Author: Tim Molteno (ZL4TCM)
Some very basic radios, developed as a way to learn about radio.
Very basic radio project. It uses the CH32V305RBT6 RISC-V microprocessor (http://www.wch-ic.com/downloads/CH32V20x_30xDS0_PDF.html). It has the following features made by Nanjing Qinheng Microelectronics Co.
- 144 MHz 32-bit RISC-V core (IMAFC instructions)
- Single cycle multiply and hardware division (FPU)
- 64K SRAM
- 4 Op Amps
- 2 x 12-bit DAC !MHz (Dual Channel Mode available for Baseband)
- 2 x 12-bit ADC 1MHz
Reference manual (http://www.wch-ic.com/downloads/CH32FV2x_V3xRM_PDF.html)
Set of RISC-V instruction extensions.
Integer (M) multiply and divide. Atomic (A) instructions Floating Point (F) single-precision Compressed (C) instructions.
A local oscillator with I/Q outputs.
A switching I/Q mixer to zero IF.
40 dB LNA on Antenna Input for RX.
DAC I,Q -> MIXER -> HPF -> PA
SPI OLED screen, LED, Button1, Button2, Morse Key. Beep through speaker.
Set LO to 50 MHz.
Button 1. Increase f Button 3. Decrease f, Button 3 ON. Tx on (beep)