OpenVPN for IoT

Using a AWS Linux server, and Raspberry Pi, Ubuntu or Robustel router clients Situation Lots of linux devices (and embedded devices) behind firewalls without public IP address Publicly accessible computer (AWS) Goals Connect from the server (or office PC) to these devices […]

linux commands

Test OpenVPN server on it’s standard UDP port telnet is so 2020 so use nc which does UDP too -v verbose -z test daemon -u UDP

Debugging Pi from VSCode

There’s a few tutorials and references for debugging a python program on a remote (e.g. pi) computer. I had to fiddle a fair bit to get VSCode, ssh and debugpy to work. Here is how. Traps and Notes ptvsd is depreceated run […]

Backup and Restore SD Cards using linux

Once a Pi is setup, it’s useful to clone the SD card and save the state. Here’s how. But wait! Is it exactly the same on a different machine? No! Change the cloned Pi a bit: Hostname (raspi-config and reboot) AP and […]

Battery PiZero W, PiJuice Zero and a Camera

Goal Make a really simple timelapse camera. Runs on a Pi and uploads photos when WiFi available Always taking photos and saving. Always trying to upload photos. Wifi setup to act as host or client Option: Battery Bank Not that efficient but […]

Raspberry Pi Setup (Linux)

Setup SD Card on another linux machine to install headless I use Desktop Raspberry Pi OS distro. This is tested on a Pi Zero and a Pi 4 in Feb 2020. Insert a new SD card (e.g. /dev/sdc/). The check the install […]

SSH Port Forwarding

There’s heaps on this on the internet and a good book. Here is my usage, which is useful for IoT connections. Remote Server Access I want to connect remotely to a web server on machine.com. But it’s behind a firewall which refuses […]

Hacking an IotaWatt ESP8266

I need to flash the IotaWatt firmware (and write new files to the SD card) for two reasons: firstly I have a bricked IotaWatt, and secondly I want to try to modify the firmware to sample at 1 seconds intervals. Resources https://community.iotawatt.com […]

Grafana and InfluxDB on a Pi

Instructions as of late 2019! I used a Pi Zero W. This works but was pretty slow and awful for a my application. I then tried with a RPi 4B 2Gb and a RPi 3B. Preliminary From linux docs or see my […]

Access Grafana v6 without a login screen

Unlike Grafana 5, we can’t use the ‘old’ method of a proxy login to get a cookie for semi-permanent login. This post investigates options to achieve the goal of: Provide a user a “secret” URL which allows them to login to grafana […]