# Boron LTE Security Device Wiring Diagram ## Complete System Wiring ``` ┌────────────────────────────────────┐ │ PARTICLE BORON LTE │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │ 3V3 │ │ RST │ │VBAT │ │ GND │ │ │ └─────┘ └─────┘ └─────┘ └─────┘ │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │ A0 │ │ A1 │ │ A2 │ │ A3 │ │ │ └─────┘ └─────┘ └─────┘ └─────┘ │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │ A4 │ │ A5 │ │ SCK │ │MISO │ │ │ └─────┘ └─────┘ └─────┘ └─────┘ │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │MOSI │ │ D8 │ │ D7 │ │ D6 │ │ │ └─────┘ └─────┘ └──┬──┘ └─────┘ │ │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │ D5 │ │ D4 │ │ D3 │ │ D2 │ │ │ └─────┘ └─────┘ └──┬──┘ └──┬──┘ │ │ │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │ D1 │ │ D0 │ │ TX │ │ RX │ │ │ └─────┘ └─────┘ └─────┘ └─────┘ │ │ │ │ ┌─────┐ ┌─────┐ ┌─────┐ ┌─────┐ │ │ │ GND │ │ GND │ │ VIN │ │ EN │ │ │ └──┬──┘ └─────┘ └──┬──┘ └─────┘ │ └─────┼─────────────────┼────────────┘ │ │ │ │ ┌───────────┼─────────────────┼───────────┐ │ │ │ │ │ │ │ │ ┌─────────▼─┐ ┌─▼─┐ ┌─▼─┐ ┌─▼─────────┐ │ MICROSWITCH│ │GND│ │VIN│ │ LI-PO │ │ NC │ └───┘ └───┘ │ BATTERY │ │ ┌───┐ ┌───┐│ │ │ │ │COM│ │ NC││ │ 3.7V │ │ └─┬─┘ └─┬─┘│ │ 5000mAh+ │ └───┼─────┼──┘ └───────────┘ │ │ │ │ └──────────────────────────────────────────────┘ │ │ │ │ ┌────▼────┐ │ │ D2 │◄──────────────────────────────────────────────┘ │(INPUT) │ └─────────┘ ┌─────────────────────────────────────┐ │ ALARM CIRCUIT │ │ │ │ D3 ──┬── 1kΩ ──┬── BASE │ │ │ │ (2N2222) │ │ GND ┌▼┐ │ │ │ │ │ │ │▼│ │ │ └┬┘ │ │ │ │ │ │ EMITTER │ │ │ │ │ GND │ │ │ │ │ COLLECTOR │ │ │ │ │ ┌─────▼─────┐ │ │ │ SIREN │ │ │ │ 12V │ │ │ │ 2A MAX │ │ │ └─────┬─────┘ │ │ │ │ │ ┌─────▼─────┐ │ │ │ VIN │ │ │ │ (3.7-12V)│ │ │ └───────────┘ │ └─────────────────────────────────────┘ ┌─────────────────────────────┐ │ OPTIONAL SOLAR │ │ │ │ ┌─────────────────────┐ │ │ │ SOLAR PANEL │ │ │ │ 6V 1W+ │ │ │ └──────┬──────────────┘ │ │ │ │ │ ┌──────▼──────────────┐ │ │ │ CHARGE CONTROLLER │ │ │ │ (SparkFun Sunny │ │ │ │ Buddy) │ │ │ └──────┬──────────────┘ │ │ │ │ │ └───────┬───────────┘ │ │ └─────────────────┼───────────── │ ┌──────▼──────┐ │ LI-PO │ │ BATTERY │ │ + JST │ │ CONNECTOR │ └─────────────┘ ``` ## Pin Connections Summary | Component | Boron Pin | Connection Type | Notes | |-----------|-----------|-----------------|-------| | **Microswitch Common** | D2 | Digital Input (Pullup) | NC switch configuration | | **Microswitch NC** | GND | Ground | Normally closed contact | | **Alarm Control** | D3 | Digital Output | Controls transistor base | | **Status LED** | D7 | Built-in | On-board LED | | **Battery Positive** | VIN | Power Input | 3.7V Li-Po nominal | | **Battery Negative** | GND | Ground | Common ground | ## Microswitch Detail ``` MICROSWITCH (NC - Normally Closed) Normal State (Secured): ┌─────────────┐ │ │ ● │ ← Actuator pressed │ ──┼─── │ │ COM │ NC │ │ ● │ ● │ └─────┼──┼────┘ │ │ │ └─── GND (Boron) ──┐ │ │ └───── D2 (Boron) ────┼─── CLOSED CIRCUIT │ D2 = HIGH (3.3V) ┌▼┐ │ │ 10kΩ internal pullup │▼│ └┬┘ │ 3V3 Breach State (Triggered): ┌─────────────┐ │ ● │ ← Actuator released │ │ │ COM NC │ │ ● ● │ ← OPEN CONTACTS └─────┼───┼───┘ │ │ │ └─── GND (Boron) ──┐ │ │ └──── D2 (Boron) ──────┼─── OPEN CIRCUIT │ D2 = LOW (0V via GND) ┌▼┐ │ │ Current flows to GND │▼│ └┬┘ │ GND ``` ## Alarm Driver Circuit Detail ``` TRANSISTOR ALARM DRIVER (NPN 2N2222) Alarm OFF (D3 = LOW): D3 ──┬── 1kΩ ──┬── BASE = 0V │ │ GND ┌▼┐ No base current │ │ Transistor OFF │▼│ └┬┘ │ GND EMITTER = 0V │ COLLECTOR = Floating │ ┌─────▼─────┐ │ SIREN │ ← No current flow │ OFF │ SIREN = OFF └─────┬─────┘ │ VIN (Battery voltage) Alarm ON (D3 = HIGH): D3 ──┬── 1kΩ ──┬── BASE = 3.3V │ │ GND ┌▼┐ Base current flows │ │ Transistor ON │▼│ └┬┘ │ GND EMITTER = 0V │ COLLECTOR = ~0V (saturated) │ ┌─────▼─────┐ │ SIREN │ ← Current flows VIN→Siren→Collector │ ON │ SIREN = ON (Full battery voltage) └─────┬─────┘ │ VIN (Battery voltage) ``` ## Power Distribution ``` POWER SYSTEM ARCHITECTURE ┌─────────────────┐ ┌──────────────────┐ │ SOLAR PANEL │ │ LI-PO BATTERY │ │ 6V 1W │ │ 3.7V │ │ │ │ 5000-10000mAh │ └────────┬────────┘ └─────────┬────────┘ │ │ │ ┌────────▼────────┐ └──────────────┤ CHARGE CONTROLLER├─── OPTIONAL │ (Sunny Buddy) │ └────────┬────────┘ │ ┌───────────────▼───────────────┐ │ BATTERY OUTPUT │ │ (JST Connector) │ └───────────────┬───────────────┘ │ ┌──────────▼──────────┐ │ BORON VIN/GND │ │ (Power Input) │ └──────────┬──────────┘ │ ┌───────────────▼───────────────┐ │ BORON POWER MGMT │ │ • 3.3V Logic Supply │ │ • Cellular Radio Power │ │ • GPIO Power (D3→Alarm) │ └───────────────────────────────┘ ``` ## Component Specifications ### Microswitch Requirements - **Type**: SPDT (Single Pole, Double Throw) with NC contact - **Voltage Rating**: 12V+ (any standard microswitch) - **Current Rating**: 100mA+ (very low current for digital input) - **Mechanical Life**: 10M+ cycles for reliability - **Mounting**: Panel mount or lever actuated - **Examples**: Cherry D44X, Omron SS-5GL, Honeywell 1SW1-1 ### Alarm Device Options - **Low Power Buzzer**: 3-12V, <100mA (direct drive from D3) - **High Power Siren**: 12V, 500mA-2A (requires transistor driver) - **Strobe Light**: 12V, 200-500mA (requires transistor driver) - **Relay Output**: For AC-powered alarms (requires relay driver) ### Transistor Driver (for High Power Alarms) - **Type**: NPN switching transistor - **Part**: 2N2222, 2N3904, or similar - **Ratings**: - Collector Current: 500mA+ (for siren load) - Collector-Emitter Voltage: 12V+ - Base Current: ~3mA (from D3 via 1kΩ resistor) ### Battery Specifications - **Chemistry**: Lithium Polymer (Li-Po) or Lithium Ion (Li-Ion) - **Voltage**: 3.7V nominal (4.2V max, 3.0V min) - **Capacity**: 5000-10000mAh for 2+ year operation - **Connector**: JST or similar for easy replacement - **Protection**: Built-in protection circuit recommended - **Temperature Range**: -10°C to +60°C for outdoor use ### Solar Panel (Optional) - **Voltage**: 6V (to charge 3.7V battery via controller) - **Power**: 1W minimum, 2W+ recommended for northern climates - **Type**: Monocrystalline for efficiency - **Weather Rating**: IP65+ for outdoor installation - **Charge Controller**: Required to prevent overcharge - SparkFun Sunny Buddy - Adafruit Universal USB/Solar Lithium Ion/Polymer charger - Similar MPPT solar charge controller ## Installation Notes ### 1. Microswitch Mounting - Mount securely to door/window frame - Ensure proper gap (1-2mm) when closed - Test mechanical operation before wiring - Consider vibration and weather exposure ### 2. Alarm Device Placement - Position for maximum deterrent effect - Protect from weather if outdoor installation - Ensure adequate power capacity (check battery drain) - Test audibility at intended range ### 3. Enclosure Requirements - **Rating**: IP65+ for outdoor use - **Size**: Accommodate Boron + battery + connections - **Access**: Serviceable battery compartment - **Mounting**: Secure mounting points - **Ventilation**: Battery safety (avoid gas buildup) ### 4. Power System - Use proper JST connectors for battery - Include inline fuse (2A) for protection - Secure all connections against vibration - Label positive/negative clearly - Test polarity before connecting ### 5. Testing Procedure 1. **Bench Test**: Verify all connections with multimeter 2. **Power Test**: Check current consumption in sleep mode 3. **Function Test**: Trigger microswitch, verify alarm 4. **Range Test**: Verify cellular signal at installation site 5. **Endurance Test**: 24-hour operation test before deployment