My repositories at GitHub.
Find some 3D printable parts, an Arduino RF meter for a ZX47-55,
an Arduino P13 satellite prediction library, ...

A single chip web pc based on a BECK SC12.

An AD9851 based shortwave DDS-VFO with a DRM receiver frontend.
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Based upon my DDS-VFO and a simple antenna analyzer by IW3HEV I build this microcontrolled VNA.
The S-parameters S11 and S21 can be measured. The measurement results can be transfered via RS232
or USB (from which the VNA can be powered).

Smaller, better, cooler: edy555's NanoVNA and NanoRFE's NanoVNA v2

Based on the original programmer by DL2TM, I developed a SMD version with a few enhancements.
The programmer works for the AT89C2051 and AT89C4051 micros.

A homemade basic 128MBit flashcart (FLASH only!) for the Gameboy Advance.
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Some stuff around the SkyTraq Venus 6 EVK/SDK
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Some stuff around the SDCC compiler