Hardware Components Guide

• Simple Sexy PCB created by Chimpo Forum

This document provides detailed information about each hardware component used in the Chelonian Access system, including current usage and potential capabilities.

Core Components

1. ESP32-C3 SuperMini

Specifications:

• Microcontroller: ESP32-C3 (RISC-V)
• Operating Voltage: 5V (native)
• Clock Speed: 160MHz
• Flash Memory: 4MB
• RAM: 400KB SRAM
• ROM: 384KB
• Digital I/O Pins: 11
• PWM Channels: 11
• Analog Inputs: 6 (A0-A5)
• WiFi: 802.11 b/g/n (2.4 GHz)
• Bluetooth: 5.0 (BLE)
• Size: Ultra-compact 22.52 x 18mm

Current Usage:

• Pin 10: RFID SS (Slave Select)
• Pin 9: Relay 1 (Door unlock)
• Pin 6: Relay 2
• Pin 5: Relay 3
• Pin 4: Relay 4
• Pin 1: JQ6500 TX (to JQ6500 RX)
• Pin 0: JQ6500 RX (from JQ6500 TX)
• MISO/MOSI/SCK: SPI for RFID

Available Features Not Yet Used:

• Pin 8 (Blue LED) - Status indication
• WiFi capabilities for remote access
• Bluetooth LE for mobile app integration
• Deep sleep modes (43μA in deep sleep)
• ADC pins for battery monitoring
• PWM for LED brightness control
• RTC peripheral for timekeeping
• Touch sensor capabilities

Future Potential:

• Over-the-air (OTA) updates
• Web server for configuration
• MQTT integration
• BLE beacon functionality
• ESP-NOW for mesh networking

2. PN532 NFC/RFID Module

Specifications:

• Operating Voltage: 3.3V-5V
• Communication: SPI, I2C, or HSU (High Speed UART)
• Supported Cards: Mifare 1K, 4K, Ultralight, DesFire, and more
• Read Range: 5-7cm typically
• Frequency: 13.56MHz
• Current Consumption: ~150mA peak, ~50mA average

Current Usage:

• SPI communication mode
• Reading Mifare Classic 4-byte and 7-byte UIDs
• Basic card presence detection

Available Features Not Yet Used:

• Card emulation mode
• Peer-to-peer communication
• Writing data to cards
• Reading card memory sectors
• Authentication with card keys
• Anti-collision for multiple cards
• Low power card detection mode

Future Potential:

• Store access levels on the card itself
• Use card memory for logging
• Implement rolling codes for enhanced security
• Clone card detection
• Mobile phone NFC support

3. JQ6500 MP3 Player Module

Specifications:

• Operating Voltage: 3.2V-5V
• Communication: UART (9600 baud default)
• Supported formats: MP3, WAV
• Storage: Onboard flash memory (varies by model) or SD card
• Audio Output: Direct speaker drive or line out
• Control: Serial commands or button interface
• Current Consumption: ~20mA idle, ~200mA when driving speaker

Current Usage:

• Playing 6 audio tracks:
  1. Power-up sound
  2. “Are you still there” (10s timeout)
  3. Access granted
  4. Access denied (first attempt)
  5. Access denied (second attempt)
  6. Access denied (multiple attempts)
• Serial communication at 9600 baud
• Volume control via software

Available Features Not Yet Used:

• Busy pin for playback status
• Button control interface
• Folder-based organization
• Random playback
• Loop modes
• EQ settings

Future Potential:

• Voice announcements for card holders
• Multi-language support
• Background music/ambience
• Emergency alarm sounds
• Status announcements
• Custom sound effects

4. Relay Module - SRD-05VDC-SL-C (4-Channel)

Specifications:

• Model: SRD-05VDC-SL-C
• Channels: 4 independent relays
• Type: Active LOW (LOW signal = relay ON)
• Operating Voltage: 5V relay coil, 3.3V-5V logic compatible
• Relay Ratings:
  • 10A @ 250VAC
  • 10A @ 125VAC
  • 10A @ 30VDC
  • 10A @ 28VDC
• Isolation: Optocoupler isolated
• Current per relay: ~70-80mA when active
• Contact Form: SPDT (NO/NC/COM)

Current Usage:

• Relay 1: Door lock/unlock (10-second activation)
• Relay 2-4: Currently unused

Available Features Not Yet Used:

• Relay 2: Could control lights
• Relay 3: Could control alarm/siren
• Relay 4: Could control auxiliary systems
• NO/NC contacts for fail-safe/fail-secure
• Status LED on each relay

Future Potential:

• Interior light control
• Engine start/stop
• Alarm system integration
• Garage door control
• Sequential activation patterns
• Power control for other modules

5. Power Supply - Mini360 Buck Converter

Specifications:

• Model: Mini360 DC-DC Buck Converter
• Input Voltage: 4.75V-23V
• Output Voltage: 1V-17V (adjustable)
• Output Current: 1.8A continuous, 3A peak
• Efficiency: Up to 96%
• Switching Frequency: 340kHz
• Size: Ultra-compact module
• Protection: Over-current, thermal shutdown

Current Usage:

• Converting 12V automotive power to stable 5V
• Powering all system components
• Set to 5V output for relay module and component compatibility

Features:

• Adjustable output via trim pot
• High efficiency reduces heat
• Wide input range handles automotive voltage fluctuations
• Compact size for easy integration

Power Considerations

Current Consumption Breakdown

• ESP32-C3: ~100mA (active WiFi), ~20mA (idle), 43μA (deep sleep)
• PN532: ~50mA (average), 150mA (peak)
• JQ6500: ~20mA (idle), 200mA (playing with speaker)
• Relays: ~80mA per active relay
• Total: ~90mA idle, ~350-450mA active

Power Optimization Opportunities

1. ESP32-C3 deep sleep: 43μA
2. PN532 power down: ~10μA
3. JQ6500 standby mode
4. Relay holding current reduction
5. WiFi/BLE power management

Expansion Possibilities

I2C Bus (Pins 8/9 can be configured)

• RTC module (DS3231) for time-based access
• OLED display for status
• Additional EEPROM storage
• Temperature/humidity sensors
• Accelerometer for tamper detection

Remaining Digital Pins

• Emergency button input
• Status LEDs (beyond built-in)
• Buzzer for local alerts
• PIR motion sensor
• Door position sensor

Analog Inputs Available (A0-A5)

• Battery voltage monitoring
• Light sensor for automatic brightness
• Current sensing for each relay
• Potentiometer for volume control

Wireless Capabilities

• WiFi configuration portal
• Mobile app via BLE
• MQTT for home automation
• ESP-NOW mesh networking
• OTA firmware updates

Wiring Diagram

ESP32-C3 SuperMini
┌─────────────────┐
│                 │
│  10 ─────────── │──── PN532 SS
│  MISO ────────── │──── PN532 MISO
│  MOSI ────────── │──── PN532 MOSI
│  SCK ─────────── │──── PN532 SCK
│                 │
│  9 ──────────── │──── Relay 1 (Door)
│  6 ──────────── │──── Relay 2
│  5 ──────────── │──── Relay 3
│  4 ──────────── │──── Relay 4
│                 │
│  1 ──────────── │──── JQ6500 RX
│  0 ──────────── │──── JQ6500 TX
│                 │
│  5V ─────────── │──── Mini360 Output
│  GND ─────────── │──── Common ground
│                 │
└─────────────────┘

Mini360 Buck Converter
┌─────────────────┐
│  IN+ ────────── │──── 12V Vehicle
│  IN- ────────── │──── Vehicle GND
│  OUT+ ───────── │──── 5V to System
│  OUT- ───────── │──── System GND
└─────────────────┘

Best Practices

1. Power Supply: Mini360 provides stable 5V from automotive 12V
2. Wiring: Keep SPI lines short for RFID reliability
3. Grounding: Common ground for all components
4. Protection: Flyback diodes included in relay module
5. Shielding: Keep RFID antenna away from metal/interference
6. Audio: JQ6500 can drive speaker directly

Advantages of New Hardware

ESP32-C3 SuperMini vs Pro Micro

• Processing Power: 160MHz RISC-V vs 8MHz AVR
• Memory: 400KB RAM vs 2.5KB RAM
• Storage: 4MB Flash vs 32KB Flash
• Wireless: Built-in WiFi & BLE vs none
• Size: Similar compact form factor
• Power: More efficient deep sleep modes

JQ6500 vs DFPlayer

• Simplicity: Easier serial protocol
• Reliability: More stable operation
• Integration: Better documentation
• Cost: Similar price point

Mini360 Buck Converter

• Efficiency: Up to 96% vs linear regulators
• Adjustable: Fine-tune output voltage
• Compact: Minimal board space
• Robust: Handles automotive voltage spikes

Troubleshooting Tips

• RFID not reading: Check SPI connections and SS pin
• Relays clicking rapidly: Check 5V supply from Mini360
• Audio issues: Verify JQ6500 serial connections
• WiFi not connecting: Check antenna clearance
• Random resets: Adjust Mini360 output voltage
• BLE issues: Ensure proper power decoupling

This guide will be updated as new features are implemented with the ESP32-C3 platform.