Saturday, 20 June 2026

How to provide remotely accessible graphs on a Raspberry Pi

 So in this blog we will provide remotely accessible graphs on a Raspberry Pi. The RPi in question is in the 40' container of Shannon Tidy Towns in Drumgeely. I anticipate accomplishing this by the following steps:

1) Get a NoIp domain name installed on the Rpi (noip2)

2) Install webserver (apache2)

3) Install graphing software (dash_plotly)

4) Install database (sqlite3)

5) Gather (TTN, MQTT, WiFi) and post data to graph to the database

6) Created graph web pages


Most of the above has already been done by me on my RPi smart home host called calendula. So let's go through the stages...


I have an account (kilnageer@gmail.com) at https://my.noip.com/ and a number of free domains already registered. So let's use snntt57.zapto.org (which was last updated as 86.41.249.104 on Jun 17, 2026 09:27:10)


So using SSH over Zerotier I can talk to this remote Rpi and see what code it is running.

pi@drumgeely:~ $ df -m .
Filesystem     1M-blocks  Used Available Use% Mounted on
/dev/mmcblk0p2     14351 12017      1585  89% /
pi@drumgeely:~ $ sudo systemctl status apache2
Unit apache2.service could not be found.
pi@drumgeely:~ $ 


It has less than 2GB left on its 16GB microSD card and no Apache2 webserver running.

pi@drumgeely:~ $ sudo apt install apache2


pi@drumgeely:~ $ date
Sat 20 Jun 12:43:20 IST 2026
pi@drumgeely:~ $

pi@drumgeely:~ $ sudo systemctl status apache2.service 
● apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; preset: enab>
     Active: active (running) since Sat 2026-06-20 12:32:45 IST; 11min ago
       Docs: https://httpd.apache.org/docs/2.4/
   Main PID: 26473 (apache2)
      Tasks: 55 (limit: 1556)
        CPU: 337ms
     CGroup: /system.slice/apache2.service
             ├─26473 /usr/sbin/apache2 -k start
             ├─26475 /usr/sbin/apache2 -k start
             └─26476 /usr/sbin/apache2 -k start
Jun 20 12:32:45 drumgeely systemd[1]: Starting apache2.service - The Apache HTT>
Jun 20 12:32:45 drumgeely apachectl[26472]: AH00558: apache2: Could not reliabl>
Jun 20 12:32:45 drumgeely systemd[1]: Started apache2.service - The Apache HTTP>
pi@drumgeely:~ $ 



I then tried accessing this RPi using its Zerotier IP address and I saw the Apache2 landing page. So step 2) above achieved.


Next to install the noip client that will periodically inform the No-Ip server which IP address is current assigned to this Drumgeely RPi

https://my.noip.com/dynamic-dns/duc - no good for RPi

https://raspberrytips.com/install-no-ip-raspberry-pi/ - OK

So had to build and install for Rpi using above instructions then run to perform an IP update..


pi@drumgeely:~/noip/noip-2.1.9-1 $ sudo noip2 -c /usr/local/etc/no-ip2.conf


Can then see the update at:
https://my.noip.com/dns/records?jump_to_zone=zapto.org

snntt57     A    188.65.190.74    60    Jun 20, 2026 13:00:20

###TODO Will need to make this noip2 command into a systemctl service.


But the laptop web browser still doe not get the Apache2 landing page at:

http://snntt57.zapto.org/

So may need to map port 22 through the Tenda router. Unfortunately, after logging in to the Tenda portal, via the Android app, I could see the Tenda_D986A0 device and the drumgeely Rpi and Solas WiFi dongle but the portal app gave no port mapping options. 

###TODO So may need to log in to this router locally to do this! And assign a static LAN address to the drumgeely Rpi.

Or log into the drumgeely Rpi over VNC and then launch a browser to the router at 192.168.0.1


Set static DHCP address and DMZ but still cannot remote access Apache2 server. (Also set DDNS to noip http://snntt57.zapto.org/)

###PROBLEM still cannot remotely access via http://snntt57.zapto.org/ buut OK via Zerotier IP address

###SOLUTION webscrape graphical pages and republish to ShannonTownWetlands.ie website for public access.



So I will park this up for now and get the graphing software installed..

https://dash.plotly.com/installation

pi@drumgeely:~ $ mkdir dash_plotly

pi@drumgeely:~ $ python3 -m venv ./dash_plotly/

pi@drumgeely:~ $ source ./dash_plotly/bin/activate

(dash_plotly) pi@drumgeely:~ $ 

(dash_plotly) pi@drumgeely:~ $ pip install dash

Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple


###PROBLEM After lots of timeouts installing I then got a runtime error..


(dash_plotly) pi@drumgeely:~/dash_plotly $ python ./app.py 

Traceback (most recent call last):

  File "/home/pi/dash_plotly/./app.py", line 2, in <module>

    import plotly.express as px

  File "/home/pi/dash_plotly/lib/python3.11/site-packages/plotly/express/__init__.py", line 12, in <module>

    raise ImportError(

ImportError: Plotly Express requires numpy to be installed. You can install numpy using pip with:


$ pip install numpy


Or install Plotly Express and its dependencies directly with:


$ pip install "plotly[express]"


You can also use Plotly Graph Objects to create a large number of charts without installing

numpy. See examples here: https://plotly.com/python/graph-objects/


(dash_plotly) pi@drumgeely:~/dash_plotly $ 


Same code runs OK on calendula Rpi!


Tried editing xxxxx/_init_.py see:

https://stackoverflow.com/questions/69866554/trying-to-import-plotly-express-but-get-this-error-even-though-pandas-is-install

but didn't help


Moved on to install sqlite3

https://www.tech-reader.blog/2025/08/installing-and-verifying-sqlite-on.html


pi@drumgeely:~ $ sudo apt install sqlite3


pi@drumgeely:~ $ sqlite3 --version

3.40.1 2022-12-28 14:03:47 df5c253c0b3dd24916e4ec7cf77d3db5294cc9fd45ae7b9c5e82ad8197f3alt1

pi@drumgeely:~ $