🎨 Analog Grayscale Sensor

📌 Description

The analog grayscale sensor detects how much light is reflected from a surface. Dark colors (like black) reflect less light, while bright colors (like white) reflect more. The sensor converts this into an analog value that the microcontroller can read.

🎯 Use

In our projects, the grayscale sensor is used to:

• Detect lines on the floor (line‑following robots).
• Differentiate between light and dark surfaces.
• Measure reflectivity for object detection.

👉 Think of the grayscale sensor as the robot’s eye for shades — it sees how bright or dark something is.

Module parameters

Pin name	Description
G	GND (Power Input Negative)
V	VCC (Power Input Cathode)
S	Analog signal pins

• Supply voltage: 3.3V/5V
• Connection: PH2.0 terminal wire
• Installation method: double screw fixing

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🖥️ Code Explanation

import machine
import time

adc39 = machine.ADC(machine.Pin(39))   # Sensor connected to pin 39

while True:
    print('Grayscale value: ')         # Print label
    print(adc39.read())                # Print sensor reading (0–4095)
    time.sleep_ms(100)                 # Wait 0.1 seconds

Step by Step

1. import machine, time → Tools for pins and timing.
2. adc39 = machine.ADC(machine.Pin(39)) → Pin 39 reads the analog signal from the grayscale sensor.
3. while True: → Loop that repeats forever.
4. print('Grayscale value: ') → Prints a label.
5. print(adc39.read()) → Shows the sensor’s value (0 = dark, 4095 = bright).
6. time.sleep_ms(100) → Adds a short delay between readings.

👉 Together, this program makes the sensor report brightness levels every 0.1 seconds.

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✅ Conclusion of the Test

• If the printed values change when moving the sensor over black, white, or gray surfaces, the program is working correctly.
• This test shows how the robot can read analog input and detect brightness differences.
• Later, the grayscale sensor could be used for line‑following robots, surface detection, or even sorting objects by color shade.