Hardware and software for a CW (Morse Code) trainer ... Audio and visual.

The design goal is to make a stand-alone CW trainer.

Parts:

• Raspberry Pi -- any generation
  • SD card 4 GB or larger
  • Power supply
• Freenove Super Starter Kit for Raspberry Pi
  • About $22 on Amazon
  • Includes breakout board
  • LED and resistor
  • LCD screen with I2C controller
  • Potentiometer * 2
  • ADC chip via I2C
  • Speaker (passive buzzer with transistor driver)
  • LED matrix screen
  • Pushbuttons

Software:

• Raspbian OS https://www.raspbian.com
• pigpio library https://abyz.me.uk/pigpio/ or https://github.com/joan2937/pigpio

Installation

• Install raspbian OS
• Install pigpio
  • Need cmake sudo apt install cmake
  • From Github:

git clone https://github.com/joan2937/pigio
cd pigpio
mkdir build
cd build
cmake ../
make -j4
sudo make install
sudo systemctl start pigpiod.service
sudo systemctl enable pigpiod.service
sudo systemctl status pigpiod.service
cd ~

• Python module

pip3 install pigpio

• Enable I2c control
  • sudo raspi-config

• Uses simpleaudio module
  • Native methods in each platform
  • Monaural, 16 bit resolution
  • Sine wave with edge smoothing
  • numpy for calculating waveform
• Controls: pitch, volume in menu
• Works poorly at high speeds (Dits are lost)

• Uses GPIO pin from Pi header board:
• 
• Image from this reference
• GPIO 5 = Header pin 29 is used to LED with 10K resistor to ground