Boltanski Prendre la parole V1

Jan Enning
Jul 8 · 5 min read

A year ago we were asked to build this installation for the Oude Kerk in Amsterdam. This installation from Christian Boltanski had a sensor which, when triggered, will play an audio file. The light will always be on. The sensor was battery powered, the light was using mains voltage (220v).

We had to tackle 3 problems;

  • Maintenance personnel needed to check if the sensor was still working and if the batteries were still charged.
  • And get rid of mains voltage. This due to fact that the Oude Kerk was build out of wood, just like Notre-Dame — Paris.
  • Easy way of adding sound files.


Layout of the components we need: Speaker, Arduino Pro mini, led driver, Sonic rangefinder, DFplayer and an optional potentiometer


Function layout

  • When a user walked between 80 Cm ~ 130 Cm the sensored needed to trigger
  • Then an audio file needed to play
  • Meanwhile the sensor would not pick up a trigger
  • When the file was finished playing the sensor was disabled for 30 Seconds
  • After that the system was primed again for a new trigger.

PCB hacking



Units getting ready
20 units ready
Stock case with laser cut holes

What we needed to do differently

Do not use an Ultrasonic sensor

A faulty ultrasonic sensor; upper cone came loose due to temperature differences.
On the back of the cone you see a tiny bit of glue. It would not soften when I heated it. But the glue did not hold its rigidity when exposed to cold and moisture.


Troubling case


PCB design


What went good

What went even better

Jan Enning

Written by

Frontend developer with a soldering iron