Spice up Raspbian for the IoT

Spice up Raspbian for the IoT

Overview

Using the basic WPAN enabled Raspbian image we created using the first guide, we now want to add some software and convenience functionality to use the Pi in IoT projects. That means to init a 6LoWPAN device on system startup and add support for common IoT protocols to Raspbian.

Install useful tools and packages

• useful tools when using the terminal

sudo apt install vim screen htop cmake

• some Python add ons

sudo apt install virtualenv python-all-dev python-pip python3-pip

Systemd lowpan

Wouldn't it be nice to have your 6LoWPAN network interface up and running right on system boot? Unfortunately, wpan integration is not fully functionally so you cannot setup these devices using /etc/network/interfaces like for your other ethernet or wlan interfaces such as eth0 or wlan0. However, with a little work around providing some helper scripts and a system service definition you can achieve the same. Proceed as follows:

• first clone this repository

sudo mkdir -p /opt/src
sudo chown pi /opt/src
cd /opt/src
git clone https://github.com/riot-makers/wpan-raspbian
cd wpan-raspbian

• next copy some helper (shell) scripts to a well-known location:

sudo cp -r usr/local/sbin/* /usr/local/sbin/.
sudo chmod +x /usr/local/sbin/*

• afterwards copy files for systemd integration

sudo cp etc/default/lowpan /etc/default/.
sudo cp etc/systemd/system/lowpan.service /etc/systemd/system/.

• modify channel and pan id in /etc/default/lowpan as needed
• optional you can also set the MAC/LLADDR of the lowpan interface, it changes with every boot on default
• and finally activate the low pan autostart in systemd

sudo systemctl enable lowpan.service

• you can check if everything works as expected by running

sudo systemctl start lowpan.service
ip link
# ^^^^ you should see a lowpan0 device, and wpan0
sudo systemctl stop lowpan.service
ip link
# ^^^^ lowpan0 device should be gone, only wpan0 

• have a look at the README for details

COAP support

COAP is one of the major protocols for the Internet of Things, simply said it implements a HTTP-like protocol to query sensors that provide a RESTful interface. For further information on COAP see here and if you want to use COAP for development or testing you may want to install one of the following libraries and tools.

C/C++: libcoap

• clone libcoap from Github

$ cd /opt/src
$ git clone https://github.com/obgm/libcoap.git

• configure and build

$ cd /opt/src/libcoap
$ ./autogen.sh
$ ./configure --disable-documentation
$ make
$ sudo make install

• we disable documentation, because otherwise you'll have to install >2GB of dependencies
• Note: libcoap comes with a nice tool for testing named coap-client, so if you have a sensor node with a 802.15.4 transceiver that uses for instance RIOT-OS with microcoap you can query that node.
• to run coap-client you have to update the dynamic linker cache before:

sudo ldconfig -f /etc/ld.so.conf
coap-client -m GET coap://[ff02::1]/.well-known/core

Python2: txThings

• install txThings using pip2:

sudo pip2 install txThings

Python3: aiocoap

• install aiocoap using pip3:

sudo pip3 install aiocoap