For beginners: Switch a light on with the payment of IOTAs using a Raspberry Pi
This article is based on the instructions written by Hugo Gregersen: Integrating physical devices with IOTA. I was not able to get things working according to his instructions so I started trying until I got it working. Please let me know if you see anything that needs improvement.
1. Hardware Setup
1.1 Components
- Raspberry Pi 3 (or 2) with the following components: WiFi, 32GB Micro SD card, Power supply.
- 1 Channel DC 5V Relay Switch Board Module for Arduino Raspberry Pi ARM AVR
- 3mm 5mm LED Light White Red Green Yellow Assorted Emitting Diode DIY Set
- Breadboard
- 330 Ohm resistor
- Breadboard wires (F/M and M/M)
- 9V Battery
In addition, you will need for the setup: USB keyboard, USB mouse and HDMI cable.
1.2 Assembly
Look carefully at the diagram.
- The LED has two legs. The shorter leg has to be on the side of the resistor.
- The output side of the relay decides the on/off operation. If the orange cable is connected to the bottom, then it is OFF/ON. If you connect the orange cable to the upper slot the operation will be ON/OFF.
- Once you turned on the Raspberry, the red light on the relay should be on
2. Software setup
On your computer do the following:
- Download and install SD card formater on your computer: https://www.sdcard.org and format the SD card.
- Download Raspbian (NOOBS): https://www.raspberrypi.org/downloads/noobs/ . You can download NOOBS lite.
- Copy the NOOB content to the micro SD card (only copy the content inside the downloaded folder and not the folder itself).
Remove the micro SD card from your computer and insert it into the Raspberry Pi.
Connect to the Raspberry Pi:
- Monitor using the HDMI cable
- Mouse and keyboard
- Power cable
Power up the Raspberry Pi and install the full version of Raspbian.
After reboot, select menu →Preferences → Raspberry Pi configuration, then select tab Interfaces and enable: SSH, SPI and VNC.
If you prefer to connect remotely to the Raspberry Pi perform the following steps:
On the Raspberry open the terminal and use the following codes:
sudo apt-get update
sudo apt-get install realvnc-vnc-server realvnc-vnc-viewer
To get the raspberry Pi ip address (for example 192.168.1.20), type in the terminal: ifconfig
Reboot the Raspberry Pi:
sudo reboot
On your computer download the VNC viewer: https://www.realvnc.com/en/connect/download/viewer/ and follow the instructions.
Once installed use the Raspberry Pi IP address as well as username and password to log into your Raspberry.
3. Installation of Python
1. Ensure your Raspberry Pi is running the latest version of all the software. Run the following two commands on your Raspberry Pi to update it.
sudo apt-get update
sudo apt-get upgrade
2. Install the python2.7-dev package
sudo apt-get install python2.7-dev
4. Testing the light
Let us test if the installation was so far successful.
Open the terminal on the Raspberry
sudo nano light.py
and insert the following code:
https://medium.com/media/37966f0d6ba44e0711a7d42311f5d6e9/href
To save the file press Ctrl + X then press Y and then press Enter.
Now run this program:
sudo python light.py
You will hear the relay clicking and the green light on the relay turning on and off. If the LED is not turning on you most likely will have the cables to the battery wired wrong.
4. Activate IOTA
To communicate with the IOTA tangle you need to install the PyOTA library (https://github.com/iotaledger/iota.lib.py):
cd ~/
sudo apt-get install libffi-dev (to avoid the error: “failed building wheel for cryptography”)
sudo pip install pyota[ccurl]
git clone https://github.com/iotaledger/iota.lib.py.git
To test if the installation was successful (this will take around 10 minutes):
cd iota.lib.py
python setup.py test
