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Tag Archives: raspberrypi

MagicMirror2 and Chuvash

This post is about my setup of the popular MagicMirror2 application. I show the steps needed to set it up on a Raspberry Pi Zero W and connect it to a TV set. As a bonus, I share my thoughts on the Chuvash localization work.

MagicMirror2 is a DIY project and an open-source application, voted to number one of the best Raspberry Pi Projects. In essence, it shows information of your choice (weather, calendar, news) on a screen that is embedded in a mirror.

I was introduced to MagicMirror2 by my colleague, who uses it in another way: rather than having it in a mirror, he has it on his smart tv. The customisability is the beauty of the whole DIY and the Raspberry Pi.

Installation

I also decided to use it on my tv, through the built-in web browser. My raspberry pi zero w required some special steps due to its processor architecture. Fortunately, I found a guide for MagicMirror2 and Raspberry Pi Zero W which I used as a starting point.

After trying it, I found that I needed those steps for my server-only magic:

  • Install node and npm for armv6l
  • Clone the MagicMirror
  • Install npm packages targeting the armv7l
  • Run the server
# node from apt won't work
wget https://nodejs.org/dist/v10.16.0/node-v10.16.0-linux-armv6l.tar.xz
tar xvf node-v10.16.0-linux-armv6l.tar.xz
cd node-v10.16.0-linux-armv6l/
sudo cp -R * /usr/local/
sudo reboot
git clone https://github.com/MichMich/MagicMirror
cd MagicMirror
# it needs to be armv7l, not armv6l
npm install -arch=armv7l
# if errors arise: rm -rf nod_modules. Then npm install again
npm run server .
view raw magicmirror.sh hosted with ❤ by GitHub
Creating a bookmark on the TV browser.

My tv screen with MagicMirror2 localized into Chuvash

Chuvash

Every time I work with software I try to think: can I help to translate/localize it to Chuvash. Chuvash is a “little” language, it is only spoken by 1.5 million people. Almost in all cases, it is hard to even to register the Chuvash as such (like in Windows, or macOS), and it is even harder to localize applications, because they tend to have thousands or sometimes millions of strings to translate (and maintain!).

With MagicMirror I experienced how work from the past can help today, how small pieces can become connected parts of a bigger picture.

MagicMirror uses momentjs, a javascript library for datetime. In matter of fact, that’s exactly something that I already have worked on:

That was nice! I changed language to “cv” in the config/config.js and the most of the interface turned into Chuvash. (cv – is the iso code for Chuvash language). What a feeling of joy!

Why that excitement? Well, almost everything in the Chuvash IT (UX, localization, keyboard layouts, speech recognition, machine translation etc) is driven and sponsored by volunteers and a community. That’s why it is a special joy to see pieces come together, even though it is a small DIY project.

The MagicMirror2 itself does a minimal set of strings to translate. I translated it and submitted a Pull Request, which has been already merged to the develop branch.

I also created a list of Compliments in Chuvash and submitted it as a Pull Request.

DIY: Integrating Trådfri lights with Teams presence

It seems that Work from Home (WFH) is here to stay, it’s okay. I’d say, Work from a Smart Home is even more okay. To me, Home Automation (HA) and Work from Home (WFH) are really two peas in a pod.

Today’s “guest” is a tiny application that I’ve set up on my raspberry pi to listen to my presence (status) in Teams and show it with colors of my smart RGB light (IKEA Trådfri).

The code

You can find the application on github:

I’ll try to provide the needed documentation on the github repo and focus more on the story part in this blog post.

The story

I stumbled upon Elio Struyf’s blog post and I was amazed:

Wow! I thought immediately: that would be a cool challenge, I wanted to set up this, too. Although, with some adjustments for my smart home:

  • I wanted to run the whole application on one raspberry pi only, because I don’t have the second one, neither I have HomeBridge installation (maybe something for future projects, though).
  • I wanted to have as little code as possible, maintenance should be kept to minimal.
  • I wanted to use python in order to learn more python and because python seems to be the most supported language on the pi.
  • I wanted to use IKEA Trådfri lights (with a gateway and a remote) that I already have invested into.

I omit the configuration steps for Trådfri lights and Raspberry Pi, you can see them in my previous blog post:

Why show Teams presence with a smart light

Elio wrote his blog post in April this year – in the times of the lockdown in Belgium. In Sweden, we hadn’t a real lockdown, but it seems that it might come times when my children would need to be at home more while I work. In that case a superclear system that shows when I have important meetings is just awesome. Maybe, with that I am prepared for such times.

But to be really honest, the main driving factor is the fact that it is very satisfying to tinker around with this DIY stuff 😜😎

Lessons learned

There is a python wrapper for MSGraph which is awesome, but it needs more contributors:

In your Azure AD App Registration you can specify auth flow type as public, with that you don’t need to store a client secret for delegated access. That was a kind of a new thing to me.

Presence endpoint in MSGraph is in beta, make sure you call the beta endpoint. The scope is ‘https://graph.microsoft.com/Presence.Read’ and you need an admin consent for that permission grant.

Flashing Trådfri lights on Azure Alerts

What if you put together Work From Home and Home Automation? Well, removing the common denominator (HOME) would mean Work Automation (sic!). I want to tell you about a tiny hobby project I have had at home, still related to work of mine: Whenever an Azure alert is triggered, my Trådfri smart light from IKEA flashes for a couple of seconds.

Summary (if you want to skip the long story below): The solution is a tiny web application. The publicly accessible url, exposed using ngrok, is registered as a webhook in an Azure Alert. It’s on Github, you’re welcome to use it as you please 😎:

How I did this (the long story)

The github repo (linked above) is self-expaining, but here comes the story. I used the same setup for Azure Alerts as described in my previous blog post:

When I was done setting up an alert, I thought: besides a notification in a Teams channel, I thought: what if I could show the alert visually using some LED or similar? Then I thought about Home Automation and a Trådfri RGB bulb I’ve got. That’s the beauty of the mentioned equation: Work From Home and Home Automation. We can pick the best parts of it and combine to something unique.

Since I have a kit from IKEA containing a gateway, a remote, and an RGB lamp, I wanted to do something with that. Unfortunately I didn’t find any routines (Google Home), applets (IFTTT) or automations (Home app in iOS) that could do it.

Luckily, there is a way of controlling the Trådfri lights, best described in this tutorial:

As in this tutorial I also used a Raspberry Pi Zero W, and it went very well, except one thing: Trådfri team introduced a change for the security code, I needed an additional step that was missing, more on that later.

The flow from an Azure Alert to the flashing light.

The tutorial says: the world is your lobster. My “lobster” is a webhook that makes lights flash on an alert, so I needed to have a simple web server (http.server) and a tunnel to my network (ngrok). It was best to take one step at a time.

Step 1. Connect

First, I wanted to make sure I could have a simple web server that could host my webhook. I followed the advice from that tutorial and used http.server python module:

I didn’t need to install any additional modules, you have this already on the Raspberry Pi OS. Just create a simple file like this:

from http.server import BaseHTTPRequestHandler, HTTPServer
host_name = '192.168.0.193'
host_port = 8000
class MyServer(BaseHTTPRequestHandler):
def do_HEAD(self):
self.send_response(200)
self.send_header('Content-Type', 'text/html')
self.end_headers()
def do_GET(self):
self.do_HEAD()
self.wfile.write("hej".encode("utf-8"))
if __name__ == '__main__':
http_server = HTTPServer((host_name, host_port), MyServer)
print("Server Starts – %s:%s" % (host_name, host_port))
try:
http_server.serve_forever()
except KeyboardInterrupt:
http_server.server_close()

Start it:

python3 alert-step1-server.py
view raw alert-step1-start.sh hosted with ❤ by GitHub

I opened that page, (192.168.0.193:8000), and I could see “hej”, time to go further.

Step 2. Connect World

Next step was to open up this “web app” for the world, to make it accessible from outside my local network. ngrok is the best solution for that. I followed that guide to install ngrok on my Raspberry Pi Zero W.

The installation process was pretty straight forward, for the record I tried to install ngrok as a snap, it did not work.

cd ~
wget https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-arm.tgz
tar -xvzf ngrok-stable-linux-arm.tgz
view raw alert-step2-ngrok.sh hosted with ❤ by GitHub

I also fetched the authtoken and registered it locally

Then I started the ngrok tunnel:

And my web app went online:

Step 3. Harness the lights

Now to the core of this hobby solution: controlling Trådfri lights.

I installed, configured and built the libcoap client, as described in the blog post I already mentioned:

But I also installed git, because my Raspberry Pi OS installation didn’t have it.

sudo apt-get install build-essential autoconf automake libtool git -y
git clone –recursive https://github.com/obgm/libcoap.git
cd libcoap
git checkout dtls
git submodule update –init –recursive
./autogen.sh
./configure –disable-documentation –disable-shared
make
sudo make install

Next, I found the IP Address and the security code of the IKEA Trådfri Gateway, using my router:

Then I created a new preshared key (that’s the news I mentioned above). With just the security code, you will get 4.01 “Unauthorized” when you try to control the lights, as described:

# -k = Security Code, that you can find on the back of the gateway
# 9090: xxx, your new client identity, you decide, in my case TOLLERASP0
# coaps: the ip address is the one of your gateway
coap-client -m post -u "Client_identity" -k "OHsfKxV0UaJu81" -e '{"9090":"TOLLERASP0"}' "coaps://192.168.0.120:5684/15011/9063"

I got the pre-shared key that I saved for later use:

With this information you can harness the IKEA lights:

# off
coap-client -m put -u "TOLLERASP0" -k "{presharedkey}" -e '{ "3311": [{ "5850": 0 }] }' "coaps://192.168.0.120:5684/15001/65537"
# on
coap-client -m put -u "TOLLERASP0" -k "{presharedkey}" -e '{ "3311": [{ "5850": 1 }] }' "coaps://192.168.0.120:5684/15001/65537"
view raw alert-step3-onoff.sh hosted with ❤ by GitHub

5850:0 is off, 5850:1 is on. Easy-peasy, right?

Want to know how to control the brightness, the colors etc, just check this documentation (already mentioned):

Step 4. Put everything together

When I knew I could have a simple webhook service, locally (step 1) and on the WWW (step 2), and that I could control the smart light I’ve got from IKEA using code running on my raspberry pi, then connecting everything was easy. I created a repo for that and you can see that it is a very simple one:

The main part is in the server.py. When it gets invoked, it calls the flash function. It uses os.system to call the libcoap-client and time.sleep for delay parts needed in the flash action. The configuration is parsed using configparser and the server is a simple http.server.

In the end I registered the ngrok endpoint in my Azure Alert Rule Action Group:

Then I triggered my test logic app that failed reliably 🙂

After 1-2 minutes my smart light started flash:

Success 🎯🎯🎯🎯

Words of caution and Tips

Security

http.server does not provide the right level of security, it’s most for prototyping. For this tiny hobby project I have, it’s exactly what I need. Don’t use it as it is for production.

Treat the security code your preshared key appropriately, you don’t want to be hacked.

Flashing lights reacting to alerts is cool, but think about the work-life balance. Don’t have it in your bedroom 😎.

Inspect ngrok from other computer

By default the ngrok web inspect interface is only available from localhost (127.0.0.1), make it available across your network by configuring ngrok:

# ip address of your raspberry pi
echo "web_addr: 192.168.0.193:4040" >> ~/.ngrok2/ngrok.yml

Reserve your local ip addresses

The router can assign new ip addresses to your devices. Reserve the ip addresses of your raspberry pi and your IKEA Trådfri Gateway. It will make your life easier.

Start ngrok closer to you and in the background

EU is closer to me, but also running the background is nice when you only have one terminal:

# -region eu
# >/dev/null & for running in the background
~/ngrok http 192.168.0.193:8000 -region eu > /dev/null &

Replay ngrok calls

This is a game changer: rather than wait for an alert to be triggered, you can just Replay it over and over again while you mickle-muckle your python code locally.

Keep running your server after logout

You just need to to have “nohup” when you start your server, ngrok has already what’s needed: nohup python3 server.py. With that the server will run even when you log out or, your ssh connection disappears.

Next steps

I’d like to end this post also by saying: The world is your lobster. Try out the flashing lights on Azure Alerts, or why not to replace Azure Alerts with Exoprise Alarms, or some triggers in Power Automate, perhaps, when a new site has popped up 🙂 Or maybe you want to elaborate the flashing behaviour, why not to use Morse code to send a message? Or maybe color-code the different types of alarms/alerts. Once again, the world is your lobster 🦞(or oyster 🦪, well whatever) .

Setting up Raspberry Pi2 for a Dashboard Monitor

I have set up Raspberry Pi as a Dashboard Monitor a couple of times. Here I want to summarize my steps. In fact, it is nothing special, a raspberry pi that is used as a browser showing a web based dashboard in full screen, but there are some important configuration steps needed to make it as good as possible.

Install Raspbian

Raspbian is the best operating system for Raspberry Pi. Just stick with that.

Expand file storage

When you boot up Raspberry Pi, the first thing you should do is to expand the file storage, otherwise it is hard to install anything. To do so, run raspi-config from command line and restart your raspberry pi after that.

dashboard-rasp-002

Rename your raspberry

You are advised to change the password. In my case I usually just want to keep the default password: “raspberry”. What I want is to change the hostname from raspberrypi to some unique hostname (in my example it will be “kallerasp”), so that I can access it from my network without running risk for name conflicts. To rename your raspberry, update the /etc/hostname file:

sudo vim /etc/hostname

After that restart your computer.

Install iceweasel

Iceweasel is a Firefox fork, which works just fine on the raspberry pi. Update your raspberry pi and install it:

sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get install -y iceweasel

Make sure the screen is not getting blank

To use your raspberry pi as a dashboard monitor we need to prevent the screen from getting blank (dark).

cd /etc/lightdm
sudo cp lightdm.conf lightdm.conf.bak
sudo vim lightdm.conf

Update it so you have the following:

[SetDefaults]
xserver-command=X -s 0 -dpms

dashboard-rasp-001

Start dashboard page on startup

To automatically start iceweasel on startup, we need to configure autostart. To do so, run this from terminal:

cd ~/.config
mkdir autostart
cd autostart
vim .desktop

In the .desktop file write following:

[Desktop Entry]
Type=Application
Exec=iceweasel

Previously I had chromium-browser –kiosk http://someurl, but Chromiums is no longer available, and iceweasel does not have –kiosk parameter. On the other hand, you have to activate Full Screen the first time, then after OS restart iceweasel automatically will activate Full Screen and your dashboard page from the previous session.

S01E01 IoT: Posting Temperature from Raspberry Pi to Azure

Recently I have looked more at IoT, Raspberry Pi in my spare time. In my blog post I want to share my experience in a series of posts. This post is about measuring temperature, humidity and pressure with Raspberry Pi 2 Model B and Sense Hat and posting this data to Azure Table Storage.

I followed this tutorial for connecting to azure with python and these instructions for reading data from Sense Hat.

The python script is on github. Along the way I learned that only python 2.x can be used with azure and table names cannot contain underscore (I got Bad Request error when I tried to create a table with the name “climate_data”). But overall, the process was straightforward. The temperature is not correct, maybe because the sensor is inbetween Raspberry Pi and Sense Hat where it gets warm. But it is just a Proof-of-Concept.

I have used Visual Studio 2015 to see the data in Azure Table Storage. For that I needed to install Azure SDK 2.7. There are many other “explorers” for Azure Storage.

sense-001

Other resources

Accessing Azure from Linux and Mac

Improvement #1 Corrected Temperature

I found a formula for calculating more correct temperature on the raspberry pi forum.

Ta = 0.0071*Tm*Tm+0.86*Tm-10.0
Tm = measured with the temp+humidity sensor
Ta = ambient temperature

I also added a notifcation when data is sent by showing an “S” on the Sense Hat.

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