Energy use sensor

privacy friendly insight into your energy use

Only track what you need‌ 

device
Protect privacy

Live data can be disabled at any time. (Hourly and daily totals will still be transmitted.)

Choose what you log

Our tip: Improve privacy by only logging hourly or daily totals.‌ 

One size fits all

The sensor counts the light pulses on your home's electricity meter.

Use less energy

It can be confronting to see how much a new device raises your average electricity use.

  • Electricity use sensor

    By designer Jesse Howard

    Learn more
  • Light logging

    Log daily or hourly averages instead of live data

  • Electricity use sensor

    Temporarily disable live tracking to protect privacy

M‌ost smart meters are not privacy friendly 

Around the world electricity companies are pushing home owners to install smart meters.

Each electric device in your home has a unique power usage fingerprint. By using "power disaggregation" algorithms your supplier could figure out which specific devices you own.

If you ask them, your supplier could promise to disable measuring your data remotely. But then you are still handing them the power to potentially re-enable this at any time. Not to mention the security issues.

Candle shows that you don't need to connect your meter to the cloud to get its benefits.

Creating the sensor

A‌pproximate build and install time: 20 to 40 minutes.

Connect the light pulse sensor

Connect its D0 (data) pin to signal pin 2 on the expansion board.

Connect its VCC (positive) pin to any VCC pin on the expansion board, and connect its GND (negative/ground) pin to any GND pin on the expansion board.

The sensor-LED will have to be placed on top of the pulsating LED of your home's electricity meter. You may have to tweak the sensitivity of the sensor by taking a small screw driver and turning the blue variable resistor.

Connect the OLED screen

Connect its SDA (data) pin to signal pin A4 on the expansion board, and connect its SCL (clock) pin to signal pin A5 on the expansion board.

Connect its VCC (positive) pin to any VCC pin on the expansion board, and connect its GND (negative/ground) pin to any GND pin on the expansion board.

Plug in the Arduino

Plug in the RF-Nano Arduino

Plug the RF-Nano into its socket. The USB connector should be on the outside of the main board.

Open the Candle Manager

Select the Candle Manager from the menu, and follow the steps. It will help you upload the code to your new creation.

Add your new device

Visit the Candle controller and on the things page press the (+) icon. Your new creation should be available. Optionally, select which of its properties you'd like to have in the spotlight. Click on "save" to complete the proces.

D‌one! 

Why don't you share the news with a friend, without using social media?

The advanced version created by designer Jesse Howard uses a touch screen instead of an OLED screen. It can display live and historic usage data.

Shopping list

This shopping list on Aliexpress will get you everything in one go.
Small OLED screen
Jan 21, 2019

This small screen is built with OLED technology. It uses very little power.

Dupont wire
Aug 09, 2018

These wires allow you to easily connect the main board to sensors and actuators. They snugly fit over the pins. No soldering…

Light pulse sensor
Aug 06, 2018

This 'photo diode' can count the light pulses that your electricity meter gives off.

Expansion board
Aug 06, 2018

This expansion board makes it easy to connect everything by just plugging in wires.