Week 6 | Untoolkit - Electronic inputs

This week, I am working with Desiree van Dam on a project with an Arduino Uno. We will make some digital and analog sensors.

Because of the corona virus the school was closed. I visited desiree for a day to work together on the assignment. Then we continued at home.

We divided the tasks. This week I focused on the digital switch and Desiree on the analog.

Since I was sick the week before, I had not been able to get a breadboard and I could not immediately test my sensors. I caught up with this in week 8 (the output week) after I ordered a breadboard.

First some theory

A sensor is an electronic device that is constantly measuring a physic variable. For example: temperature, distance, humidity, light, etc. And then transforms the physic variable in an electric signal. An actuator is an electronic device that transforms an electric signal in a physic variable (light, sound, etc.)

They are two kinds of sensors: digital and analog.

A digital sensor only detects two possible status: if it is working at 100% or at 0%.

An analog sensor measures continuously the variable and detects any proportional value between 100% and 0%. For this reason, the measure provided by the analog sensor is more precise than the one provided by the digital sensor. source: https://www.ksixmobile.com/en/post/difference-between-analog-and-digital-sensors-167.php & lessons in class

The process

Desiree and I made four analog sensors. Their all based on the following sensor which was given as a example.

This 'switch-sensor' is made of a bead that hangs on a cardboard by means of a piece of steel, copper tape and conductive wire.

When you move the cardboard back and forth, you switch the circuit on and off: you break the circuit and you close it.

By connecting this properly to the Arduino Uno, you can operate an LED light.

The following four sensors are made by Desiree and me. We used this example as inspiration.

Sensor one

This first sensor, looks a lot like the one above. The difference is that the ball in the middle is not a bead, but a marble. Also, we did'nt use the solder device. But in big lines, it's the same.

The difficult thing about this was that we had no beads. A bead has a hole in the middle where you can easily put the copper wire through and fasten it like this. With a marble it is quite a job to attach this to a copper wire because it keeps slipping or is not firmly attached.

Sensor two

The second sensor is also a hanging marble. Here, I have made the points that the marble should touch, higher (the soft balls).

As you may can see, I used copper wire to tie the copper tape to the soft ball. When I tested this on my Arduino of Desiree, it didn't work. Then, I used another wire that worked in my previous sensor, this worked immediatly. The other copper wire was not a good conductor.

Sensor three

The third sensor works also like the two before: tilting the paper to let the marble move, but here, the marble doesn't hang. With a hole in the middle the marble can move.

The marble is with a wire conneced to another marble on the other side. This ensures that the marble remains in the right place.

If you tilt it left or right, the marble will touch the copper tape and close the circuit.

Sensor four

This is the last sensor. The marble is connected to two wires which meet eachother on the back of the sensor. The idea was to role the marble to the other side.

So, after making these four switch sensors, I wasn't able to connect them immedietly to the Arduino because I didn't have a breadboard. In the 8th week my breadboard came and I tested the sensors below.

Connecting to the Arduino

The paperclipwires we soldered together in class were all still at Desiree place. I don't have a soldering machine at home, but this was not that necessary. I still attached the wires to the sensors with a paperclip. It was annoying that they detach very quickly when I moved the Arduino.

I used the setup of the breadboard from the video that Loes had put on DLO. No code was included, I used the Arduino to make it a circuit and to use the power.

Reflection

I am happy that all sensors worked without having to change anything. However, I had wanted to take velostat and copper wire from the Makers Lab for myself afterwards, so that I could also experiment with analog sensors. On the other hand, I would have had less time for other things if I had.

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