Hardware

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Github Links:

Planted Github | Back End | Front End

Components

Single Board Computers and Microcontrollers

• Raspberry Pi 3 model B
• Arduino Uno

Sensors

• OSEPP Humidity and Temperature Sensor - HUMI-01
• Generic photo resistor

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Setup

• Download Arduino IDE from here.

  The IDE allows for easy uploading of programs to the Arduino via USB

• Prepare the Raspberry PI.

  • Download Raspbian from here.

  Raspbian is an Debian based version of Linux optimized for the Raspberry Pi hardware.

  • Write the Raspbian image to a microSD card

  A good tool to write the image for Mac OS is Etcher

  • Plug Pi up to a monitor, keyboard, and power.
  • Initially username will be 'pi' and password will be 'raspberry'
  • Setting up wifi for the Pi

  From the console we can scan for wifi networks using iwlist

pi@raspberrypi:~$ sudo iwlist wlan0 scan

This will output quite alot of information on local wifi networks, pay attention to the ESSID values they are the names of the wifi networks. Then we will add the network information to the 'wpa_supplicant.conf' file

pi@raspberrypi:~$ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

We should be able to go to the bottom of this file and add

network={
    ssid='essid name from earlier'
    psk='the password for the network'
}

Sometimes a wpa_supplicant.conf file can be placed in the boot partition of the memory card to get connected to wifi.

To check if wirless is working use this command.

pi@raspberrypi:~$ ifconfig wlan0

If the inet addr field has an address beside it.

To restart wireless if it does not automatically these commands can be used.

pi@raspberrypi:~$ sudo ifdown wlan0
pi@raspberrypi:~$ sudo ifup wlan0

Circuit

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Goal

Collect data from a variety of sensors. The Arduino is used because it can deal with both analog and digital sensors. The Arduino simply reads data from the sensors at a set time interval and then transmits this data through serial communication to a Raspberry Pi. The Pi takes this data, puts it into JSON form, and sends it through POST requests to a server deployed on Heroku.