BlockyGrapher v0.91b

Physical display query grapher for Blocky DNS Server (v0.25).

I2C SSD1306 Displays with resolution 128x64 and 128x32 are supported. Note that this software in beta, and akward bugs may occur.

Preparation

Prometheus Metrics endpoint

Open your Blocky DNS Server configuration. Include HTTP server port and enable Prometheus metrics endpoint.

ports:
  dns: 53
  http: 4500

prometheus:
  enable: true
  path: /metrics

Restart server. Open your HTTP port in browser and head into metrics. You shoud see something like this:

You should not open HTTP port to the public (Unless you know what you are doing). Open your config again and edit the ports:

ports:
  dns: 53
  http: 127.0.0.1:4500

Restart server again.

Display Installation

Both supported SSD1306 displays has 4 I2C pins that we need to connect - VCC, GND, SCL/SCK, SDA.

In this example we will look at Orange PI Zero 3.

We need I2C pins here. We also need 5V (Which is VCC) pin and GND. Connect these to the display.

Enabling I2C support in SoC Board settings

On most SoC Boards you need to enable I2C devices support. In this example, we have Orange PI4 LTS with Armbian OS. We need to open armbian configuration utility sudo armbian-config and proceed to System > Hardware. Note that Orange PI4 LTS has RK3399 SoC. We need to select RK3399 I2C entries. Apply the changes and reboot.

In some cases GUI Hardware configuration tool may not be available (Like Orange PI Zero 3 with DietPI OS). In that case you need to edit startup environment file in /boot directory.

~$ nano /boot/dietpiEnv.txt

rootdev=UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
rootfstype=ext4
consoleargs=console=ttyS0,115200 console=tty1
usbstoragequirks=
extraargs=net.ifnames=0
docker_optimizations=off
overlay_path=allwinner
overlay_prefix=sun50i-h616
# We need to insert hardware I2C name in overlays. In case of Orange PI Zero 3 this is i2c3-ph.
# You can find overlays in /boot/dtb/allwinner/overlay/ or similar folder.
overlays=i2c3-ph
user_overlays=

Save and reboot.

Install python packages

Debian-based:

# install system packages
apt update
apt install i2c-tools python3-dev python3-pip python3-numpy libfreetype6-dev libjpeg-dev build-essential
# Give user permission to use i2c interface (Replace user with your username). Remember that you need re-login to user after this (You can reboot too if it didn't work for some reason).
usermod -a -G i2c user
# install python packages
pip install -r requirements.txt --break-system-packages

Finding right port/address and starting the program

In most cases pysical I2C port can differ from system I2C port binding! It's better to double-check the ports before proceeding.

i2cdetect -l can help to find port you need to use.

~$ sudo i2cdetect -l
i2c-0   i2c             mv64xxx_i2c adapter                     I2C adapter
i2c-1   i2c             DesignWare HDMI                         I2C adapter
i2c-2   i2c             mv64xxx_i2c adapter                     I2C adapter

In this example we can see that ether port 0 or port 2 is needed. Let's pick port 2.
SSD1306 128x64 and 128x32 displays usually have 0x3C/0x30 address.

~$ sudo i2cdetect -y 2
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- 3c -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

We found our display! Now we can start the grapher.

python3 BlockyGrapher.py --i2c-port 2 --i2c-address 0x3C

Note that during first successful startup, you will need to edit newly created config.ini configuration file.

[F] [16:54:12] config.ini does not exist. Please edit newly created file and start the program.

You can see all available startup options using python3 BlockyGrapher.py -h.

Cofiguration

Unedited config.ini will look like this:

[source]
url = http://127.0.0.1:4500/metrics
[appearance]
points = 14
pointsDistance = 10
dots = True
[lightsoff]
enabled = False
start = 23
stop = 06

[source]

url - Contains Prometeus endpoint URL.

[appearence]

points - Amount of points on the graph. Each point pepresents each hour passed. Note that points can can render out of display bounds.

pointsDistance - Distance between the points.

dots - Renders small dots on each hour. Improves graph readability.

[lightsoff]

enabled - Enables Lights OFF mode. During set up period in start and stop values, turns display off completely. May be useful during the nighttime, where you are sleeping and not paying attention at all (OLED displays are VERY bright during night as well).

start - Hour, when Lights OFF mode starts.

stop - Hour, when Lights OFF mode ends.

Install as service (Autorun)

After succssesful install, you probably want to install it as service.

Edit BlockyGrapher.service. The only lines you really want to change are User, Group, WorkingDirectory, ExecStart. Also uncomment and change After with service name if you have one.

Copy file.

sudo cp BlockyGrapher.service /etc/systemd/system/

Start service.

sudo systemctl start BlockyGrapher

Credits

Terminus Font - Font used by numbers in graph.

Font Awesome V4 - Icons

luma.oled - SSD1306 Display Driver