’s ADC pin (e.g., Arduino, Raspberry Pi with ADC).

• PSD Technology: Less susceptible to ambient light and object color/reflectance compared to simple IR LED/phototransistor pairs.

• Compact & Integrated: Contains all necessary optics, IR emitter, and signal processing circuitry in a single, rugged housing.

• Standard 3-Pin Connection: Power (VCC), Ground (GND), Output (Vout).

📦 Typical Applications:

• Robotics & Automation: Obstacle avoidance, wall following, and collision detection for robots and AGVs.

• Liquid Level Sensing: Non-contact measurement in tanks or reservoirs.

• Object Detection & Proximity Sensing: For vending machines, interactive displays, and safety systems.

• DIY & Maker Projects: Arduino and Raspberry Pi-based distance meters, interactive art, and smart devices.

• Industrial Applications: Simple positioning, edge detection, and material presence sensing.

🔧 Connection & Usage Guide:

1. Wiring (3-pin):

   • Red Wire: VCC (+5V)

   • Black Wire: GND (0V)

   • Yellow/White Wire: Vout (Analog Output)

2. Microcontroller Interface: Connect Vout to an Analog Input pin (e.g., Arduino A0).

3. Reading & Calibration: The output is non-linear. For best results, use a lookup table or the inverse function provided in the datasheet to convert ADC readings to distance in cm.

4. Smoothing: Implement simple averaging or filtering in code to reduce noise in readings.

⚠️ Important Considerations:

• Non-Linear Output: Distance is not a simple linear function of voltage. Calibration/correction is required for accurate measurement.

• Object Properties: Works best on flat, matte, light-colored objects. Dark, shiny, or irregular surfaces can reduce accuracy and range.

• Ambient IR Light: While resistant, very bright sunlight or other strong IR sources can interfere.

• Minimum Distance: Cannot measure closer than 10cm. Objects closer than this may give erratic readings.