Smart Lock

Let's not connect a smart lock to the cloud...

This lock can (also) be opened by SMS through a built-in modem


No internet? No problem

‌This lock is very robust. ‌If the internet is down, SMS will probably still work. This way you can always remotely open the door to guests.

‌Not connecting it to the internet also means it's not exposed to hackers.

Access control

‌You can create (temporary) passwords. This is useful if you have someone who periodically needs to visit a home, for elderly care or a cleaning person. You don't need to give them a key, just a password, which you can revoke at any time.

Two locks, endless flexibility

‌This device can toggle two relays, so it can manage a building door and apartment door at the same time. 

‌You can pick your own electric locks to go with it. If you building already has electric locks you could try to integrate it.

Building the Smart Lock

This one is a bit more involved

Connect the relay

You can actually connect two.

‌The example uses this relay. Connect the first relay to pin 5, and the second to pin 6.

Connect the modem

You will also need to plug a simcard into the modem.

‌This modem is the one you need.

‌Connect the VCC_IN to one of the positive (red) pins, and the GND to any of the negative (black) pins.

‌Connect the TXD (short for "transmit") to pin 4, and the RXD (short for "receive") to pin 3. 

‌Check the code if you like.

Because the modem is relatively power hungry, it needs to be connected to the power source directly. You could use two USB wires, or get a nice splitter cable like in this example. Or... you could only plug in the modem module - it will then provide power to the Arduino.

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

You can buy all the parts yourself, for example on