Using botwave without a raspberrypi

This page describes how to install BotWave and use it on a non-raspberry-pi device.

It will only cover the BotWave client/local component, since the server has no special hardware requirements and can be installed on any linux machine following the existing guide.

The Root Cause

Without special settings, the BotWave client or local client can't start broadcasts without immediately stopping, due to the lack of the hardware the backend requires.

The bw_custom backend uses the Raspberry Pi General Purpose Clock output to produce FM on the GPIO 4 pin. Regular computers, or newer Raspberry Pi models don't have this component anymore, thus resulting in the backend stopping when trying to access the device.

If you wish to know more about backends, refer to the For Developers/Integrating custom backends page — this guide will stay high level.

The rest of this tutorial will describe how to use another backend to redirect the audio to another device.

Installing

Installing BotWave client on a regular computer is the exact same process as the regular installation. The only different thing is that it'll ask you for install confirmation since it'll detect a non-compatible device.

Installing Another Backend

As this guide is written, the only other existing backend implementation is bw_jack. Instead of broadcasting audio on FM, it sends it into an ALSA card on your computer.

bw_jack isn't installed by the BotWave install script — it's a separate project, written and maintained independently, that you'll need to download and build yourself. That sounds scarier than it is; it's four short steps.

1. Install the dependencies

bw_jack is written in C and needs two development libraries to compile: one for talking to ALSA, and one for reading audio files.

sudo apt install libasound2-dev libsndfile1-dev

Note

If you're not on a Debian/Ubuntu-based system (so apt doesn't exist on your machine), install the equivalent packages with your distro's package manager. For example libasound2-dev is called alsa-lib-devel on Fedora.

2. Get and compile bw_jack

cd /opt/BotWave/backends/
sudo git clone https://github.com/douxxtech/bw_jack
cd bw_jack
gcc bw_jack.c -o bw_jack -lasound -lsndfile

If this succeeds, you'll have a new file called bw_jack in the folder — that's your compiled backend, ready to be picked up by BotWave.

Note

Don't have gcc or git? Install them first with sudo apt install gcc git.

3. Point BotWave to it

BotWave caches the backend path after the first successful broadcast, so the first run needs a couple of extra environment variables to force it to pick up bw_jack instead of bw_custom:

BACKEND_BYPASS_CACHE=true BACKEND_PATH=/opt/BotWave/backends/bw_jack/bw_jack TALK=true sudo -E bw-local

Note

The -E flag on sudo tells it to keep your current environment variables instead of resetting them. Without it, the variables above wouldn't reach BotWave once it's running as root.

Once you're in the botwave > prompt, start any broadcast, this is what actually makes BotWave lock in the new path:

start <any audio file>
# or
live

Tip

After this first broadcast, the path is cached. Future sessions can just use sudo bw-local, no environment variables needed.

You're ready!

Head over to Main/Basic Usage to start broadcasting. Every command you'd normally use (start, live, queue, etc.) works exactly the same way — the only difference is your audio comes out of a sound card instead of over FM, so you won't need an antenna, and you'll want speakers, headphones, or another device plugged into that card to actually hear anything.

Note

bw_jack looks for a sound card named bcm2835 Headphones by default (the Raspberry Pi's built-in audio jack), and falls back to plughw:0,0 if that's not found. On a regular computer, you'll almost always be using that fallback, which is generally your default sound card. If you specifically want to target a different card, you currently have to edit the DEVICE_NAME macro near the top of bw_jack.c and recompile it. There's no way to pick a card at runtime yet.