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hi and welcome so I'm in the process of reviving this channel and I wanted to start some series on some interesting topics which will probably most likely be in wireless communications or digital signal processing and I figured that doing a few videos with canoe radio would be a pretty good place to start so this will be the first in hopefully a series of videos on new radio and we're going to start off with probably the most simple thing you can create which is an FM transmitter so the hardware that I'm gonna use in this example is a hack RF and we're going to configure the hack RF as an FM transmitter using this software that have opened right here which is good new radio and it's a free and open source and pretty easy to use toolkit contains a lot of cool signal processing blocks that you can use to configure your software-defined radio so we're gonna start off by just creating a simulation of the transmitter and then after we verify that the simulation works we are going to move on to creating the actual transmitter and then later on in this video I'll show you a demonstration of it being used when you start a new project in new radio you'll automatically have these two blocks here up in the top left corner so this one imports all the libraries that we'll need to set up the new radio environment and so we can double click on it and in the general tab we can look at some of the various options that we can change we're actually gonna change the generate options to WX GUI then for each block you can go to the generated code tab and see the actual Python code that is generated when you place this block down so let's hit apply and okay this block here is a variable and we can double click to set the variable name and its value and we'll keep this at the sampling rate but we will change it to 40 4.1 K which is the sampling rate of the audio file that we're going to be transmitting hit apply and ok because we're gonna transmit an audio file that I have saved on my computer here we're going to need to use a file source so over here on the right we have all the blocks that we can use in let's go to core audio and then go down to WAV file source and then double click and just paste whatever the location of your audio sources press apply and ok and so this generates our audio source but I found that gimme radio doesn't tend to like it if you just use this alone there's a lot of distortion a workaround for this is to use an audio source as well so drop that down change the sampling rate to forty four point one kilohertz press apply and then we're basically just gonna add these two sources together but we're gonna multiply the audio source by zero so that it gets canceled out in the summation so let's go down to math operators multiply constant and note that the output of the audio source is orange and the input of the multiply constant is blue so the color of these signifies the datatype being used so orange is a float blue is a complex number so we need to match them so let's double click change to float press apply and okay and then we can connect them up and then let's also drop an ad block again change the data type to float and then we can connect our two sources together and this basically just generates our audio source so now we need to modulate the signal so let's go down to modulators wideband FM transmit drop that connect that up and then let's double click and the audio rate is going to be samp rate that's the variable that we set a moment ago and then do the same thing for quadrature rate and hit apply and okay so notice that the audio rate and the quadrature rate here on the on the transmit they're red and so it's giving us a data type error so let's go back into the variable a separate variable and this value actually needs to be cast as an integer so let's just put it at the beginning and there so the error goes away but before we transmit we're going to up sample the signal so let's go into resampler x' rational resampler and then let's up sample by 100 so next we are ready to transmit so for sake of simulation let's put a channel model in between the transmit and receive just to kind of add a noise floor so in channel models click channel model and connect that up and so this is a good time to actually use a slider variable so in channel model notice that there's a noise voltage we can actually set this to a variable let's call it a noise press a fly then in GUI widgets let's go to WX slider drag that double-click let's set its ID to the variable named noise set the default to 0 the minimum to zero and then the maximum value to 1 so when we run this this will give us a slider that we can adjust to play around with the noise in the channel model so that's more or less it for the transmitter now we can just put together the receiver and that's pretty much just doing the reverse of what we just did so we need to grab another resampler because we're going to down sample it by 100 so instead of interpolation I said that once at decimation to 100 next we're gonna go back into modulators and grab the wideband FM receive drop that then we're going to go back into math operators and grab a multiply constant and we're gonna use this as a volume so double-click set that to a float connect that up and again let's actually use a slider for this so let's set the constant to ball press ok let's grab copy and paste another gooey slider double-click the name to ball the default value will be 1 the minimum value will be 1 and let's set the maximum to 10 it fly next let's go back into audio grab an audio sync connect that to our multiply constant and so that's already set to the sampling rate and you can leave device name blank if it's empty then it will just set the default device and then let's drop in to FFT plots in instrumentation WX WX GUI FFT sync let's drop two of those one will show the receiver but we need to set it to a float connect that up to multiply constant then let's set this other FFT up to the output of the transmit so before we can run this it looks like there are some errors and you receive so I forgot to set the quadrature rate so that will just be Sam great and then the audio destination set that to one since we don't want a down sample press ok and then another thing is in the wideband FM transmit double click that and change the max deviation to 5000 and of 75,000 and the audio should sound a little bit better and that's it so now we can hit run up here our ancestors understood origins by extra so this plot appeared this shows what is being transmitted it's the spectrum being transmitted and then down here is be modulate the plot so we can adjust the noise product with this slider right here you can floor on the receiver and then we can also adjust the volume right here on this land but older than our written or oral records and nowhere very different from places that we know we've tended in our cosmologies to make things familiar despite all our that's the simulation now to do this on hardware is actually even simpler we can get rid of everything after the channel model including the channel model let's keep the irrational resampler then we need to drop the hack RF sync in my new radio the sync is not in a specified tree so it's in this no module specified in sinks then osmocon sync drop that connect that to the resampler now double-click and we need to set the correct sample rate we are taking the sample rate and we're up sampling it by 100 so we need to multiply sample rate by 100 here on this frequency we can set which frequency we're gonna transmit on I'm gonna transmit on the 152 megahertz and this is within the ham radio band so you will need a license to transmit on this frequency band so just keep that in mind and then hit apply alright so here's the setup we have a hack RF plugged into the computer which is running the flow chart that we just created and then here on the receiver there's this bough thing which is tuned to 152 megahertz and I can just hit play now it's transmen origins by extrapolating from their own experience how else like I said hopefully this is the first video in a series of similar videos using canoe radio and hack RF and other STRs currently I'm planning the next video to be on digital audio and then digital messaging sending images between SD ours and streaming video so I'll be working on those and well for now let me know if you have any questions down in the comments and thank you for watching