VFO-001

Features

• DD1306 OLED Display
  • I2C Interface
• Rotary Encoder Break Out Board
• STM32 (Blue Pill Board) Microprocessor
  • Arduino compatible
  • 3.3V
• Si5351 Oscillator Breakout Board
• 10 KHz - 40 MHz tuning range
  • 100Hz/1KHz/10KHz/100KHz/1MHz/10MHz steps
  • I2C Interface
  • 3 Outputs
  • 27 MHz crystal
• Extruded Aluminum Enclosure Box - 94mm x 83mm x 30mm

Schematic

Parts

Blue Pill Card

• Blue Pill Card

• 3.3V operation works without level shifters for I2C
  • OLED runs from 3.3V
  • Si5351 can only run from 3.3V
• Used right angle headers and Dupont cables for low profile
• Replaced BOOT 0,1 jumpers
  • Wire jumper on BOOT1
  • Switch on BOOT0 - easier to download code
• Download via serial
• Programmed via Arduino IDE

128x32 OLED

• Ebay

Libraries/Example Code

Land Boards Code

• Land Boards Application

Used in this app

• U8g2: Library for monochrome displays, version 2
• Si5351 Library for Arduino
• Rotary Encoder - Software debounced

Arduino Library for OLED

• U8g2: Library for monochrome displays, version 2
  • Reference library
  • Constructor

U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // STM32, Ebay OLED

• List of Fonts

  u8g2.setFont(u8g2_font_ncenB14_tr);

Hello World Code

U8G2_SSD1306_128X32_UNIVISION_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);   // STM32, Ebay OLED

void setup(void) {
  u8g2.begin();
}

void loop(void) {
  u8g2.clearBuffer();			// clear the internal memory
  u8g2.setFont(u8g2_font_ncenB08_tr);	// choose a suitable font
  u8g2.drawStr(0,10,"Hello World!");	// write something to the internal memory
  u8g2.sendBuffer();			// transfer internal memory to the display
  delay(1000);  
}

Others

• Universal Digital VFO Si570/Si5351
• Adafruit_Si5351
• Si5351 Library for avr-gcc
• vk3hn_VFO_controller
• Simple BFO with si5351 controlled by Arduino
• VFO and BFO with Si5351A, OLED and Arduino

Videos

• Charlie Morris YouTube channel