SWSB - Smart Waste Sorting Bin

An ESP32-based automated waste sorting bin that classifies waste into:

• Biodegradable (paper)
• Non-biodegradable (plastic/metal)

The device exposes a built-in web interface over Wi-Fi Access Point mode, so you can control it directly from a phone or laptop without a router.

What This Project Does

When an item is placed in the bin:

1. The capacitive sensor checks for plastic/metal.
2. The IR sensor checks for paper.
3. The ESP32 decides the category.
4. The matching servo opens the flap.
5. The web dashboard updates the counter.

Current Firmware Behavior

The firmware in IKADUHA.ino includes these fixes:

• Auto mode now triggers only when a sensor detects an item.
• Empty-bin sorting is prevented in classifyAndSort().
• Wi-Fi runs in Access Point mode (WiFi.softAP) for offline demos.
• Servo movement helper formatting/structure is clean and consistent.

Bugs and Errors Found (Fixed)

The original firmware had four issues. These are now fixed in IKADUHA.ino.

#	Type	Original line(s) in old code	Issue	Impact	Fix
1	Bug (Critical)	IKADUHA.ino:145	Auto mode condition was always true	Bin kept sorting even when empty	Removed always-true branch from condition
2	Bug (High)	IKADUHA.ino:168-172	Fallback path sorted as plastic when no sensor detected item	False plastic count and unnecessary servo movement	Return early when no item is detected
3	Error (High)	IKADUHA.ino:6-7, IKADUHA.ino:86-100	Wi-Fi used WiFi.begin() (router dependency)	Web UI unavailable without matching external router	Switched to WiFi.softAP()
4	Error (Low)	IKADUHA.ino:179	slowMoveServo() indentation/style inconsistency	Harder to maintain and review safely	Cleaned structure and indentation

Bug 1 (Auto mode always triggered)

Original location in old code: IKADUHA.ino:145

Original:

if (capVal == LOW || irVal == 0 || (capVal == HIGH && irVal == 1)) {

Fixed:

if (capVal == LOW || irVal == 0) {

Bug 2 (Sorted with empty bin)

Original location in old code: IKADUHA.ino:168-172

Original:

} else {
    Serial.println("Plastic detected (fallback) -> Servo2 (right)");
    sortPlastic();
    nonBioCount++;
}

Fixed:

} else {
    Serial.println("No item detected, skipping.");
    return;
}

Bug 3 (Router-dependent Wi-Fi setup)

Original location in old code: IKADUHA.ino:6-7, IKADUHA.ino:86-100

Original:

WiFi.begin(ssid, password);

Fixed:

WiFi.softAP(ssid, password);

Error 4 (Indentation issue in slowMoveServo())

Original location in old code: IKADUHA.ino:179

Original:

if (currentAngle < targetAngle) {
for (int pos = currentAngle; pos <= targetAngle; pos++) {

Fixed:

if (currentAngle < targetAngle) {
    for (int pos = currentAngle; pos <= targetAngle; pos++) {

Pin Mapping

Function	ESP32 Pin	Notes
Capacitive sensor output	GPIO 21	Detects plastic/metal
IR sensor output	GPIO 19	Detects paper
Manual push button	GPIO 4	Active LOW, INPUT_PULLUP
Servo 1 (left flap)	GPIO 13	Paper bin
Servo 2 (right flap)	GPIO 14	Plastic bin

Hardware Requirements

• 1x ESP32 development board (example: DevKit V1)
• 2x SG90 servo motors (or equivalent)
• 1x Capacitive sensor (digital output)
• 1x IR obstacle sensor (digital output)
• 1x Push button (optional)
• Jumper wires
• External 5V power supply for servos
• USB cable for programming

Important Power Note

Do not power servos from the ESP32 3.3V pin.

Use a separate 5V supply for servos and make sure grounds are common:

• Servo PSU GND <-> ESP32 GND
• Sensor GND <-> ESP32 GND

Software Setup

1. Install Arduino IDE:
   • https://www.arduino.cc/en/software
2. Add ESP32 boards package:
   • File > Preferences > Additional Board Manager URLs
   • Add: https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
3. Install board package:
   • Tools > Board > Board Manager
   • Install esp32 by Espressif Systems
4. Install ESP32Servo library:
   • Option A: Copy pr/ESP32Servo to your Arduino libraries folder.
   • Option B: Sketch > Include Library > Add .ZIP Library and select the folder/zip.
5. Open IKADUHA.ino.
6. Select board and port:
   • Board: ESP32 Dev Module
   • Port: your ESP32 COM port
7. Upload firmware.
   • If upload stalls at Connecting..., hold BOOT until flashing starts.

Wi-Fi and Web Interface

After boot, connect your device to:

• SSID: SmartBin
• Password: smartbin123

Then open:

• http://192.168.4.1

Available controls:

• Automatic Mode: sorts automatically when sensors detect an item
• Manual Mode: disables automatic sorting
• Sort Item: one-time sort trigger
• Reset Counters: resets paper/plastic counters

Sensor Decision Logic

• capVal == LOW -> plastic/metal -> Servo 2 (right flap)
• irVal == 0 -> paper -> Servo 1 (left flap)
• no detection -> no action

Servo Calibration

Adjust these values in IKADUHA.ino based on your physical build:

int servo1Home = 0;
int servo1Left = 90;
int servo2Home = 90;
int servo2Right = 180;

If motion is too fast/slow, tune:

int stepDelay = 10; // ms per degree

Troubleshooting

• Servos not moving:
  • Recheck signal pins (GPIO 13, GPIO 14) and external 5V supply.
• ESP32 resets/twitching servos:
  • Usually power instability. Use separate servo power and common ground.
• SmartBin network not visible:
  • Confirm firmware upload succeeded and reset ESP32.
• Web page not loading:
  • Ensure device is connected to SmartBin, then open http://192.168.4.1.
• Wrong bin opens:
  • Verify sensor placement and pin wiring.
• Upload fails:
  • Hold BOOT during upload and use a data-capable USB cable.

Project Structure

SWSB/
|- IKADUHA.ino
|- README.md
|- SETUP_GUIDE.txt
`- pr/
   |- ESP32Servo/
   `- sketch_oct17a/

Notes

• SETUP_GUIDE.txt includes extra setup-oriented notes.