~ Doorbell triggered Halloween window projection

Fig: Door projection as imagined by DALL.E.

I did a thing, and, similar to most stuff made here, it is quite a bit of effort and rather pointless. In that sense, it is a bit like life itself. Anyhow, it seems that the Halloween tradition of trick-or-treating has found a strong foothold in mainland Europe. Due to social embeddedness, I prepared Halloween themed projection that responds to my door-bell. I have a glass door, which is ideal for scary projections. The idea is to have a continuous door projection but with a twist: when kids press the doorbell a projected ghost reacts and rushes towards them along with a loud ghostly scream.

This blog post details the technical setup with the intention to inspire similar projects and serve as documentation for next year. First we need a way react to the doorbell.

Doorbell trigger setup

I sourced a couple of FSR‘s from a “sound book” that I had taken apart. Most of these sound books with e.g. animal sounds are meant for toddlers and have a some type of button and a small electronics circuit to make sound. Some of these books work with FSR ’buttons’ which are similar in size to a doorbell. I took a single FSR from such a book.

I attached the FSR to a “Teensy LC” micro-controller with an additional resistor and put it in a small 3D-printed case. The Teensy was programmed to emit a MIDI Note On event when the FSR/doorbell is pressed. A Note Off follows when the button is released. Once it is connected via USB to a computer it is essentially regarded as a digital piano with only a single key. Making a micro-controller pretend to be a standard MIDI device is very practical since the message passing protocol is standardized and well supported by many types of systems. MIDI is also optimized for low-latency communication. Via the Web MIDI API there is even support for MIDI in web browsers.

Video projection

While software like Resolume allows for complex interactive video projections, my requirements are more modest: I need a continuous background video and I want the ‘scare’ video and audio to appear when the doorbell is triggered. I opted for a browser-based solution: multi-media capabilities, scripting and MIDI support are all present in modern browsers. Running things in a browser has advantages: there is no need for specialized software, it is easy to program, easy to run, relatively stable and future-proof. The proof-of-concept can be seen below. For the actual projection on a window or door you need to first cover the glass with a thin layer of white paper which lets most light through. A white paper tablecloth works well.

The code is not much special and a bit hacky but can be found attached. The download includes the “html, javascript, css, video, audio and the micro-controller software for a doorbell-triggered projection”.

0110.be and UGent

~ Started at the Ghent Centre for Digital Humanities

Fig: Gent Gemapt, an recent GhentCDH project.

From the first of October I started at the Ghent Centre for Digital Humanities as research software engineer. GhentCDH " engages in the field of ‘Digital Humanities’ at Ghent University, ranging from archaeology and geography to linguistics and cultural studies. GhentCDH develops DH collaboration and supports research projects, teaching activities and infrastructure projects across the faculties".

I will be helping with the many projects they are involved in: ranging form public research valorization to internal research tools. I am sure I will learn a lot by discussing projects with a diverse range of researchers and hope to consolidate my expertise in the area of mulitimedia analysis and annotation in some ways. The current areas of expertise can be found on their website:

• Collaborative databases: offering advice and support for collaborative databases at Ghent University. It helps researchers to develop a database instance, powered by e.g. Nodegoat. It provides advice regarding data standards and linked data.
• Digital text analysis: aiming to improve digital text analysis at Ghent University by offering support and information to researchers. You can contact us for advice on TEI and digital editions, working with digital text analysis tools, and using computer-assisted qualitative data analysis.
• Geospatial analysis: offering advice, support and training regarding geospatial data management, analysis and visualisation to the humanities and social sciences researchers at the Ghent University.
• Digital heritage: offering support in regards to digital heritage, participation and virtual expositions. GhentCDH helps researchers, teachers and students to create, manage and enrich their own digital collections and set up virtual exhibitions around them.

A recent GhentCDH project is Gent Gemapt or Ghent mapped ‘an interatcive platform which connects places, historical maps and heritage collections which each other and the wider audience’.

UGent