This makes your keyholder smart. Be notified, whenever keys are added or removed.
The project runs on a Nodemcu Esp8266 board. It integrates with Blynk
I 3d printed the keyholder with the following stl file: https://www.thingiverse.com/thing:665048 Then I glued adhesive copper tape at the sides of the holder hooks Afterwards I drilled little holes in it and fit wires from the back to the holders. Then I soldered the wires to the holder
Find the Nodemcu Pinout here
| Wire | GPIO Pin | Nodemcu Pin |
|---|---|---|
| All black wires | Ground | Ground |
| Key 0 | 5 | d1 |
| Key 1 | 4 | d2 |
| Key 3 | 14 | d5 |
| Key 4 | 12 | d6 |
| Key 5 | 13 | d7 |
The blynk app uses the Table and the Notification widget. After you created your app, add the API Key at Line 17 in your code.
The ESP8266 uses the wifimanager library to manage your credentials. When you first run the code, the ESP launches a server and provides a wifi network with the SSID NodeMCU to which you can connect. There you can select your wifi network and enter the password. The password is then stored on the memory of the ESP and is used for all future connections with the network.
Now add a key with a conducting keyring to your smart keyholder. You should get a notification telling you which key was added or removed. Additionally the table in your blynk app will be updated.