When I was looking for a decent hardware for a paragliding instrument I came across the E-Book readers from Rakuten called Kobo.These machines provide a decent e-ink display together with a pretty capable hardware running Linux. The main reason they are so popular among paragliding pilots is the c...

It's been some time since I bought the Cubot KingKong Mini 2. It's been working pretty well all these years, but the battery life is not so good any longer, the phone is scratched from all sides, modern android apps are quite often very slow (e.g. windy is almost non-usable,...). So it's time to...

During my hunt for literature about aircraft design I found several interesting old books scanned to PDF online, these raw scans are hard to read, especially when both pages are scanned on a single PDF page. I've spent some time looking for a best way to clean up the scans and transform them to a go...

The LTSpice is a great and free simulation tool for analog circuits. During design phase of my buck converter I needed to simulate the digital part, notably a fixed pulse length generator triggered by signal edge. The LTSpice is great for analog, but when it comes to digital domain, very few parts...

The Catch is an online competition/challenge in the computer security organized annually by the Cesnet. I didn't really have time to look into it, but a friend of mine started solving some of the challenges and that finally kicked me in my lazy butt so I decided I can spare few lunch pauses... I...

I quite like the Gitlab way of working with runners, the runner is a small docker container that is managing jobs in other containers, easy to install and maintain. It would be nice if Jenkins could do it too. Well, it actually can, but if need to run jobs in Windows containers, the journey to wor...

When it comes to Enterprise WiFi, the simple - plug-in, set your password and enjoy - approach doesn't work as expected, especially if you have multiple APs around and need to implement fast transitioning between them. Also how to authorize the WPA2-EAP clients in your network? You need some server...

My old Xiaomi Redmi stopped showing red channel, so it was time to enter the hell of Android devices marked and find the least crappy device out there. I've selected the cheap and tiny Cubot KingKong Mini 2 (4 inch phone in 2021? finally someone started making small Android phones!).

The name of t...

When playing with the RFM95 LoRa chip, I was surprised how complicated it is to reduce the power consumption to the values advertised in the datasheet. I happily designed the Picoballon probe for 2021 competition without any means of switching RFM95 the to save some PCB space and weight, the adv...

There's a sentence in the proxmox cluster setup guide: Changing the hostname and IP is not possible after cluster creation. We are running a 4 node cluster that was placed in a legacy network. As the company grew from few people to something bigger, I wanted to split the network into VLANs for i...