#420 CuttleTalk

Playing audio from a Boldport Cuttle (Arduino) over LiFi with lite2sound

Here’s a quick demo..

NB: or just a short CuttleTalk clip

Notes

Now I’ve built the Boldport lite2sound, time to test it out. I’m inspired by LEAP#417 SimpleSamplePlayer to attempt some LiFi audio transmission by light.

I’m using the Boldport Cuttle (an AVR/Arduino clone) to transmit an audio sample with an LED, and the Boldport lite2sound as a receiver. The audio out from lite2sound is amplified with LEAP#210 TDA7297 Kit

W00t, and it works;-)

Sampling Some Sound

I’ve cheekily snaffled a sample from Boldport’s Intro to the Boldport Variety Show! using node-ytdl and ffmpeg to capture MP3 audio from the video:

ytdl https://youtu.be/VBJBxnPkQbE --filter audioonly -o intro.mp4
ffmpeg -i intro.mp4 -acodec mp3 intro.mp3

I used audacity to clip and clean up a sample, including re-sampling it at 8kHz and exporting as a WAAV file saar_from_boldport.wav.

Finally, I used the sample_encoder.rb Ruby script to convert the WAV file into the sample_saar_from_boldport.h header file which is used by the CuttleTalk.ino sketch loaded on the Cuttle.

ruby sample_encoder.rb sounds/saar_from_boldport.wav > sample_saar_from_boldport.h

Construction

The LiFi broadcast is simply a Cuttle with a high-intensity white LED on pin 11/PB3 and a 220Ω current limiting resistor:

Credits and References

• LEAP#419 lite2sound-bc - main lite2sound-bc project
• LEAP#210 TDA7297 Kit
• LEAP#417 SimpleSamplePlayer
• node-ytdl - A youtube downloader written in Javascript
• ffmpeg
• audacity
• ..as mentioned on my blog