Energy Consumption Dashboard

Monitor real-time power consumption of your home or workshop using a non-invasive current transformer. Data is logged to InfluxDB for historical analysis and displayed on live dashboard charts with configurable alerts.

Flow Architecture

[ADS1115] --> [Function: Calculate RMS & Power] --> [InfluxDB Write] --> [Chart: Real-time Line]
    (1s poll, A0)       (Vrms x Irms x PF)              (energy_monitor db)      (power over time)
                               |
                               v
                      [Switch: > Threshold] --> [Telegram: Alert]
                        (power > 3000W)          ("High power usage!")

What You'll Need

Wiring Diagram

SCT-013 Current Transformer          ADS1115 ADC             Raspberry Pi
==============================       ===========             ============

 Mains Wire (LIVE only)              VDD ---- 3.3V (Pin 1)
    |                                GND ---- GND  (Pin 6)
    | [Clamp around wire]            SCL ---- GPIO3 (Pin 5)
    |                                SDA ---- GPIO2 (Pin 3)
    +--- Wire 1 --- Burden 33Ω ---+--- A0  (Analog Input)
    |                              |
    +--- Wire 2 ---+--- GND ------+
                    |
              10µF Cap (optional)
                    |
                   GND

ADDR pin: GND = 0x48 (default)
          VDD = 0x49
          SDA = 0x4A
          SCL = 0x4B

Step-by-Step Setup

sudo raspi-config nonint do_i2c 0
sudo i2cdetect -y 1
# Should show device at address 0x48

# Install InfluxDB 2.x
curl -sL https://repos.influxdata.com/influxdata-archive.key | sudo apt-key add -
sudo apt install influxdb2

# Create bucket via CLI
influx bucket create \
  --name energy_monitor \
  --retention 90d \
  --org my-org

# Note your API token for EdgeFlow config

Power Calculation Formula

The SCT-013 outputs an AC signal proportional to the mains current. The function node samples multiple readings per cycle, calculates the RMS value, then multiplies by the mains voltage and power factor to get real power in watts.

Function Node: Calculate RMS and Power

// Calculate RMS current and power from ADS1115 voltage reading
// SCT-013-030: 30A range, 1V output at rated current
// Burden resistor: 33 ohms

var voltage = msg.payload;          // Raw voltage from ADS1115
var MAINS_VOLTAGE = 230;            // Change to 120 for US/Canada
var POWER_FACTOR = 0.95;            // Typical residential PF
var CT_RATIO = 1800;                // SCT-013-030 turns ratio
var BURDEN_R = 33;                  // Burden resistor in ohms

// Convert ADC voltage to current
// SCT output voltage = (I_primary / CT_RATIO) * BURDEN_R
// So: I_primary = (V_measured * CT_RATIO) / BURDEN_R
var current_rms = (voltage * CT_RATIO) / BURDEN_R;

// Calculate power
var power_watts = MAINS_VOLTAGE * current_rms * POWER_FACTOR;

// Accumulate energy (kWh)
var prev = context.get('energy_kwh') || 0;
var prev_time = context.get('last_time') || Date.now();
var elapsed_hours = (Date.now() - prev_time) / 3600000;
var energy_kwh = prev + (power_watts * elapsed_hours / 1000);

context.set('energy_kwh', energy_kwh);
context.set('last_time', Date.now());

msg.payload = {
    current_rms: Math.round(current_rms * 100) / 100,
    power_watts: Math.round(power_watts),
    energy_kwh: Math.round(energy_kwh * 1000) / 1000,
    voltage_mains: MAINS_VOLTAGE,
    power_factor: POWER_FACTOR,
    timestamp: Date.now()
};

return msg;

Configuration Details

Complete Flow JSON

Copy and import this flow into EdgeFlow via Menu → Import.

{
  "name": "Energy Consumption Dashboard",
  "nodes": [
    {
      "id": "ads1115_1",
      "type": "ads1x15",
      "name": "Current Sensor",
      "chip": "1115",
      "address": "0x48",
      "channel": 0,
      "gain": 1,
      "interval": 1000,
      "x": 120,
      "y": 200
    },
    {
      "id": "func_rms",
      "type": "function",
      "name": "Calculate RMS & Power",
      "code": "var voltage = msg.payload;\nvar MAINS_VOLTAGE = 230;\nvar POWER_FACTOR = 0.95;\nvar CT_RATIO = 1800;\nvar BURDEN_R = 33;\nvar current_rms = (voltage * CT_RATIO) / BURDEN_R;\nvar power_watts = MAINS_VOLTAGE * current_rms * POWER_FACTOR;\nvar prev = context.get('energy_kwh') || 0;\nvar prev_time = context.get('last_time') || Date.now();\nvar elapsed_hours = (Date.now() - prev_time) / 3600000;\nvar energy_kwh = prev + (power_watts * elapsed_hours / 1000);\ncontext.set('energy_kwh', energy_kwh);\ncontext.set('last_time', Date.now());\nmsg.payload = { current_rms: Math.round(current_rms * 100) / 100, power_watts: Math.round(power_watts), energy_kwh: Math.round(energy_kwh * 1000) / 1000, voltage_mains: MAINS_VOLTAGE, power_factor: POWER_FACTOR, timestamp: Date.now() };\nreturn msg;",
      "x": 360,
      "y": 200
    },
    {
      "id": "influx_write",
      "type": "influxdb-out",
      "name": "Log to InfluxDB",
      "url": "http://localhost:8086",
      "org": "my-org",
      "bucket": "energy_monitor",
      "measurement": "power_readings",
      "token": "YOUR_INFLUXDB_TOKEN",
      "x": 600,
      "y": 160
    },
    {
      "id": "chart_power",
      "type": "chart",
      "name": "Power Chart",
      "chartType": "line",
      "group": "Energy Dashboard",
      "label": "Real-time Power (W)",
      "yAxisLabel": "Watts",
      "x": 820,
      "y": 160
    },
    {
      "id": "switch_alert",
      "type": "switch",
      "name": "High Power?",
      "property": "payload.power_watts",
      "rules": [
        { "type": "gt", "value": 3000 }
      ],
      "x": 600,
      "y": 280
    },
    {
      "id": "func_alert_msg",
      "type": "function",
      "name": "Format Alert",
      "code": "msg.payload = '⚠ High power usage detected!\nCurrent: ' + msg.payload.current_rms + ' A\nPower: ' + msg.payload.power_watts + ' W\nEnergy today: ' + msg.payload.energy_kwh + ' kWh';\nreturn msg;",
      "x": 820,
      "y": 280
    },
    {
      "id": "telegram_alert",
      "type": "telegram",
      "name": "Send Alert",
      "botToken": "YOUR_BOT_TOKEN",
      "chatId": "YOUR_CHAT_ID",
      "x": 1040,
      "y": 280
    }
  ],
  "connections": [
    { "from": "ads1115_1", "to": "func_rms" },
    { "from": "func_rms", "to": "influx_write" },
    { "from": "influx_write", "to": "chart_power" },
    { "from": "func_rms", "to": "switch_alert" },
    { "from": "switch_alert", "to": "func_alert_msg", "port": 0 },
    { "from": "func_alert_msg", "to": "telegram_alert" }
  ]
}

Expected Output

Each second, the function node outputs a message like this:

{
  "payload": {
    "current_rms": 4.82,
    "power_watts": 1053,
    "energy_kwh": 2.418,
    "voltage_mains": 230,
    "power_factor": 0.95,
    "timestamp": 1707753600000
  }
}

Troubleshooting