Marcus Folkesson

Embedded Linux Artist

Remotely controlled USB hub

Remotely controlled USB hub This is no fancy project, but I thought it might be useful for someone out there. There is probably better ways to do this, but this is what I came up with. My situation For those who haven't read my previous post [1], I have recently bought two (yes, TWO!) Rigol DP832 power supplies to power my lab equipment. (I really love them and will never use a non-programmable power supply without ethernet interface again.

cover

Posted by Marcus Folkesson on Saturday, January 17, 2026

GNSS spoofing using SDR

GNSS spoofing using SDR First of all, sending false GNSS signals on the air is illegal in most countries. You must have a controlled RF environment (Faraday cage or such) to perform GNSS spoofing experiments. A box covered with aluminum foil with copper tape in all joints works quite well, but be sure everything (holes for cables, joints etc) are properly shielded. The best is to not transmit to open air at all, but using coax cables only.

cover

Posted by Marcus Folkesson on Thursday, January 15, 2026

Repair of my Fluke 179 multimeter

Repair of my Fluke 179 multimeter My belowed Fluke 179 multimeter suddenly stopped working. There was no display, no beeps, nothing. I have had this multimeter for many (12+) years, and it has been a reliable companion in my projects. Fluke has a lifetime warrenty, but that only applies to the original owner, and I bought it second hand. Troubleshooting Here is what I did to troubleshoot the problem.

cover

Posted by Marcus Folkesson on Thursday, July 3, 2025

An attempt to learn blindfolded chess

An attempt to learn blindfolded chess This is one of my more unusual projects, but I still think it is worth sharing. First of all, I do not consider myself as a skilled chess player. I would not say that I'm bad, but I have a lot more to learn. My ELO at Lichess is about 1400. I have played chess since I was a kid, but I have never been serious about it.

cover

Posted by Marcus Folkesson on Friday, March 7, 2025

Repair of Sennheiser Momentum True Wireless earbuds

Repair of Sennheiser Momentum True Wireless earbuds I have a pair of Sennheiser Momentum True Wireless (MTW3) earbuds that had been lost for a while. Once I found them, they had been laying around for a while and the battery was completely drained. I tried to charge them, but they did not charge at all. They are completely dead. Here they are. What I could see, there was no obvious way to open them up.

cover

Posted by Marcus Folkesson on Friday, January 10, 2025

Control of my geothermal heat pump

Control of my geothermal heat pump The electicity price in Sweden varies a lot during the day. It's usually cheapest during the night and most expensive during the day, but not always. One day a week ago, it was not much wind in Germany and therefore we exported electricity there which resulted in very high prices here in Sweden. 1 kWh cost over 10 SEK (almost 1 USD per kWh) for a few hours, this excluding transmission fees and taxes.

cover

Posted by Marcus Folkesson on Thursday, December 19, 2024

Restoring a power hammer

Restoring a power hammer I have bought myself a power hammer - something that I have wanted for a long time. It is a Abno nr1, a swedish made 25kg spring hammer. It has been unused for many years and is in need of a little restoration. The last Abno hammers were manufactured in the sixties, so it is at least 60 years old. I've seen 60 year olds in worse condition than this, although there are parts that need improvement.

cover

Posted by Marcus Folkesson on Saturday, October 19, 2024

Forge a kitchen knife

Forge a kitchen knife Another attempt to forge a knife. The metal I use for this project is part of a feather harrow that I collected from my father farm. I cut out a ~8x4cm long piece from the springs of the feather harrow: Bosse (the dog) never leaves me, so I got him a sack to snuggle down on at the outside of the garage. I used the gas forge for the entire project.

cover

Posted by Marcus Folkesson on Thursday, August 1, 2024

Forge a knife blade from a car spring

Forge a knife blade from a car spring I helped my friend to change springs on his car, so I kept the broken spring as forging material. The carbon content of spring steel is aroundd 0.6 to 0.8% which works well for hardening - so lets forge a knife! I cut out a ~10cm long piece from the car spring. I use the induction heater to straight it out and flatten it a little.

cover

Posted by Marcus Folkesson on Sunday, July 14, 2024

Knife making

Knife Making It's been a long time since I made knives. Knife making was actually the reason I bought my gas forge a few years ago and it's still something I intend to do. I forged a few knife blades back then, but it was way too much manual grinding to be fun and I didn't have the right tools back then, and I'm still missing a belt grinder in my toolbox.

cover

Posted by Marcus Folkesson on Monday, July 1, 2024