Simple Voice Output of SWR and Power

We do not use a special IC but only the Atmel microcontroller ATmega644 which has just enough memory for the voice data. Together with a simple directional coupler made of two toroid cores the gadget is utilized by a blind OM.

Es wird kein Spezialbaustein benutzt, sondern lediglich ein Atmel-Mikrokontroller ATmega644, der gerade noch genügend Speicher hat, um die Sprachdaten darin abzulegen. Das Gerät wird seit längerer Zeit bei einem blinden OM eingesetzt zusammen mit einem einfachen Richtkoppler aus zwei Ferritringkernen.

Instead of special components only an AVR microcontroller ATmega644 is used. It has just enough memory to store the voice data. Together with a simple homemade directional coupler for maximal 100 Watts the gadget is used by a blind friend of mine since a long time. At present, however, the voice data are german. Sorry!

The program is written in C and uses the avr-libc. It consists of several parts: the main program swr.c and the voice data parts PGM_text_swr.c and the files in the directory Ziffer. They are included by the main program. Compile the program with the avr-gcc. The Makefile is only an example when using the avrdude and Atmels old AVR Starter Kit STK500.

Usage: Immediately after booting the microcontroller reads in the voltages at the forward and the reflected input (only once), calculates the values of SWR and power and ouputs the corresponding words. Then the device can be powered off again.