A Curtain Opener

Overview

This repository is about a smart curtain opener and includes various components like a clock, environmental sensors, servo motor control, and more, all integrated with an UNO R3 and an ESP32.

Components

1. Clock

• Timing: 0:00 - 23:59
• Features:
  • timer1 for precise timing.
  • Integration with ESP32 for network time synchronization (TBD).

2. Environmental Sensor

• Functionality: Continuously monitors and compares environmental data against set thresholds.
• Sensors:
  • Temperature & Humidity:
    • Input: D2 (PD2)
  • Photoresistor:
    • Type: ADC
    • Input: A0 (PC0)

3. Servo Motor Control

• Mode: Timer0 phase-correct mode
• Output: PD6

4. Fan/Air Conditioner Control

• Controls DC motor for fan/air conditioner operations.

• DC motor

  • '+' : PD3
  • '-' : GND

5. Communication with ESP32

• Details of communication protocols and methods with ESP32.

5.1 UART

• Mode: 2 stop bits, 8 data bits, no parity bits

• Atmega Pin:

  • TX - TX
  • RX - RX
  • GND - GND

• ESP32 Pin:

  • TX - GPIO 7
  • RX - GPIO 8
  • GND - GND

5.2 SPI

• Master: Atmega 328P

• Atmega Pin:

  • SCK - 13
  • MISO - 12
  • MOSI - 11
  • CS / SS - 10

• Slave: ESP32 (use ESP32SPISLAVE library)

• ESP32 Pin:

  • SCK - GPIO 5
  • MISO - GPIO 21
  • MOSI - GPIO 19
  • CS / SS - GPIO 33

6. ESP32 & Blynk Integration

• Integration details with Blynk app for remote monitoring and control.

Self-Designed Communication Protocol

After a series of designs and tests, we found out that Atmega328P can only receive 4 Bytes of data at once under interrupt mode. eg, buffer[4]

Beacause of time constrain, we do not have enough time to do more test, as a result, we need to embrace this fact. That means we need to use only 4 byte of data to create a very short and efficient communication protocol.

Protocol Structure

• Buffer Size: 4 Bytes (buffer[4])
• Buffer Composition:
  • buffer[0]: Instruction Identifier
  • buffer[1]: Data Byte 1 (if needed)
  • buffer[2]: Data Byte 2 (if needed)
  • buffer[3]: Ending Identifier

Instructions Set (13 Total)

1. A: Open curtain
2. B: Close curtain
3. C: Toggle air-conditioner
4. D: Not used
5. E: Set time to open curtain
6. F: Set time to close curtain
7. G: Set temperature to open air-conditioner
8. H: Set temperature to close air-conditioner
9. I: Set current time
10. J: Smart decision switch for curtain
11. K: Smart decision switch for air-conditioner
12. X: Current time
13. Y: Current temperature and humidity
14. Z: Not Used

Instruction Categories

• On/Off Signal Instructions (A, B, C, J, K): Do not require additional data.
• Temperature and Humidity Instructions (G, H, Y):
  • buffer[2]: Humidity data (int to char + 32 for visibility)
  • buffer[3]: Temperature data (int to char + 32 for visibility)
• Time Transmit Instructions (E, F, I, X):
  • buffer[2]: Hour data (int to char + 32 for visibility)
  • buffer[3]: Minute data (int to char + 32 for visibility)

Data Representation

• Data in int format is converted to char + 32. This is for debugging purposes, as ASCII codes become visible starting from 32.