Fire Tone Out Decoder Project Part One of ..

Quick Note: I completed this project in my blog- https://madscientisthut.com/wordpress/daily-blog/recording-scanner-traffic-using-python/
I have been wanting to build a Fire Tone Out decoder ( FTO ) for some time now. FTO is a two frequency tone set that assigned to each department, each pair of tones is unique. The FTO tones are played before the dispatch information is read out by the radio dispatcher. Pagers are programmed to recognize the tone set assigned when received then the pager starts to record any pertinent information.

When completed this project will allow me to monitor the dispatch radio traffic without having the audio playing until a department I am interested in hearing gets a tone out. Well I am finally getting around to starting this project and want to show you this project as I progress through it.

There are software and scanners out there that can be purchased to do this functionality but both are extremely expensive. I want to do this for less than 60 dollars and I think it can be done using a cheap Baofeng radio, an Arduino, a couple of Op Amps, some discrete parts, and a few voice recording modules, and to be fancy I could add an LCD display to show who was toned and other information. Who needs an expensive Uniden DMA scanner anyways...

In this first step of the project I used the fix_fft library to make a spectrum analyzer just to see if the Arduino Nano was capable of measuring the frequency range that I was interested in. The FFT code was easy enough to use, although I wanted smaller frequency bin sizes and it would have been nice to use a larger sample size than 256 samples, I tried 512 samples and the fix_fft code did not seem to handle this well the readings appeared to become random and the memory usage in the Nano was around 70%. I think I may investigate this further using an Arduino Mega later on. The next step will be for me to buffer the input with a non inverting adjustable gain, rail to rail, single supply voltage op amp. that way I can run a input to the circuit from a radio and adjust the input level as needed without worring about over driving the A0 analog input.

Видео Fire Tone Out Decoder Project Part One of .. канала Mad Scientist Hut