A CW DECODER
Another very useful project for Morse Code practice, as well as reading code in from a rig output or through the internal microphone (I added this to the original project) is the CW decoder designed by Francesco Morgantini, IK3OIL. Featured in the August 99 issue of QST, this project uses the PIC16F84 microcontroller and it must be programmed with the file 'CWTOOL.HEX' available at www.arrl.org/files/qst/qst-binaries/ (contained within the file ik3oil2.zip found there). The original article is available at the 'Members Only' section of the ARRL website, or might be obtained from someone with back-issues of QST magazine.
Not visible in the picture is the HD 44780 based LCD display under the homebrewed main circuit board for the project.
The programmer which I built for the 16f84 chip was designed by Ludwig Catta, and is found in figure 2 of the 'Using PIC Microcontrollers in Amateur Radio Projects' article, October 98 QST. My unit is shown below.
The software
for loading the cwtool.hex file into the PIC is
called 'PIX', and is located (per the PIC programming article, note 15) at
http://home5.swipnet.se/~w-53783/.
A problem was encountered in trying to locate the 4093 CMOS quad-nand gate, so I used a 4011 which, initially would not oscillate for code practice. The slight modification I came up with is shown below, and works well ( this is the original circuit, with the change of U2 and C7 shown as needed).
My decoder has been in use for about 7 months now, and is very good for straight key practice as it demands almost perfect character formation to give a display of what was intended to be sent.