Internship at Entry Engineering: the first step towards an interactive artifact for the InterBridge exhibition

When we (note: Víťa Kříž and Lukáš Prokop) entered the premises of Entry Engineering in Mladá Boleslav at the end of October as interns for the InterBridge project, we had no idea what awaited us – but we knew that we were entering a period when our project was entering its final year and was newly focusing on mechanical engineering, electrical engineering and programming.

We started our internship on Wednesday, October 29th at the Entry Engineering branch at Koněvova 350, where a signing ceremony took place – a contract and a non-disclosure agreement (NDA) with the help of Ms. Karolína Hušková from the HR department. After the initial formalities, we took our box of components and moved to Vodkova 84/10, where the company’s workshop is located in Mladá Boleslav. On site, we were assigned two colleagues from Entry, Rostislav Janda and Marek Žanta, who guided us around the workshop, helped with technical details and supervised our work. They welcomed us in a laboratory equipped with oscilloscopes, power supplies, soldering stations… and so we unpacked the first hardware from our box of components and got to work. Our task during the internship was to use the experience and cooperation with Entry Engineering – as well as with partners in Germany – and develop a so-called interactive artifact, which will be part of our exhibition at the end of the 3rd stage of the InterBridge project. This artifact will allow you to blow into the device (yes, that is the intention) and measure the properties of breath – temperature, humidity, CO₂ content, ethanol and other parameters. So we had to assemble, model and program.

The Entry Engineering company in Mladá Boleslav has a strong focus on the automotive industry – development and testing of functions, components and HW/SW for cars – which provided us with an ideal technological background. Colleagues from Chemnitz University of Technology led by Dhivakar Rajendran from the Department of Measurement and Sensor Technology also joined the activity. His research deals, among other things, with very thin piezoresistive pressure sensors, so he is a completely competent collaborator for our purpose. As part of the collaboration, he helps us with the design of the sensor part of the artifact - especially where it is necessary to convert physical quantities into digital form and ensure reliable measurement of breath properties.

First days in the Entry workshop

First, we loaded the operating system into our Raspberry Pi 5 - instead of the classic RPiOS, we chose Ubuntu. SD card readers, soldering irons, oscilloscopes and other equipment were available. The installation required connecting a monitor, keyboard and mouse - and here was the first hitch, because the monitor had micro-HDMI, so we had to buy a reduction. After installing Python and creating the "InterBridge" user who had access to the GPIO pins, we connected the first sensor "breadboard" assembly - temperature and humidity. We connected via SSH and wrote the first test programs to verify that the data was actually coming in. When we tested other sensors (e.g. CO₂ or ethanol), we found out that they were analog – and therefore needed a converter. In the meantime, the company lent us an Arduino, which has analog pins. At the same time, we worked on the boxes: I cut holes and solved the problem of attaching the tube for the “blower”, Lukáš prepared a 3D model of the housing for the Raspberry Pi – and we immediately printed the first version on the 3D printer. This also brought trigonometry (precise measurements and angles) into play.

Finally, we attached the garden hose connector to the box – the tube holds and serves its purpose. Lukáš was a little disappointed that 3D printing was not necessary in the end, but the solution works. During the assembly, we discovered that we were missing some components – fans (USB) due to water condensation, converters and cooling. In the future, we will be drilling more holes, testing transducers, more sensors, connecting fans and completely assembling everything into one functional unit.

In conclusion

This internship is a big step for us: we are combining technology (sensors, programming, mechanics), mechanical engineering and electrical engineering - an area that the InterBridge project is entering in its final phase. After 2025, when we focused more on fashion, textiles, glass and jewelry in cooperation with Preciosa, we are now moving towards "harder" technology. The result we are currently working on will be an interactive object for the exhibition - visitors will be able to blow into it and watch how the measured values ​​(temperature, humidity, CO₂, ethanol) are transformed into a creative visualization on the screen.

Thanks to the cooperation with Entry Engineering, the technological background and the support from the German academic laboratory, we have a very good foundation - although there is still a lot of work ahead of us. We are currently in the prototype phase, but we believe that the final exhibit at the exhibition will be truly interactive and functional. We leave this internship with a good feeling – and also with the knowledge that we have a concrete and challenging journey ahead of us. The combination of technology, creativity and international cooperation describes what InterBridge is all about.

Vítězslav Kříž