Smart lock

Open the door, anytime, anywhere.

Without connecting the lock to the internet

Password protected

And you control which phone numbers it will respond to.

Control 2 doors 

Manage both your apartment door and front door with one device.

Cloudless, using S‌MS 

Lock and unlock the door from anywhere by sending an SMS.

Fail safe

You decide what should happen when the power fails. 

Creating the lock

A‌proximate build time: 60 minutes.

Connect the relay(s)

Connect the IN pin of the relay to signal signal pin 5. 

If you would like to control two electric locks, connect the IN pin of the second relay to signal pin 6.

Electric locks can either be locked when they are not powered ("fail secure") or unlocked ("fail safe"). In the example above, the flow of electricity to the electric lock is "normally open" (N.O.), which means no electricity flows to your lock unless the relay is activated. 

If you prefer that when the smart lock activates it interrupts the flow of electricity, then use the "normally closed" (N.C.) port of the relay instead.

Connect the GSM modem

Connect its U_TXD (Transmit) pin to signal pin 3, and connect its U_RXD (Receive) pin to signal pin 4. Connect a GND pin on the modem to a GND pin on the expansion board.

Make sure the antenna is screwed on securely.

Connect the USB splitter cable (optional)

This will allow you to power both the RF Nano and the GSM modem from a single USB charger. Connect the longer part to the RF nano.

Alternatively, you could just use two separate normal USB cables that are both connected to a charger with two USB ports.

Important: make sure your charger can supply at least 2.4 amps.

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.

Shopping list

This shopping list on Aliexpress will get you everything in one go.
Micro USB splitter cable
Sep 02, 2019

Power two micro USB devices with one plug. While optional, this is useful if you would like to place two devices in a single…

Aug 27, 2019

‌A basic relay that can toggle the power or a connection to another device. The central port is ground. Besides it you…

RF-Nano Arduino
Aug 10, 2018

The RF-Nano is an Arduino Nano with built-in wireless connectivity. It's the brain of all Candle devices.

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…

SMS modem
Aug 07, 2018

This A6 GPRS modem allows you to send and receive SMS. It has a Micro-USB port which makes it easy to provide it with the…

Expansion board
Aug 06, 2018

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