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

Solar PV, Batteries and … Maths

Some, it all seems pretty simple, right? It’s just import, export, consumption. This post clarifies the sign (+ or -) conventions I use which seem to make things easiest. Each of the three images has a ‘control volume’ where we measure power […]

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 […]

Insulating a Queenslander

Stud Walls Often you can’t access the wall without removing weatherboard or plaster. However, the stud bays in my house are open – no noggings, few wires. Therefore I’ll try to pump in insulation via (1) top (2) bottom or (3) a […]

Big Pete and The Champ

Big Pete Pre made wort: 1/2 whiskey wort, 1/2 smoked porter Dry malt: dark, 1kg Yeast: Belgium yeast 2 week ferment Dextrose: 70g Tastes ok on bottling. The Champ Pre made wort: 1/2 whiskey wort, 1/2 smoked porter Belgium yeast Primary ferment […]

Zinken Compact 21 : Repairs

I bought this unit in Brisbane, Australia. This records details in case they are useful to others. Bearings Bearings were mostly stuffed after 30 years. They are metric and available from standard suppliers. Steel sides (ZZ). Spindle Molder Belt Idler: 6000 (x2) […]

PiZeroW AP + Wifi Client

So I wanted to be able to set the Wifi details of a Pi without connecting a monitor and keyboard. Easy, right? No. RaspAP almost does it out-of-the-box, but I couldn’t quite crack it. It’s the best solution once it’s working. Insetad […]

Time Travel, unittest.mock, freezegun and monkeypatch

To test time-dependant programs, such as timelapse camera, we can fudge the system time (sleep,. now()) in Python. Some options are: This is easy to use, but doesn’t manage sleep(). Use monkeypatch to override sleep(). Another is unittest.mock (good intro) which […]

Ubuntu 18 on Dell Windows 10

Notes on how to install and tune a HyperV VM running Ubuntu linux, for development. Did this March 2020. Did it on an older 6430u Dell and a brand new Dell laptop. VM HyperV Need Windows Pro and HyperV install. Use “Quick […]