M5 Doorbell Project Update

Since moving the main entrance, the M5 doorbell has not been operational. The original doorbell at the old entrance also developed a wiring issue in the ceiling, preventing the bell from being rung. I am happy to announce we have a working prototype!

The new M5 doorbell that was designed by Leon Ge and myself fixes this by introducing a UDP (User Datagram Protocol) client and server implemented on two Raspberry Pi Pico Ws. The server sits and waits for a button press from a client, that would be mounted on next to the door to M5, and once it receives the “ring” command, the server uses a relay to ring the doorbell.

This is the current working prototype, the electronics need to be better worked out due to feedback coming from the coil on the bell. We found the bell would draw too much voltage, causing the Pico to turn off. This behavior is called browning out and we used a capacitor to rectify and resist the fluctuation of the voltage

We chose to make the doorbell wireless in order to introduce two of them for each door, since there are times when people are inside M5, and they want to notify people at a specific entrance to come let them in. In order for that to work, a second doorbell chime will be installed, location to be determined at this point.

The functionality can be tested at any time, by using the breadboarded Pico W sitting either on the staff desk or on the shelf of a workstation in the Pi room, just make sure the doorbell Pico W is being powered by plugging in the white extension cord.

This is our current test doorbell! It uses an internal pull-up on a GPIO pin, that’s why no resistor is placed down.

The plan was to demo at staff meeting, so a video in addition to the pictures posted will be added later.