 Hello, this video is part of a series. Be sure to check out the full playlist in the description of this video Well, we've accomplished what we were trying to do. We are able to send digital information From one computer to another using radio waves and getting a nice looking formatted output on the other end So we've completed our tasks, but let's look at other options We I was using you know, you know two-way walkie-talkie radios, but you can use anything We also looked at using a microphone and a speaker here in my hand I have a little FM transmitter you can get this so in your car You plug this into your phone or your mp3 player and you can now play You know your music through your FM radio if you don't have Bluetooth or a auxiliary input This is about ten dollars off Amazon. You can set it to a number of different channels You just find a place on your radio where there's no channel being broadcast You can say out this is unrealistic for what we're trying to accomplish because this can only transmit a couple of feet and If you were to somehow boost it you'd be breaking the law. You can't just be sending out Signals long range on these frequencies without a license But shortwave, you know through the room just for fun. We're gonna do that We're gonna take this and send it not to a regular radio I have in my car, but to this ten dollar SDR dongle with antenna and hopefully with a little software magic we'll be able to grab those radio signals and Put them into mini modems so we can decode the messages being sent first thing when you do though is generate some data to send I'm getting a little board of sending fake address and stuff So let's just let's just generate some data from my computer The tree command will give you a tree structure of directories. So I'm gonna give it my USR folder bin folder and we get this nice little tree here But if we do the same thing and we pipe it into mini modem dash dash transmit 110 and then I do f for file and I'll call this files.wave Do that Kill it after a few seconds and then I can list out that file here. Whoops list Files that wave and we can see that I generated a wave file if I list out on it again and Make it human readable we can see that in those few seconds I generated a wave file that is if you can read that 184 megabytes in size and if I go to play that file It is 33 minutes long already just from those three seconds of generating data to keep things simple for this test I'm just going to convert that to an mp3 and put it on my mp3 player M peg dash I for input file. I'll give it the files.wave and I will make the output files dot mp3 and In a matter of moments I will have an mp3 that I can put on my mp3 player now We need a software that we're going to be capturing this with and for this example I'm going to be using a program a GUI program called GQRX. Quickly check my package manager apt to search GQRX and you can see that we have a package. It says it's GQRX dash SDR And you can see that the description says it's a software defined radio receiver Let's go ahead and start that up. We agree with a nice GUI interface I'm going to click the play button up here. You can see the waves going. You can see that on that 86 86.0 on our frequency. You can see my settings here. I'm saying this to normal and WFM stereo. I think is getting me the clearest signal for this I'm going to set our FM transmitter to 89.9. That's what it turns on at and I'll plug it into my mp3 player here and Make sure my mp3 player is on back on our desktop application here I am going to scroll up to 89.9 and we can already see it showing up right here Actually lined up very perfectly and The audio is coming around good. You can always Resize this if you need to clarify and also adjust the squelch and other things off to the right-hand side of the screen Now on the bottom right of the main screen of GQRX You'll see your gain here, which is like your volume and then you have some options here You can actually play this across the network record it play the recordings and this last little saying tells you where you're going to save So you click that in this little box comes up You can see it's by default. It's going to save to your home directory Go ahead close that you can save it to a different directory if you'd like but for this I'm just gonna click record And I'm gonna record for a couple of seconds here. Let it go ahead and go Just so we can collect some data Once you've decided to record it enough you can go ahead and click the record button again and Now we can close GQRX now in our shell will navigate to the folder where we just saved again by default It's gonna be your home directory and if I list out the files I can do GQRX. Sorry GQRX and you'll see that it gives it a timestamp. So this is The recording it made GQRX It gives you a date and timestamp and the frequency you're recording at all in the name again If you record more obviously this would change And now if we were to take that and put it into mini modem Dash receive at 110-f file we're gonna get an error and what this error says is that the input stream must be one channel Not two because we recorded this as a stereo channel and probably could have changed that in QRX But really easy to change that we convert using FFM peg So we just FFM peg dash I for our input file which is our GQRX file then dash AC one for audio channel one and then give it an output name and Mini modem is going to want it as a wave file. So we'll just say I'll call one dot wave Go ahead and save that only took a second So again the entire command is the FFM peg dash I and then your input file name and then dash AC One to convert to audio channel one and give it an output file in this case a wave file at this point We should be able to say If I could type mini modem mini modem dash dash Rx for receive 110-f for file and get the file name which in this case is one dot wave Right there and when I hit enter you can see that we have some lines of text and this is the text that was sent So you see we record enough to get a couple of folders in the tree output And it will display it as a tree output because that's all plain text when you're using the tree command So we just transmit data from one machine to another in this case an MP3 player But it can be anything with an audio output Using an ff ff an fm transmitter, which was ten dollars on Amazon probably get one cheaper again That's that's just for fun. We can only transmit, you know, I Would doubt it'd be more than 15 or 20 feet with this maybe 30 feet you can hear some music but to get clear audio for something like this is not going much further and Again if you were to somehow like hook an intent to this to boost it, you know Probably gonna get in trouble But just did it as proof of concept today. We did it with a GUI program capturing that audio Converting it back to text using mini modem. I'm gonna see should be able to do that all in a one liner From the command line haven't done it yet if I can figure it out. I will definitely do a video on that I have definitely done Used shell commands to record to a way files just as we have I need to see if that command will allow me to pipe the audio output Directly into mini modem I'm pretty sure that I can figure out how to do that. So I do thank you for watching again This video is just for fun just kind of wrapping up things here with the radio transmission and data transfer Videos, I hope you enjoyed them gonna begin back very soon to just some very basic shell stuff And then in the new year, I will have a week or two probably on some Android stuff So I hope you're looking forward to that. I thank you for watching and as always I hope that you have a great day