VFO-005

Schematic

Variable Frequency Oscillator (VFO) VFO

• Arduino Pro Mini
• AD9833 Function Generator
• Rotary Encoder/Breakout Board
• 128x32 OLED
• Breadboard Power Supply

AD9833 Function Generator

• • Digitally programmable frequency and phase
  • 12.65 mW power consumption at 3 V
  • 0 MHz to 12.5 MHz output frequency range
  • 28-bit resolution: 0.1 Hz at 25 MHz reference clock
  • Sinusoidal, triangular, and square wave outputs
  • 2.3 V to 5.5 V power supply
  • No external components required
  • 3-wire SPI interface
  • Extended temperature range: −40°C to +105°C
  • Power-down option
  • Update Rate: 25(max)
  • VOUT Maximum: 0.65V
  • VOUT Minimum: 38mV
  • VOUT Temperature Coefficient: 200°
  • Input High Voltage: 1.7-2.8V
  • Input Low Voltage: 0.5-0.7V
  • Input Current: 10µA
  • Input Capacitance: 3pF
  • Operating temperature range is −40°C to +105°C; typical specifications are at 25°C

Arduino Pro Mini

• 3.3V
• 8 MHz

Rotary Encoder/Breakout Board

• Includes pushbutton Switch
• Includes Pull-Up resistors
• Needs R/C filter on output for debounce
• Reading Rotary Encoders - Arduino reference
• Simple Rotary Encoder Arduino library
• Library for the Arduino environment for using a rotary encoder as an input

128x32 OLED

• Ebay
• 5V/3.3V operation

Breadboard Power Supply