Lolo Musicbox

A simple Raspberry Pi NFC musicbox for children, the NFC tags trigger songs or playlists.

Finished product.

Inside the box.

In action.

Software Setup

Ten steps to setup the Lolo-Musicbox. Some of them will be explained in detail:

1. Prepare SD with Raspbian
2. Configure WIFI and SSH
3. Boot up the Raspberry Pi, connect via SSH, use raspi-conf for basic setup
4. Install Git
5. Clone this repo
6. Run setup.sh
7. check config.py
8. Reboot the Raspberry Pi
9. Copy music onto the Lolo-Musicbox
10. Enjoy

Prepare SD with Raspbian

Tested with 'Raspbian Stretch Lite', see https://www.raspberrypi.org/downloads/raspbian/

Configure WIFI and SSH

To activate WIFI and SSH without booting the Raspberry Pi add the two files to the root directory of the SD.

• To activate SSH add an empty file with the name ssh
• To configure and activate WIFI add a file with the name wpa_supplicant.conf, containing the WIFI configuration.

country=US
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="<the-ssid-of-your-network>"
    scan_ssid=1
    psk="<the-password-to-your-network>"
    key_mgmt=WPA-PSK
}

Basic setup with raspi-config

sudo raspi-config

• Change password: 1.
• Set new hostname to 'lolo': 2.N1.
• Don't wait for network on boot: 3.B1. No
• Set locale: 4.I1
• Set WIFI Country: 4.I4

Install Git

sudo apt-get update && sudo apt-get install git

Clone this repo

cd ~
git clone <url> lolo

Run setup.sh

This installs the required software, registers the Lolo-Musicbox service, and tries to optimize the boot time.

cd ~/lolo
chmod +x setup.sh
./setup.sh

Check config.py

All paths and GPIO pins are defined in config.py. Just check if the current setup, hardware and software, matches the given values in config.py.

Copy music onto the Lolo-Musicbox

See 'How the Lolo-Musicbox' works.

Enjoy

Hardware setup

The musicbox is based on a Raspberry Pi 3+. Additionally I used the following parts:

• MFRC522 RFID/NFC module (library on Github)
• MCP3008, 8-Channel 10-Bit ADC to control the volume with a potentiometer (see: Adafruit tutorial)
• TPA2012, Stereo 2.1W Class D Audio Amplifier (see Adafruit)
• 4 arcade buttons
• RGB LED (with according resistors)
• 2 small 4Ω speakers
• 3.5mm audio jack breakout
• 2 NCR18650B LiIon batteries (3.7V)
• TP4056 LiPo battery charger module
• MT3608, DC-DC Step Up Converter, to step up the 3.7V from the batteries to 5V needed by the Raspberry Pi

Please note, that due to a bug in the Fritzing component, the RST and the GND out-pin of the RC522 reader are switched.

Issues/Learnings/Things that need improvement

• Rethink the wiring and placement of the parts on the perfboard. Short wires and bad placement makes the placement of the perfboard in the case harder than necessary
• Consider using a digital rotary encoder to set the volume. The potentiometer with the AD converter is not very percise and produces 'volume-jumps' from time to time.
• Add a powerswitch to disconnect the battery from the Raspberry Pi. The battery will be drained, even when the Raspberry is shut down. At least it seems like it does.
• The TP4056 battery charger module supports charging and using the battery at the same time, but if the battery charge is to low, the Raspberry Pi will go into a reboot loop. This must be improved.
• Also, the TP4056 gets quite hot when charging the battery. Consider using a heatsink.
• Boot time is still quite long. After starting the box there is about 20s waiting time without any indication that the musicbox was started. Needs imporvement.
• Async LED blinking and pulsing is hard to control, find cleaner solution.