nanowave

nanowave is planned as a DIY portable audio player developed in Rust / Slint. It is currently a proof-of-concept learning project, that has no "release", but some demos, what it should look like.

In general the project is cross-platform / cross-arch, but currently targeted for Linux / Buildroot on x64 and RISC-V 64bit musl.

Here are some pictures of the current state...

3D printed case Prototype

Feature overview

Development Breadboard

Audio playback demo video (audio unfortunately shifted, thanks YouTube): https://www.youtube.com/watch?v=vRbHiqdaSFk

Hardware

Required

• Board: LicheeRV Nano Wifi (~22$)
  • Variant: Bundle: RV NANO-W
  • AliExpress
• Display: IPS 2.28" ST7701S Touch Display LHCM228TS003A (~12$)
  • Variant Screen with Touch
  • AliExpress)
• Audio: USB-C to Audio Jack Adapter, used for audio output (~10$)
  • e.g. Apple
  • Others might work, but only some have been tested
• Storage / OS:
  • Any micro sd card > 4GB
• Power:
  • For getting started, you can use USB-C
  • As soon as you need USB-C for Audio, you can add a stable 5 V power source to the PINs VSYS / GND, either by soldering cables or using clamps
  • You could also use a microcontroller with battery support: ESP32 C6

Power supply considerations Currently I'm in contact with PN Labs to test their promising and very efficient Battery Pal module, because cheaper modules like TP4057 5V and LX-LCBST were producing constant and very annoying noise while listening to audio. Battery Pal seems to have fixed this and other issues, but the tests are still ongoing...

Optional / Work-in-progress

• Battery gauge, e.g. MAX17043 (~5$)
  • Planned for showing the battery percentage - optional

Howto

Below is a small set of shell instructions to prepare a micro sd card for deploying the nanowave project on a LicheeRV Nano.

Best practice

For a good introduction into the LicheeRV Hardware, you can take a look at this: https://github.com/scpcom/LicheeSG-Nano-Build/blob/develop/best-practice.md

Prepare the LicheeRV

# please change this to your liking
DEVICE="/dev/sdXX"
BOOT_MOUNTPOINT="/tmp/lichee-boot"
WIFI_SSID="<your-wifi-ssid>"
WIFI_PASS="<your-wifi-password>"

# NO CHANGES FROM HERE

# become root
sudo -s

# change to tmp
cd /tmp/

# download forked lichee rv nano image
wget https://github.com/scpcom/LicheeSG-Nano-Build/releases/download/v2.3.4-54/licheervnano-e_sd.img.xz

# flash image onto device
xzcat licheervnano-e_sd.img.xz | sudo dd of=$DEVICE bs=100M status=progress conv=fsync

# mount boot partition of the image
mkdir -p "$BOOT_MOUNTPOINT"
mount "${DEVICE}1" "$BOOT_MOUNTPOINT"

# enable display support
echo "panel=st7701_lhcm228ts003a" > "$BOOT_MOUNTPOINT/uEnv.txt"

# enable framebuffer
touch "$BOOT_MOUNTPOINT/fb"

# switch usb port from USB OTG (device emulation) to host mode (devices can be connected) 
rm "$BOOT_MOUNTPOINT/usb.dev" && touch "$BOOT_MOUNTPOINT/usb.host"

# enable check for audioplayer autorun
touch "$BOOT_MOUNTPOINT/audioplayer"


cat <<EOF >> "$BOOT_MOUNTPOINT/wpa_supplicant.conf"
ctrl_interface=/var/run/wpa_supplicant
ap_scan=1
network={
    ssid="$WIFI_SSID"
    psk="$WIFI_PASS"
}
EOF

Build and deploying nanowave player

You need:

• Linux
• Docker (a custom docker image is required to deploy for RISC-V 64bit musl)
• Rust

Building the binaries:

./build-cross.sh

Copying the binaries to the prepared LicheeRV (lichee is the hostname, so adjust this if required, e.g. to the ip address of the LicheeRV):

scp ./target/riscv64gc-unknown-linux-musl/release/nanowave-ui lichee2:/root/nanowave
scp ./scripts/* lichee:/root/

Preparing media

By default nanowave will look for a directory ./media containing ./media/audiobooks (music is not working atm). To provide some audio files, it is recommended to copy a valid audio book file to /root/media/audiobooks/testing.m4b so that nanowave can show and play some content.

Running the player

First you need to ssh into the LicheeRV:

ssh -l root lichee

After you are logged in you can do the following:

# start the audio player manually
/root/audioplayer

# stop the audio player (display keeps on showing the ui)
/root/kill-audioplayer

# enable autorun for audioplayer on boot
grep -q '/boot/audioplayer' /etc/rc.local || cat <<EOF >> "/etc/rc.local"

# nanowave-ui autorun
if [ -e /boot/audioplayer ]
then
        /root/audioplayer
fi
EOF