Lasair data monitoring RGB matrix

The simplest way to run the event display uses a compute monitor, and does not require installing hardware. Simply install the OpenCV package, and in the settings.py file put RGBmatrix = False. Then python3 master.py on the command line and the display will come up.

The instructions below are about the wall-mounted display, with RGBmatrix = True.

This wall-mounted display shows the status of the Lasair data flow, and can be adapted for other purposes. Total cost is about $130. There is a 32x32 RGB matrix powered by a Raspberry Pi, and they can be mounted in a box-frame to make a wall-mounted display. There are two power cables, one a USB to power the RPi, the other a 5V supply for the matrix. The RPi needs to be on a wifi network, and the instructions below assume an external computer is on the same wifi.

Each alert that arrives has RA and Dec in the sky: RA is 0-360 left to right, and Dec is -25-90 bottom to top. The corresponding LED lights up, and fades gradually over about 10 minutes. Further, there is Conway's Game of Life that is triggered, so that rapid movement continues on the matrix even after the alerts stop.

You will need

• Raspberry Pi $30
• 32x32 RGB LED Matrix Panel $35
• Adafruit Hat for matrix $25
• SD/MicroSD Memory Card with adapter $10
• 5V power supply for the matrix $8
• 3D box frame $14 -- to show the matrix and keep the RPi in the back
• Micro USB powercable $5
• A computer for connecting and controlling, with SD card slot.
• A wifi network that both the RPi and the external computer can use.
• External screen, USB mouse, USB keyboard.

Assembly and Software

• Put your microSD into its adapter and connect to your external computer.
• Install a Raspberry Pi imager on your external computer.
• Run the imager, select latest RPi and install to the SD card.
• Follow the Adafruit instructions, steps 1-5.
• Connect a screen to the RPi with the Micro-HDMI, and connect the mouse and keyboard.
• Put the microSD card into the RPi and switch on power, give it username and password when prompted. YOu will need to connect it to your wifi network.
• Enable ssh for the RPi with sudo raspi-config then select Interface Options / SSH. Then use hostname -I to get the IP address so you can ssh to it.
• Now you can put the RPi and matrix into the frame and hang it on the wall. Plug in both the USB and 5V power.
• Connect to your RPi with
• Continue the Adafruit instructions with step 6. Make sure the examples work.

Kafka and Lasair software

• Build librdkafka from source like this

git clone https://github.com/edenhill/librdkafka.git
cd librdkafka
./configure
make
sudo make install

• Install confluent kafka. I used a slightly downrev version for this:

pip3 install confluent_kafka==1.8.2

• Fetch the code that uses Lasair for the matrix

git clone https://github.com/RoyWilliams/RGBMatrix

• Now see if it works

sudo python3 master.py

• You can install screen so that it runs even when the SSH is disconnected

sudo apt-get install screen