Hackathon Spain 2023

Team Macrohard ™ – illuminating a bridge in a spanish forest

Our case

The company Interlight introduced us to a case in a spanish park. In this park, there is a bridge that is currently not illuminated which makes it really difficult and dangerous for people to cross it when it is dark outside. We were given the following criteria for illuminating the bridge:

  • The light should only illuminate the bridge and not other parts of the park so that it doesn’t disturb the wild life
  • The light should only turn on when it is dark outside
  • The color of the light should change according to the ambient temperature – blue when it is warm outside and red when it is cold
  • The light should only be on when necessary – when no people are nearby, it is not needed

Our group

Andrii 🇺🇦, Jose 🇪🇸, Toni 🇪🇸, Enrico 🇪🇸, Jakob 🇩🇪

Our other idea

Window sensor for A/C

A lot of times, people use their air conditioning while their window is open. This leads to high power usage which is bad for the environment and can get expensive really fast. So, we thought about creating a sensor that is connected to the air conditioning so that it only turns on when the window is closed.

The target groups for our project

Persona 1:

Name: Segismundo Ramírez Tormes
Age: 85 years
Behaviour: likes going for short walks in a park and looking for animals. A safe path is important so that they don’t trip or get hurt
Pain points/frustrations: bad vision, can’t see well in the dark and feels unsafe when it turns dark early, especially in winter. So the bad visibility of the bridge gets in the way of a walk in the park
Needs/goals: Need a way to see the bridge and the path better in order to do safer walks
Persona 2:
NameJoaquín Banderas Herrero
Age10 years
Behaviour: likes playing in the park, running around and looking for animals and interesting stuff
Pain points/frustrations: parents are scared when child is out in the dark, child is scared of the dark
Needs/Goals: a safer park where the child can see a lot better which makes the parents feel a lot safer about letting him out alone/with friends

Our prototype

We started by connecting the first few modules as some of us have never worked with an Arduino before.

After that, we connected more and more modules until we connected everything we wanted to have in our final prototype.

On top of that, the code slowly came together:

For our prototype, we 3D printed a small bridge for showing how we wanted to connect the LED strip

Future extensions for the project


As we won’t be able to always have a laptop or a power outlet connected to the LED strips, we thought about multiple ways to power the solution:

  • A solar powerbank
    • if the park has got enough sunlight, we could connect a powerbank with solar plates to the LED strip. By this we can use the sun to charge everything up in the day and then use the powerbank at night
  • A wind turbine
    • If the park has got enough wind, we could use a small wind turbine to charge up a powerbank and the power the LED strip and Arduino for times without wind. This solution is heavily dependent on the location of the bridge, because too many trees might block the necessary wind.
  • A water turbine
    • As the bridge is going over a river, there is a constant flow of water below it. If this doesn’t disturb the wildlife, we could build a small water turbine in the water and connect it to the LED strip. This would eliminate the need for a powerbank, as the water won’t stop flowing in the forseeable future.
  • Connecting the system to the park power system
    • In the case we don’t get to work with any type of renewable energy, we could connect it to the parks power supply, as there already are lights and our system just requieres a 5v and a 12v exit


  • In the daylight, we can use the power for a screen that shows useful information about the park and its wildlife. It could show, what kinds of animals are currently outside or what plants you can find. On top of that, we could show some information about the ambient temperature and other air quality measurements.


  • In order to make the bridge more accessible, we thought about some solution for helping blind people with navigating the bridge. For this, we would need to play some kind of sound, but we would have to check how we don’t disturb the wildlife with this solution.


  • If something goes wrong with the LED strip, we would need some way of noticing that. One solution we thought of was to put a SIM card into our Arduino which can send out an SMS if any errors occur. If there is internet at the bridge, we could also use an LTE SIM card and then create a live dashboard with all the data that the sensors collect.

Empathy map canvas

Lessons learned

  • Identifying a problem and finding the solution for it
  • Working with an Arduino
  • Always make Siesta

The end result