RF Testing

We are working on reversing the Huidu HD-R712 LED Display Full Color Receiving Card - a very cost-effective (~1000 INR) and widely available FPGA board. We draw inspiration from the https://github.com/q3k/chubby75 work. FPGA Blink Project Files 1 Random brain dump $ sudo openFPGALoader --cable dirtyJtag --freq 10000 --detect Jtag frequency : requested 10000Hz -> real 10000Hz index 0: idcode 0x4014c35 manufacturer anlogic family eagle d20 model EG4D20EG176 irlength 8 $ sudo openFPGALoader --cable dirtyJtag --detect Jtag frequency : requested 6000000Hz -> real 6000000Hz index 0: idcode 0x4014c35 manufacturer anlogic family eagle d20 model EG4D20EG176 irlength 8 JTAG pinout: V ┌───────────────────┐ │ 1 3 5 7 9 │ │ 2 4 6 8 10 │ └───────────────────┘ 9 => TCK 7 => TDO 5 => TMS 3 => NC (Not Connected) 1 => TDI The pin mapping work was done using a DMM, the datasheet, and an optical magnifier. ...

Polar Modulation for Everyone We have been working on SSB generation using polar modulation. Hardware stack: RP2350-Zero MCU board + Fast Si5351 module + AP63301 buck regulator (for 5W mode). See https://github.com/kholia/PolarModulationSSB for details. Audio fidelity is acceptable at the moment and should improve further. We still need to hook up the amplitude ("envelope") restoration stage. Motivation Why should Guido, Hans, and FlexRadio folks have all the fun? ;) ...

We make heavy use of Easy-Digital-Beacons-v1 for testing RF amplifiers. This single board is a versatile WiFi VFO and FT8 / FT4 / WSPR beacon. You can also use our CW-SigGen project to generate a suitable test signal.