DIY Smart Mailbox Validator (OTA-Ready)

Parts List & Smart Mailbox API v1.0

Component	Suggested Model / Notes
Microcontroller	ESP32 or Raspberry Pi Pico W (Wi-Fi + BLE)
Lid Position Sensor	Reed switch + magnet or Hall effect sensor
Mail Detection Sensor	IR breakbeam sensor or weight sensor pad
Locking Mechanism	Servo motor or solenoid latch
Power Supply	5V USB or battery pack (w/ solar trickle optional)
Optional Camera Module	ESP32-CAM or USB camera (for photo capture/logging)
Weatherproof Enclosure	IP65-rated plastic box
QR Code Label	For validator scan/onboarding
Optional: LoRa module	For off-grid message relay (RFM95/96)

Assembly Instructions

Mount the Lid Sensor
Place the reed switch inside the mailbox lid and affix the magnet to the top edge so it triggers when opened.
Install Mail Sensor
Position the IR sensor where mail will break the beam when inserted or rest on the weight pad.
Connect the Microcontroller
Wire sensors to GPIO pins, enable input pull-up/down as needed.
Add Lock/Servo (Optional)
Wire a servo or latch to allow locking/unlocking remotely.
Enclose Components
Mount all components securely in the enclosure. Route cables through sealed grommets.
Power Supply
Use a USB battery bank or solar-powered battery charger. ESP32 sleep modes recommended for efficiency.

Software Features

Wi-Fi or BLE pairing to OTAwallet
CID logging of each open event
Remote lock control (via OTAwallet or QR command)
Validator scan logs (e.g., /device/verify)
Optional: take photo on open + upload to IPFS

IPFS Logging + CID Example

Each event (lid open, mail drop, access attempt) can be logged as:

json{
  "device_id": "mailbox-trusted-01",
  "event": "mail_inserted",
  "timestamp": "2025-05-29T15:03:42Z",
  "cid": "bafy...xyz",
  "validator": "relay1",
  "signature": "..."
}

Integration Hooks

/device/verify from alias_api_server.py
/device/eventlog/:id
/cid/push
OTAwallet “Trusted Mailbox” badge display

Optional Add-ons

NFC tag to identify mail carriers
QR tag for trusted guest access
External LoRa radio for off-grid relay
Integration with SafeSignal for alerts

DIY Smart Mailbox Validator (LoRa + Web3 MAC Auth Gateway)

Architecture Overview

Smart Mailbox Node (Outdoor)
- Battery-powered
- Detects mail, door open, tamper events
- Broadcasts LoRa packets with MAC and CID payloads
LoRa Gateway Node (Indoor)
- Receives LoRa packets from mailbox
- Signs and forwards them to OTAwallet or IPFS
- Maps mailbox MAC → validator wallet address
- Runs lightweight Web3 MAC Gateway (e.g., mac_gateway.py)

🔧 Outdoor Mailbox Node – Parts List

Component	Example / Notes
Microcontroller	Seeeduino Xiao + RFM95 LoRa (or ESP32 w/ LoRa)
LoRa Module	Hope RFM95 (868/915MHz)
Door Sensor	Reed switch or Hall sensor
Mail Sensor	Load cell, IR sensor, or capacitive pad
Tamper Switch	Optional micro switch or accelerometer
Battery Pack	18650 w/ TP4056 charger (solar optional)
Enclosure	Weatherproof IP65 case
QR Tag / Label	For scan-based validator registration

Indoor LoRa Gateway Node – Parts List

Component	Example / Notes
Raspberry Pi	Pi 3/4 or Zero 2W
LoRa Hat/Module	Dragino LoRa HAT, RFM95 on SPI
MAC Auth Software	`mac_gateway.py` with CID builder + IPFS push
OTAwallet Wallet	Installed & linked to this gateway
Optional	OLED screen for real-time CID logs

Data Flow

📬 Mail is inserted → sensor triggers
📡 LoRa packet broadcast: json{ "mac": "B8:27:EB:12:34:56", "event": "mail_inserted", "ts": 1688230093, "sig": "<optional sig>" }
🏠 Gateway receives packet:
- Verifies MAC
- Maps to relay1 validator alias
- Pushes event log to IPFS
- Logs CID locally or to the OTA ledger

Web3 MAC Gateway Logic

python# mac_gateway.py (simplified)
def handle_packet(packet):
    mac = packet["mac"]
    if mac in known_devices:
        cid = ipfs_add(json.dumps(packet))
        log_to_ledger(mac, cid)

known_devices from mac_registry.json
IPFS log includes timestamp + validator alias
All mailbox devices must be pre-registered (or dynamically onboarded via QR scan)

Example IPFS Log Output

json{
  "device": "smart_mailbox_001",
  "mac": "B8:27:EB:12:34:56",
  "event": "door_opened",
  "timestamp": "2025-05-29T16:20:54Z",
  "cid": "bafy...123",
  "verified_by": "relay1"
}

Example OTA gateway

Example Mailbox_node

Mailbox Node Firmware

U.S.-Based LoRa Module Manufacturers

1. Microchip Technology

Modules: RN2483 (868 MHz) and RN2903 (915 MHz)
Features: Integrated LoRaWAN stack, UART interface, low power consumption
Use Case: Ideal for projects requiring reliable LoRaWAN connectivityAmazon+8CDEByte+8Tindie+8

2. MultiTech Systems

Modules: xDot® and mDot™
Features: ARM Cortex-M3, LoRaWAN certified, robust for industrial applications
Use Case: Suitable for large-scale deployments and enterprise solutionseBay+3CDEByte+3Tesswave Technology Limited+3

3. Laird Connectivity

Modules: RM1xx series
Features: Combines LoRa and Bluetooth Low Energy (BLE), flexible integration
Use Case: Great for applications needing both LoRa and BLE connectivityPiShop CDEByte

Development Boards & HATs Compatible with Raspberry Pi

1. Waveshare SX1262 LoRa HAT (915 MHz)

Features: Based on Semtech SX1262, supports UART interface, up to 5 km range
Availability: Available through various U.S. distributors
Use Case: Suitable for Raspberry Pi-based LoRa projectsReddit+4Amazon+4waveshare.com+4 Tindie+2The Things Network+2Embedded+2

2. Adafruit LoRa Radio Bonnet

Features: Built-in OLED display, based on Semtech SX1276, supports 915 MHz
Availability: Sold by Adafruit, a U.S.-based company
Use Case: Ideal for developers seeking a compact solution with display capabilitiesPoshmark+11Embedded+11Tindie+11

Integration Tips for Your Smart Mailbox Project

Frequency Compliance: Ensure the module operates at 915 MHz to comply with U.S. regulations.
Power Considerations: Opt for modules with low power consumption to extend battery life.
Antenna Selection: Use appropriate antennas to maximize range and signal quality.
Firmware Support: Choose modules with robust firmware support and community resources.

Authentication

All endpoints are scoped by the mac_address of the mailbox.
On-chain mapping via validator-signed registration (MAC → Wallet).

`POST /mailbox/event`

Log mailbox events (e.g., mail inserted, door opened).

json{
  "mac": "B8:27:EB:12:34:56",
  "event": "mail_inserted",
  "timestamp": "2025-05-29T17:45:00Z"
}

Returns:

json{
  "cid": "bafybeigdxyz...",
  "verified_by": "relay1"
}

`POST /mailbox/register`

json{
  "mac": "B8:27:EB:12:34:56",
  "tenant_id": "apt_204",
  "wallet": "osmo1xyz...",
  "permissions": ["unlock", "guest_access"]
}

`GET /mailbox/tenant/:tenant_id/mailboxes`

List all mailboxes assigned to a tenant.

Returns:

json[
  {
    "mac": "B8:27:EB:12:34:56",
    "alias": "apt_204_box",
    "status": "locked",
    "last_event": "door_opened"
  }
]

`POST /mailbox/photo`

Capture and upload a snapshot (if equipped).

json{
  "mac": "B8:27:EB:12:34:56"
}

Returns:

json
  "cid": "bafy...img",
  "timestamp": "2025-05-29T17:45:12Z"
}

`POST /mailbox/guest_access`

Share a guest passcode for delivery or temporary access.

json{
  "tenant_id": "apt_204",
  "mac": "B8:27:EB:12:34:56",
  "code": "5147",
  "valid_for": 600
}

`GET /mailbox/logs/:tenant_id`

Fetch mailbox access history (IPFS-backed log).

Returns:

json[
  {
    "event": "mail_inserted",
    "cid": "bafy...xyz",
    "timestamp": "2025-05-29T17:30:12Z"
  }
]

🔒 `POST /mailbox/lock`

Lock or unlock a mailbox.

json{
  "mac": "B8:27:EB:12:34:56",
  "action": "unlock",
  "method": "temp_passcode",
  "passcode": "5147"
}

🛠️ `POST /mailbox/admin/override`

Admin override with signed validator authorization.

json{
  "mac": "B8:27:EB:12:34:56",
  "reason": "lost_key",
  "admin_sig": "validator-signed-hash"
}

📊 `GET /mailbox/status/:mac`

Real-time status of the mailbox.

Returns:

json{
  "door": "closed",
  "flag": "down",
  "lock": "locked",
  "temperature_c": 23.5,
  "battery_percent": 88
}

🧪 `POST /mailbox/simulate`

Send a fake packet for testing purposes (dev only).

json{
  "mac": "B8:27:EB:12:34:56",
  "event": "test_flag_up"
}

Parts List & Smart Mailbox API v1.0

Assembly Instructions

Software Features

IPFS Logging + CID Example

Integration Hooks

Optional Add-ons

DIY Smart Mailbox Validator (LoRa + Web3 MAC Auth Gateway)

Architecture Overview

🔧 Outdoor Mailbox Node – Parts List

Indoor LoRa Gateway Node – Parts List

Data Flow

Web3 MAC Gateway Logic

Example IPFS Log Output

U.S.-Based LoRa Module Manufacturers

1. Microchip Technology

2. MultiTech Systems

3. Laird Connectivity

Development Boards & HATs Compatible with Raspberry Pi

1. Waveshare SX1262 LoRa HAT (915 MHz)

2. Adafruit LoRa Radio Bonnet

Integration Tips for Your Smart Mailbox Project

Authentication

POST /mailbox/event

POST /mailbox/register

GET /mailbox/tenant/:tenant_id/mailboxes

POST /mailbox/photo

POST /mailbox/guest_access

GET /mailbox/logs/:tenant_id

🔒 POST /mailbox/lock

🛠️ POST /mailbox/admin/override

📊 GET /mailbox/status/:mac

🧪 POST /mailbox/simulate

`POST /mailbox/event`

`POST /mailbox/register`

`GET /mailbox/tenant/:tenant_id/mailboxes`

`POST /mailbox/photo`

`POST /mailbox/guest_access`

`GET /mailbox/logs/:tenant_id`

🔒 `POST /mailbox/lock`

🛠️ `POST /mailbox/admin/override`

📊 `GET /mailbox/status/:mac`

🧪 `POST /mailbox/simulate`