|This project describes the construction of a real "QRP"
keyer with a small microcontroller (PIC 16F84, with slightly modified hardware
also PIC16F628). This keyer features:
- variable CW speed, adjustable via poti from 20 to 300 letters per minute
- two message-memories (50..64 letters), each controlled by a pushbutton
- command mode only required for setup and more complex features
- special modes like "endless" calling loop and automatic contest number generation
- very low power consumption: 50..200 uA at 2.4 V supply when active, < 1 uA in standby mode
- simple circuit, can be built on PCB with less than "half matchbox size"
- dash/dot-memory can be turned on and off ("Iambic mode A" and "B")
- originally designed for a PIC16F84, but firmware also available for PIC16F628 (not -A yet)
- Controller is clocked by a built-in RC-oscillator with only 50kHz clock frequency (PIC16F628: 37 kHz)
- piezo speaker can be connected to the "sidetone" output (audio signal)
- optional, adjustable 'transmit delay' for the begin of an over (between PTT- and Morse keying output)
More about the PIC-Keyer...