---
tags: mdef, fablab
---

# Measuring the world - Tools Demos

[toc]

## Individual data capture

### SCK


:::info
**DEMO:** https://hackmd.io/@oscgonfer/rkcvFgjxL
**DOCS:** https://docs.smartcitizen.me
:::

### Images

Using [motion detection](https://en.wikipedia.org/wiki/Motion_detection) technics or a simple [timelapse](https://en.wikipedia.org/wiki/Time-lapse_photography) you can get a lot of information on what's happening around you. A sequence of images can give you information on the number of persons, the color of cars, the size of dogs or any other subject of interest for your research.


#### Smart phone

Smart phones are filled with sensors, they can capture all kind of data and probably you will find a good quality camera. You should plan your capture periods, locations and frequency depending on what information you want to get from the images.

There is a lot of applications to record timelapses, [TimeLapseCam](https://github.com/woheller69/timelapsecamera) is open source app that can record time lapses with the screen off. You can also use motion detection to only get images when something is happening there is a lot of apps that can detect motion and trigger the capture.


If images don't give you answers, you still can use your phone, try experimenting with [Phyphox](https://phyphox.org/), it allows recording data from most of your phone sensors, export it, and even control the capture from a web browser.

#### Pi Camera

 

Using a [Raspberry Pi](https://en.wikipedia.org/wiki/Raspberry_Pi) SBC computer and a camera allow us to grab images in a simple and inexpensive way.

First install a [Raspbian](https://www.raspberrypi.org/downloads.../) system on your sd card, you can follow this [tutorial](https://raspberrytips.com/install-camera-raspberry-pi/), be sure to reach the point where you enable and test the camera.

Now we can install a [Web Interface](https://elinux.org/RPi-Cam-Web-Interface) to manage the camera, detect motion or record timelapses. You just need to follow the _Installation Instructions_ until step 6.

If everything went OK when you open your computer browser and point to the Raspberry Pi IP address (eg http://172.16.23.21/html) you should see something like this:

You can check the [usage](https://elinux.org/RPi-Cam-Web-Interface#Usage) documentation to configure your camera to save a timelapse or record videos when motion is detected.

*[SBC]: Single Board Computer

### Physical intervention

Plan a data collection interface using digital fabrications techniques from the Fab Lab, like so:


### (B)arduino Sensor

Below there is an example of how you can use a simple sensor. However, you can use your B(arduino) if you like.

> A photoresistor (also known as a light-dependent resistor, LDR, or photo-conductive cell) is a passive component that decreases resistance with respect to receiving luminosity (light) on the component's sensitive surface.

 

Example code that will output LDR value 20 times a second (20Hz) via USB Serial port.
~~~clike
int sensorPin = A0;
int sensorValue = 0;

void setup() {
Serial.begin(115200);
}

void loop() {
sensorValue = analogRead(sensorPin);
Serial.println(sensorValue);
delay(50);
}
~~~

You can use the Arduino IDE _Serial plotter_ to see the changes in real time:


To capture the data to a file for latter processing, in OSX and Linux you can do

~~~bash
stty -F /dev/ttyACM0 raw 115200
cat /dev/ttyACM0 > data.csv
~~~

Other option is installing [this](https://circuitjournal.com/arduino-serial-to-spreadsheet) tool that allows you to capture directly to a CSV file and even include timestamps.


### GPS Mobile location

Get **[GPS Logger for Android](https://gpslogger.app/)** or similar app to save location data to a gpx file.

1. Select the file format in "recording details"


2. Send them to your laptop by simply sharing the file
3. You can then view your GPX files in a program like https://www.gpxsee.org/


## Collective data capture

### Web Scrapping

:::info
Check the notes here: https://hackmd.io/@vico/By0CXMHk3
:::