Project:Enhanced Door Bell

ProjectInfoBox Enhanced Door Bell

Status:	released
Release Date:	November 2018
Initiator:	Martin, Johannes
Team:	Martin, Johannes
Materials Used:	ESP32
Tools Used:	3D Printer
Software Used:	custom development

Our Workshop is equipped with speakers in each room which can be controlled centrally. Issue #2 describes these speakers in a little bit more detail.
When discussing a proper usage of these speakers, we came up with the idea of building an enhanced door bell, which should be capable of playing custom sounds and be heard in each and every room.

Features

Play MP3 Files
Play sound in every room
Custom bell button
MQTT Control
Code separation between critical (Door Bell Task) and optional (MQTT stuff) Task.

Hardware

The door bell is based on a ESP32 and thus has integrated WiFi Control.
In order to play MP3 Files, we are using a MP3 shield based on the VS1053B.
The whole thing is powered by a 24V notebook power supply which is attached to the speaker cables.
It is enclosed in a custom casing.

Wiring

For the wiring, please see the fritzing sketch on the right or check the original file on GitHub.
Unfortunately, there was no fritzing part available for the ESP32 board we are using (DEVKIT V1). Therefore, the fritzing sketch does not contain the connection between the ESP and the MP3 board.
The VS1053 is attached to the ESP as follows:

VS1053 Pin	ESP Pin
5V	5V
GND	GND
DREQ	D13
X-CS	D5
X_DCS	RX2 (D16)
X_RESET	EN
CS	TX2 (D17)
MOSI	D23
MISO	D19
SCK	D18

Software

You can find the software over on GitHub.

In order to make the ESP32 work with the VS1053B board, we are using a fork of the Adafruit VS1053 Library.

In addition, we are using PubSubClient as the MQTT Client of our choice.

MQTT Integration

/DoorBell/Ring

At every press of the bell button, the door bell publishes "Ring Ring" to the /DoorBell/Ring topic.

/DoorBell/Control

In order to control the door bell, cou can send a JSON to the /DoorBell/Control topic.
The JSON should (for example) look as follows:
{ 'command': 'play', 'payload': '/track001.mp3' }
Within the JSON, the following commands are available:

Command	Expected Payload	purpose
play	filename to play	plays the given filename
selectRingFile	filename to use as the ringtone	sets the given filename as the future ringtone
setVolume	Volume (lower numbers = higher Volume)	sets the given Volume
listSD	folder to list (e.g. '/' for listing all content)	publishes the content of the SD card to /DoorBell/Answer
listconfig	none	publishes the current configuration to /DoorBell/Answer

Ringtone Randomization

There is a python script over at GitHub, which makes use of the above-mentioned MQTT commands in order to get a list of available ringtones and randomly select one.

It is scheduled via a cronjob, so every day you come in to the space, there should be a new ringtone waiting for you.

On the SD-Card, the Ringtones have to be in the folder /Ringtones/. Please be aware that any file in this folder might be chosen as a ringtone. So be careful, what you put there!