TTN Setup

The Things Network Setup

Step-by-step guide to register and configure Multiflexmeter 3.7.0 devices on The Things Network (TTN).

Prerequisites

• TTN account (free): https://console.cloud.thethings.network/
• Multiflexmeter 3.7.0 hardware
• Internet connection

Step 1: Create TTN Application

1.1 Log In to TTN Console

1. Navigate to https://console.cloud.thethings.network/
2. Log in with your account
3. Select your region (Europe: eu1.cloud.thethings.network)

1.2 Create Application

1. Click “Create application”
2. Fill in application details:
   • Application ID: multiflexmeter (must be unique)
   • Application name: Multiflexmeter Deployment
   • Description: IoT sensor network for environmental monitoring
3. Click “Create application”

Step 2: Register Device

2.1 Add End Device

1. Open your application
2. Click “Register end device”
3. Select “Enter end device specifics manually”

2.2 Device Configuration

LoRaWAN Version:

• Select: LoRaWAN Specification 1.0.x

Regional Parameters:

• Select: PHY V1.0.2 REV B (or latest for EU868)

Frequency Plan:

• Select: Europe 863-870 MHz (SF9 for RX2 - recommended)

Activation Mode:

• Select: Over the air activation (OTAA)

Why OTAA?

OTAA is more secure than ABP and handles session management automatically.

2.3 Device Identifiers

JoinEUI (AppEUI):

• Leave as default 0000000000000000 OR
• Use custom: 70B3D57ED00B1E57 (example)
• Format: 8 bytes hex (16 characters)

DevEUI:

• Click “Generate” for automatic generation OR
• Enter manually: 0004A30B00F8AC2D (example)
• Format: 8 bytes hex, globally unique
• Note: Must match device EEPROM exactly

AppKey:

• Click “Generate” for secure random key
• Format: 16 bytes hex (32 characters)
• Important: Copy this key! You’ll need it for EEPROM configuration

End Device ID:

• Friendly name: mfm-sensor-001
• Must be unique within application

2.4 Complete Registration

Click “Register end device”

Step 3: Configure Payload Decoder

3.1 Open Payload Formatters

1. In your device view, click “Payload formatters”
2. Select “Uplink”
3. Choose “Custom JavaScript formatter”

3.2 Add Decoder Function

Paste the following JavaScript decoder:

function decodeUplink(input) {
  // FPort 1: Measurement data (16 bytes = 8 × int16)
  if (input.fPort === 1) {
    if (input.bytes.length !== 16) {
      return {
        errors: ["Invalid payload length"]
      };
    }

    var measurements = [];
    for (var i = 0; i < 8; i++) {
      var value = (input.bytes[i * 2] << 8) | input.bytes[i * 2 + 1];
      // Convert to signed int16
      if (value > 32767) value -= 65536;
      measurements.push(value);
    }

    return {
      data: {
        channel_0: measurements[0],
        channel_1: measurements[1],
        channel_2: measurements[2],
        channel_3: measurements[3],
        channel_4: measurements[4],
        channel_5: measurements[5],
        channel_6: measurements[6],
        channel_7: measurements[7]
      }
    };
  }

  // FPort 2: Firmware version (2 bytes)
  if (input.fPort === 2) {
    if (input.bytes.length !== 2) {
      return {
        errors: ["Invalid version payload"]
      };
    }

    var version = (input.bytes[0] << 8) | input.bytes[1];
    var proto = (version >> 15) & 0x01;
    var major = (version >> 10) & 0x1F;
    var minor = (version >> 5) & 0x1F;
    var patch = version & 0x1F;

    return {
      data: {
        version: proto + "." + major + "." + minor + "." + patch,
        version_raw: version
      }
    };
  }

  return {
    warnings: ["Unknown FPort: " + input.fPort]
  };
}

Click “Save changes”

3.3 Test Decoder

Use “Test” tab to verify:

Test Input (FPort 1):

{
  "bytes": [0, 100, 0, 200, 1, 44, 255, 156, 0, 0, 0, 0, 0, 0, 0, 0],
  "fPort": 1
}

Expected Output:

{
  "data": {
    "channel_0": 100,
    "channel_1": 200,
    "channel_2": 300,
    "channel_3": -100,
    "channel_4": 0,
    "channel_5": 0,
    "channel_6": 0,
    "channel_7": 0
  }
}

Step 4: Copy Device Credentials

You’ll need these values for EEPROM configuration:

From TTN Console:

1. Application EUI (AppEUI)

   • Location: Device overview → “Activation information”
   • Format: 70B3D57ED00B1E57
   • Copy: Click copy icon

2. Device EUI (DevEUI)

   • Location: Device overview → “Activation information”
   • Format: 0004A30B00F8AC2D
   • Copy: Click copy icon

3. Application Key (AppKey)

   • Location: Device overview → “Activation information”
   • Click eye icon to reveal
   • Format: 5B7F1A2E3C9D8A6F4E0B2C5D8A3F1E9C
   • Copy: Click copy icon

Security

Never share your AppKey publicly! Store it securely.

Step 5: Configure EEPROM

Use the copied credentials to configure your device EEPROM.

See: Configuration Guide for detailed instructions.

Step 6: Set Up Integrations

6.1 MQTT Integration (Built-in)

TTN provides MQTT access by default:

Connection Details:

• Server: eu1.cloud.thethings.network (or your region)
• Port: 1883 (MQTT) or 8883 (MQTTS)
• Username: multiflexmeter@ttn (your app ID)
• Password: API key (generate in console)

Topics:

# Uplink messages
v3/multiflexmeter@ttn/devices/mfm-sensor-001/up

# Downlink messages
v3/multiflexmeter@ttn/devices/mfm-sensor-001/down/push

6.2 HTTP Integration

1. Go to “Integrations” → “Webhooks”
2. Click “Add webhook”
3. Select “Custom webhook”
4. Configure:
   • Webhook ID: custom-backend
   • Webhook format: JSON
   • Base URL: https://your-server.com/ttn/webhook
   • Uplink message: ✓ Enabled

6.3 Storage Integration

Enable “Storage Integration” (free tier: 24 hours retention):

1. Go to “Integrations” → “Storage Integration”
2. Click “Activate Storage Integration”
3. Access data via API or TTN Console

Step 7: Send Downlink Messages

From TTN Console

1. Open device view
2. Go to “Messaging” → “Downlink”
3. Configure downlink:
   • FPort: 1
   • Payload (hex): 0010012C (set interval to 300 seconds)
   • Confirmed: ✓ (optional, for acknowledgment)
4. Click “Schedule downlink”

Downlink will be sent on next uplink (Class A behavior)

Via API

curl -X POST \
  https://eu1.cloud.thethings.network/api/v3/as/applications/multiflexmeter/devices/mfm-sensor-001/down/push \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "downlinks": [{
      "f_port": 1,
      "frm_payload": "ABAAKg==",
      "priority": "NORMAL"
    }]
  }'

Monitoring

Live Data

View incoming messages:

1. Open device in TTN Console
2. Go to “Live data” tab
3. Watch for uplink messages

Typical Message:

{
  "uplink_message": {
    "f_port": 1,
    "frm_payload": "AGQAyAAszpwAAAAAAAAAAAAA",
    "decoded_payload": {
      "channel_0": 100,
      "channel_1": 200,
      ...
    },
    "rx_metadata": [
      {
        "gateway_ids": { "gateway_id": "my-gateway" },
        "rssi": -45,
        "snr": 9.5
      }
    ]
  }
}

Device Status

Check device health:

• Last seen: Timestamp of last uplink
• Uplink counter: Total messages received
• Downlink counter: Total messages sent
• RSSI: Signal strength (-120 to -30 dBm)
• SNR: Signal-to-noise ratio (>0 dB is good)

Fair Use Policy

TTN Fair Use Limits

Free Tier:

• Uplink: 30 seconds airtime per device per day
• Downlink: 10 downlinks per device per day

Compliance

Typical SF7 message (16 bytes):

• Airtime: ~60ms
• Maximum messages: ~500/day

Recommended intervals:

• SF7: 2-5 minutes
• SF9: 5-10 minutes
• SF12: 15+ minutes

Enable Fair Use Policy in device EEPROM:

FAIR_USE = bytes([0x01])  # Enable

Troubleshooting

Device Not Joining

Check:

1. AppEUI, DevEUI, AppKey match exactly
2. Device is in range of gateway
3. Frequency plan matches region (EU868)
4. Check gateway is online in TTN Console

Debug:

• Enable serial debug on device
• Check for “EV_JOINING” messages
• Verify LoRaWAN parameters in code

---

No Uplinks Received

Check:

1. Device joined successfully (check “Last seen”)
2. Gateway is receiving packets
3. RSSI/SNR values are reasonable (-120 to -30 dBm)
4. Device interval is configured correctly

---

Decoder Not Working

Check:

1. FPort matches (1 for measurements, 2 for version)
2. Payload length is correct (16 bytes for FPort 1)
3. Test decoder with known values
4. Check JavaScript console for errors

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Next Steps

• Configuration - Configure device EEPROM
• Field Deployment - Installation best practices
• Quick Start - Complete setup walkthrough