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Recent Posts

Analyzing a VeSync power socket

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I recently acquired a set of “smart” power sockets, mostly to measure power consumption of different devices and appliances in my home. Those sockets labeled “GreenSun” require the use of the VeSync app. I do have a history with wireless power sockets so I wanted to take a slightly deeper look into those devices and see if I can get them to run locally without any cloud requirements. I’m sharing this in case others want to continue looking into these devices based on these insights and to shed some light on the procedure. Read More...

Embroidery-embedded sewable electronic circuits

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In this post I’m sharing my prototyping for integrating a LED + battery into an embroidery design, and wanted to get a little more elaborate than just using an adafruit sewable LED with an external battery. Ideally I wanted something that can be integrated in a T-shirt or at least a sweater. After reading about this topic during the last year, what caught my eye was a seemingly forgotten idea of building LED sequins using small silver beads from Buechley and Eisenberg in 2007. Read More...

Fritz-Box VPN with strongswan and DS-Lite

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Setting up a working ipsec configuration for the fritz-box seems to be rather painful. I couldn’t make the default wizard variants work since they seem to use aggressive mode with psk and I was getting errors such as: found 1 matching config, but none allows pre-shared key authentication using Aggressive Mode It took me a while, so here are some working results from me. Hopefully your journey becomes easier then :) Read More...

HC-12 Hacking

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I have a strange obsession with the STM8 microcontroller. Arguably because it’s so cheap (you could get in in bulk from <0,40€ per piece or for 0,60€ on a dev-board), but powerful and versatile at the same time, due to: lots of GPIOs UART/SPI/I2C/ADC low power proper interrupts works both at 3.3V and 5V When investigating radio communication for some hobby projects a few years I stumbled upon the HC-12 module which easily adds wireless serial communication to your project. Read More...

Low-cost attacks on STM8 readout protection

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As part of my HC-12 hacking project I needed to acquire the firmware of an STM8 microcontroller that had readout protection enabled. I was long-time intrigued by fault-injection attacks, most recently triggered by this 35C3 Talk on PS2 Vita Hacking which used voltage glitching to overcome protection measures. From the STM8 reference manual: 4.5.1: Readout protection Readout protection is selected by programming the ROP option byte to 0xAA. When readout protection is enabled, reading or modifying the Flash program memory and DATA area [using the SWIM debug interface] is forbidden. Read More...


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