Skip to content

Latest commit

 

History

History
635 lines (437 loc) · 22.5 KB

install-signalpi.md

File metadata and controls

635 lines (437 loc) · 22.5 KB
Raw

SignalPi — The poor man’s signal tower

signalpi
SignalPi on a Raspberry Pi 3B, very early development stage :-)

We recommend installing the SignalPi module on the main Pi. You can also have a second (third …) one installed on a separate Pi Zero W.

Table of Contents

Installing on the StudioDisplay Pi

Requirements

Installation

Shutdown your Pi, disconnect the power and connect the blinkt! module. Be sure that all pins are aligned and the rounded edges of the blinkt! correspond with the reounded edges of your Pi!

Connect your Pi again and ssh into it.

ssh pi@studiodisplay1

Install Pimoroni’s blinkt! Python library. The easiest way is to use their bash script:

curl https://get.pimoroni.com/blinkt | bash

Follow the instructions and install support for both Python 2 and Python 3.

After installation, you might have to reboot your Pi:

sudo reboot

Use ssh to connect again after reboot, and verify that your blinkt! is working by trying one or more of their examples:

cd ~/Pimoroni/blinkt/examples
python rainbow.py

You should see a nice scrolling rainbow on your blinkt!. End the demo by pressing Ctrl+C.

Now let’s verify that the SignalPi software is running correctly. Assuming you haven’t changed anything in the example configuration, the following should work:

Open two termnals. In terminal 1, start the MQTT SignalPi software:

cd ~/studiodisplay/python/
./mqtt-signalpi.py

It should show that a connection has been establisehd. Also, a 3-second lamp test is performed, i.e., seven of the eight LEDs should light up for 3 seconds, then go off again.

Now let’s test some studio tower lights that might happen in real life (i.e., when broadcasting). In terminal 2, try the following:

mosquitto_pub -h studiodisplay1 -t studio/1/status/green -m on

The green Studio Ready lamp should light up.

Possible values for the lamp topics (-t) are: studio/1/status/, followed by green, yellow, red, blue and switch, respectively.

Possible values for the message (-m) are: off, on, flash and blink. (Not all lamps with work with all messages, for instance, you cannot blink or flash the 230V switch.)

You can also set the LED brighness in percent, in 1% steps. The following command would set the brightness to 5%:

mosquitto_pub -h studiodisplay1 -t signalpi/1/set/brightness -m 5

Depending on how you mount your Pi, it might be necessary to reverse the LED sequence:

mosquitto_pub -h studiodisplay1 -t signalpi/1/set/reversed -m true

(You can undo this by sending the message false.)

We even included a complete signalling test program:

cd ~/studiodisplay/python/
./signaltest.py

In terminal 1, you should see what signals were received.

Now end the test by pressing Ctrl+C in terminal 1 and closing it. Keep terminal 2 open.

Of course you want to automatically start this module whenever your StudioDisplay Pi gets booted up.

So lets add an appropriate entry in crontab for this:

crontab -e

Now add (or edit) an entry like this:

@reboot sleep 10s && /home/pi/studiodisplay/python/mqtt-signalpi.py

(We add a 10-second sleep before the actual command, so the network has time to come up. Your mileage may vary.)

Assuming you use nano to edit your crontab, now press Ctrl+O, Enter and Ctrl+X to save and exit.

You can verify that everything works correctly by doing a reboot:

sudo reboot

When booting, the lamp test should be performed. SignalPi is now ready to show the signalling going on in your studio.

As per default, it will show the following signals from the other modules (from top to bottom, for easier visualization):

LED Color Meaning
7 various UV Index (off, green, yellow, orange, red, fuchsia)
6 fuchsia State of the 230V switch on the SignalBox
5 red 230V ON AIR lamp outside the studio
4 - (unused, always off)
3 blue Call state (request line)
2 red On Air (microphone(s) open)
1 yellow Streaming
0 green Studio ready

Configuration file

You can set/modify all relevant options in the [signalpi] section of your config file.

As per default, it looks like this:

[signalpi]
; Requires a Pi with a Pimoroni "blinkt!" module
client_id = signalpi1
; connected, status/, get/, set/, command/ are internally appended to client_topic
; format: device/id/ (id CAN be something else than a number)
client_topic = signalpi/1/
; We subscribe to the studio status topic for displaying its status
subscribe_topic = studio/1/status/
; If you want to show UVI values, set this, otherwise leave blank
; Should return offical UV Index values (0 .. n)
uv_topic = weather/1/status/uv
; Initial blinkt! LED brightness (0 .. 100%)
; The LEDs are REALLY bright, so maybe 10 is enough
brightness = 10
; Due to different mounting, LEDs might have to be in reverse order
; set this to True or False
reversed = True

After making changes, you must restart mqtt-signalpi.py (or simply reboot your Pi).

Installing on a separate Pi Zero W

signalpi-zerow
SignalPi on a Raspberry Pi Zero W, next to its »big brother« (a WERMA signal tower); parts of the SignalBox hardware in the foreground. The SignalPi shows »Studio Ready« (green) and an UV index of 6 outside (orange).

We will assume that you already installed a blinkt! and SignalPI on your main system, the StudioDisplay called studiodisplay1. Thus, the number 1 for the first SignalPi is already taken and we will call our new one signalpi2.

Requirements

  • A Raspberry Pi Zero W/Zero WH, 4/8/16GB SD card with Raspian Stretch Lite installed and working WLAN connection.

  • Pimoroni’s blinkt! module (a strip of 8 RGB LEDs that can directly be attached to the Pi’s 40-pin GPIO header)

  • Pimoroni’s blinkt! Python library installed

  • The following files from our software library:

    • config/signalpi2.cfg (sections [mqtt] and [signalpi])
    • python/signalpi.py
    • python/mqtt-signalpi.py

Preparing the Pi Zero W

Download the current Raspbian Stretch Lite from raspberry.org and unzip the zip file to get the image.

cd ~/Downloads/
wget https://downloads.raspberrypi.org/raspbian_lite_latest

The downloaded file will be called something like 2018-04-18-raspbian-stretch-lite.zip.

unzip 2018-04-18-raspbian-stretch-lite.zip

This should leave us with a approx. 1.9GB file called something like 2018-04-18-raspbian-stretch-lite.img.

I suggest you now follow Rasperry Foundation’s instructions for installing operating system images and their Configuration Guidelines to get your base system up and running.

Personally, I work on Linux and typically use an abbreviated method like the following. Be careful, if you’re not sure what you’re doing you might destroy all data on your hard drive!

  • Insert the empty SD card into my system, using an adapter card.

  • Then use lsblk to find the name of my card. This is usually something like /dev/sdX or /dev/mmcblk0, where X is a lower-case letter indicating the device (i.e., /dev/sdb).

  • Unmount all partitions that the system might have mounted on the card: umount /dev/sdX1 (replace sdX1 with your SD card’s device name, and change the number for any other partitions)

  • Write the image to the card: dd bs=4M if=2018-04-18-raspbian-stretch-lite.img of=/dev/sdX conv=fsync (replace sdX with your SD card’s device name).

  • Remove and re-insert the card.

  • Your system should now auto-mount two partitions on it, called rootfs and boot.

  • Create an empty ssh file so the Pi will enable SSH when booting:

    cd /media/$USER/boot/
touch ssh

  • Create the file wpa_supplicant.conf in the card’s boot partition so the Pi Zero W will be able to connect to the WLAN:

    nano wpa_supplicant.conf

  • Fill in the following, and correct for your country, SSID and WLAN password:

    ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=DE
network={
    ssid="YOUR_SSID"
    psk="YOUR_PASSWORD"
    scan_ssid=1
}

    Save the file and exit nano.

  • You can now sync the changes to the filesystem, unmount the partitions and remove the SD card from your PC:

    sync
umount /media/$USER/boot
umount /media/$USER/rootfs

  • Mount the blinkt! on your Pi Zero W, insert the new SD card, connect power and boot it up.

Use ssh (or PuTTY) to connect to your Pi

If you are using a fresh installation of Raspbian Lite, connect to your Pi as follows:

ssh pi@raspberrypi

(The default password is raspberry, you should change it using raspi-config!)

If you have already changed the hostname as suggested, use:

ssh pi@signalpi2

and enter your password when requested to do so.

Note: Depending on your local network setup, you might have to use a FQDN (Fully Qualified Domain Name) instead of just the hostname. Simple cases might look like signalpi2.local, more complicated setups in large companies might even look like signalpi2.hamburg.studios.bigbroadcastingcompany.com. Ask your IT admin and just substitute the correct name in the examples.

On Linux, once a system has been set up, you can find its hostname in a terminal like this:

hostname

Note: The name returned by the hostname command is also the name to be used for your StudioDisplay configuration file. So if your hostname was really signalpi2.hamburg.studios.bigbroadcastingcompany.com, you would have to call it signalpi2.hamburg.studios.bigbroadcastingcompany.com.cfg instead of just signalpi2.cfg.

Change the Pi’s hostname and passwords

On a fresh installation of Raspbian Lite, your Pi will be found in your local network under the hostname raspberrypi (you might need to use raspberrypi.local for ssh and browser access).

The default username is pi and the default password is raspberry. This is of course a security risk since everybody knows these.

We want to give our Pi a speaking name like signalpi2 in the network (you might have more than one and call the next one signalpi3) and also change the default passwords to something more secure.

Change the hostname

Log into your Pi using SSH. Since this is a fresh installation, the system name is still raspberrypi and the user’s password is raspberry.

ssh pi@raspberrypi

When connected, use raspi-config to change the hostname and other important settings (country, language, timezone, …):

sudo raspi-config

Note: raspi-config doesn’t support a mouse. You must use the keyboard. Jump between fields using Tab (forward) and Shift+Tab (backward). Enter selects/executes the marked option.

  • Select 2 Network Options and press Enter.
  • Select N1 Hostname and press Enter.
  • Read the notice about allowed hostnames and press Enter.
  • In the input field, change the hostname to signalpi2 and press Enter.
  • From the main screen, use the Tab key to select Finish and press Enter.
  • When asked Would you like to reboot now?, select Yes and press Enter.

Your Pi will now reboot. Wait a while and then reconnect your SSH session, using the new hostname signalpi2:

ssh pi@signalpi2

Change the user password

Now we go and change the password for the user pi:

passwd

You will have to legitimate using the current password (which is still raspberry) and then enter your new password twice.

Note: On a console, your password input is never echoed, not even as dots or asterisks, so it is normal that you don’t see anything while you type your password.

Hint: For security reasons, passwords have to have a minimum length and complexity. If your password is too short or too simple, passwd will let you know.

If all went well, you’ll get a message that your password has been changed. Remember it well or write it down in a secure place.

Let’s test if all went okay by logging out and back in again:

logout
ssh pi@signalpi2

Hint: You can also log out from a terminal or SSH session by pressing Ctrl+D.

Use your new password this time to log in.

Copying the software

Copy or git clone the software to your home folder on the Pi, into a folder named studiodisplay.

Example:

cd
git clone https://github.com/Moonbase59/studiodisplay.git
cd studiodisplay

Make the Python modules in ~/studiodisplay/python executable:

cd ~/studiodisplay/python/
chmod +x mqtt-*.py
chmod +x signaltest.py

You must have a configuration file set up in ~/studiodisplay/config/ that corresponds with your chosen hostname, i.e. signalpi2.

For starters, just copy and edit the example configuration file:

cd ~/studiodisplay/config/
cp example.cfg signalpi2.cfg

You can edit this file with nano, a very minimalistic commandline editor:

nano signalpi2.cfg

Changes are written with Ctrl+O and then pressing Enter. Exit nano with Ctrl+X.

Update your Pi’s software

sudo apt-get update
sudo apt-get dist-upgrade
sudo rpi-update

Reboot as neccessary.

Install Python pip

We might need to install pip and pip3 before we can use it.

sudo apt-get install python-pip python3-pip

Install the Python MQTT client software

We use Eclipse’s Paho client.

sudo pip install paho-mqtt
sudo pip3 install paho-mqtt

Configure the MQTT broker to use

Let’s edit the [mqtt] section of your config file, ~/studiodisplay/config/signalpi2.cfg, to let the software modules know which broker to talk to. If you followed my instructions on how to install everything on the StudioDisplay Pi, the broker should run on studiodisplay1.

nano ~/studiodisplay/config/signalpi2.cfg

The [mqtt] section should look like this:

[mqtt]
; ALL modules read from this section to find their broker connection data
; For simplicity and energy-saving, we run the MQTT broker
; on the first StudioDisplay (a Raspberry Pi 3B or 3B+).
host = studiodisplay1
port = 1883
websockets_port = 9001
; Base topic to distinguish different users, etc. Can be left empty.
base_topic =

Configure the SignalPi

While we are still editing the configuration file ~/studiodisplay/config/signalpi2.cfg, let’s set the SignalPi options in the [signalpi] section for this system. Remember this one shall be number 2 because we already used number 1 for the main Pi.

[signalpi]
; Requires a Pi with a Pimoroni "blinkt!" module
client_id = signalpi2
; connected, status/, get/, set/, command/ are internally appended to client_topic
; format: device/id/ (id CAN be something else than a number)
client_topic = signalpi/2/
; We subscribe to the studio status topic for displaying its status
subscribe_topic = studio/1/status/
; If you want to show UVI values, set this, otherwise leave blank
; Should return offical UV Index values (0 .. n)
uv_topic = weather/1/status/uv
; Initial blinkt! LED brightness (0 .. 100%)
; The LEDs are REALLY bright, so maybe 10 is enough
brightness = 10
; Due to different mounting, LEDs might have to be in reverse order
; set this to True or False
reversed = True

We renumbered the client_id (because it must be unique) and the client_topic (because each data provider or device has its own topic on the broker). We didn’t change subscribe_topic because we only have one studio, and we didn’t change uv_topic because we only have one weather provider.

Now save the file (Ctrl+O, Enter) and exit the editor (Ctrl+X).

Install the blinkt! library

If you have not already done so, shutdown your Pi, disconnect the power and connect the blinkt! module. Be sure that all pins are aligned and the rounded edges of the blinkt! correspond with the reounded edges of your Pi!

Connect your Pi again and ssh into it.

ssh pi@signalpi2

Install Pimoroni’s blinkt! Python library. The easiest way is to use their bash script:

curl https://get.pimoroni.com/blinkt | bash

Follow the instructions and install support for both Python 2 and Python 3.

After installation, you might have to reboot your Pi:

sudo reboot

Use ssh to connect again after reboot, and verify that your blinkt! is working by trying one or more of their examples:

cd ~/Pimoroni/blinkt/examples
python rainbow.py

You should see a nice scrolling rainbow on your blinkt!. End the demo by pressing Ctrl+C.

Now let’s verify that the SignalPi software is running correctly. Assuming you haven’t changed anything in the example configuration, the following should work:

Open two termnals. In terminal 1, start the MQTT SignalPi software:

cd ~/studiodisplay/python/
./mqtt-signalpi.py

It should show that a connection has been establisehd. Also, a 3-second lamp test is performed, i.e., seven of the eight LEDs should light up for 3 seconds, then go off again.

Now let’s test some studio tower lights that might happen in real life (i.e., when broadcasting). In terminal 2, try the following:

mosquitto_pub -h studiodisplay1 -t studio/1/status/green -m on

The green Studio Ready lamp should light up.

Possible values for the lamp topics (-t) are: studio/1/status/, followed by green, yellow, red, blue and switch, respectively.

Possible values for the message (-m) are: off, on, flash and blink. (Not all lamps with work with all messages, for instance, you cannot blink or flash the 230V switch.)

You can also set the LED brighness in percent, in 1% steps. The following command would set the brightness to 5%:

mosquitto_pub -h studiodisplay1 -t signalpi/2/set/brightness -m 5

Depending on how you mount your Pi, it might be necessary to reverse the LED sequence:

mosquitto_pub -h studiodisplay1 -t signalpi/2/set/reversed -m true

(You can undo this by sending the message false.)

We even included a complete signalling test program:

cd ~/studiodisplay/python/
./signaltest.py

In terminal 1, you should see what signals were received.

Now end the test by pressing Ctrl+C in terminal 1 and closing it. Keep terminal 2 open.

Of course you want to automatically start this module whenever your SignalPi gets booted up.

So lets add an appropriate entry in crontab for this:

crontab -e

Now add (or edit) an entry like this:

@reboot sleep 10s && /home/pi/studiodisplay/python/mqtt-signalpi.py &

(We add a 10-second sleep before the actual command, so the network has time to come up. Your mileage may vary.)

Assuming you use nano to edit your crontab, now press Ctrl+O, Enter and Ctrl+X to save and exit.

You can verify that everything works correctly by doing a reboot:

sudo reboot

When booting, the lamp test should be performed. SignalPi is now ready to show the signalling going on in your studio.

As per default, it will show the following signals from the other modules (from top to bottom, for easier visualization):

LED Color Meaning
7 various UV Index (off, green, yellow, orange, red, fuchsia)
6 fuchsia State of the 230V switch on the SignalBox
5 red 230V ON AIR lamp outside the studio
4 - (unused, always off)
3 blue Call state (request line)
2 red On Air (microphone(s) open)
1 yellow Streaming
0 green Studio ready

Configuration file

You can set/modify all relevant options in the [signalpi] section of your config file.

As per our changes, it now looks like this:

[signalpi]
; Requires a Pi with a Pimoroni "blinkt!" module
client_id = signalpi2
; connected, status/, get/, set/, command/ are internally appended to client_topic
; format: device/id/ (id CAN be something else than a number)
client_topic = signalpi/2/
; We subscribe to the studio status topic for displaying its status
subscribe_topic = studio/1/status/
; If you want to show UVI values, set this, otherwise leave blank
; Should return offical UV Index values (0 .. n)
uv_topic = weather/1/status/uv
; Initial blinkt! LED brightness (0 .. 100%)
; The LEDs are REALLY bright, so maybe 10 is enough
brightness = 10
; Due to different mounting, LEDs might have to be in reverse order
; set this to True or False
reversed = True

After making changes, you must restart mqtt-signalpi.py (or simply reboot your Pi).