HPR4251: Dave and MrX turn over a new leaf

Hacker Public Radio

Introduction Hosts: MrX Dave Morriss We recorded this on Saturday September 14th 2024. This time we were at Swanston Farm, a place we had previously visited for lunch in March 2024. After lunch we adjourned to Dave's car (Studio N) in the car park, and recorded a chat. The details of why it is Studio N instead of Studio C is mentioned in the chat itself! Preparing this show has taken longer than usual this time - apologies! Topics discussed Studio change: Sadly, since the last recording Studio C (Dave's 10-year old Citroën C4 Picasso) self-destructed. It was a diesel car and one of the fuel injectors failed and destroyed the engine management system as it died. It wasn't worth repairing! The replacement is Studio N, a Nissan Leaf, which is an EV (electric vehicle). The price of nearly new EV cars is fairly good in the UK at this time in 2024, so it seemed like a good opportunity to get one. Learning to own and drive an EV can be challenging to some extent: "Range anxiety" and access to charging stations Regenerative braking Fast (DC) charging on the road is relatively expensive (£0.79p per kWh), but is convenient Ideally, a home (AC) charger is required. It will be slower (7 kW per hour) but will be cheaper with a night tariff (£0.085 per kWh versus £0.25 per kWh normal rate) There is potential, with solar panels and a battery, to use free electricity to charge an EV at home MrX might like to move to an EV in the future YouTube channels: Dave is subscribed to a channel called "The Post Apocalyptic Inventor (TPAI)" and recently shared one of the latest videos with MrX. The channel owner collects discarded items from scrapyards in Germany, or buys old bits of equipment, and gets them working again. Milling Machine Adventure! Bring her Home! / Gantry Build I built a CNC Plasma Cutting Table from Scrap! Databases: MrX used dBase on DOS in the past, and received some training in databases. In 2017 he obtained a large csv (comma-separated values) file from the OFCOM (Office of Communications, UK) website containing their Wireless Legacy Register, which contains licensees and frequencies with longitude and latitude values. A means of interrogating this file was sought, having found that spreadsheets were not really very good at handling files of this size (around 200,000 records). MrX used the xsv tool, which was covered in shows hpr2698 and hpr2752 by Mr. Young. It allows a CSV file to be interrogated in quite a lot of detail from the command line. However, with a file of this size it was still quite slow. In a discu