The Raspberry Pi Pico W has proven to be a low-cost, low-power option for users looking to implement network support for their various microelectronics projects. Such is the case today with Maurício Pessoa’s Raspberry Pi Pico W doorbell system that uses Telegram to notify users when the doorbell has been rung.
This project is great for users who might be hearing impaired or otherwise need a visual notification for doorbell alerts. The Pico W connects to Wi-Fi and sends notifications to Telegram using a bot. The notification messages can then be sent to either individual users or predetermined group chats.
According to Pessoa, there are plans in the works to share more details about the hardware configuration. That said, we can infer a bit from the pictures he’s shared so far. The prototype system shows a Pico W connected to a protoboard and breadboard. It’s USB powered and also includes a button for input.
The doorbell uses a 5V signal while the Pico W relies on 3.3V for power. Because of this, a PC817 optocoupler is needed along with a 185 Ohm resistor so it can safely relay the doorbell data to the Pico W before sending the Telegram notification over Wi-Fi. The code for the Pico W doorbell was created from scratch by Pessoa just for the project. It was developed with the Thonny IDE and written in MicroPython.
Pessoa decided to make the project completely open source at GitHub for anyone who wants to explore the code. It’s responsible for both connecting the Pico W to Wi-Fi as well as interacting with the Telegram bot for notifications. There are other ways to send notifications from the Pico W, including via MQTT protocol or IFTTT to Twitter.
If you want to recreate this Raspberry Pi Project, check out the Pico W doorbell project page at GitHub for a breakdown of how it goes together. Be sure to follow Maurício Pessoa for more cool Pi projects and future updates on this one.