Have you ever wanted to create your own radio? If so, this tutorial is for you! In this article, we will create our own radio transmitter, based on a Raspberry Pi! Thanks to this tutorial you will be able to create at home your own small radio station at home.
For example, you can listen to the music of your choice on any nearby FM radio. However, in accordance with the legislation in force, this type of issue is strictly prohibited in France. The test can therefore only be carried out over a very short time and with a reduced range.
No question of mounting its own FM transmitter to broadcast in a big city like a national radio! In order to create your own radio transmitter based on Raspberry Pi, you will need a number of software PiFmRds and Soxas well as a number of equipment to create your transmitter. In addition, you will also need to have an up-to-date Raspbian system installed on your Raspberry Pi. The first step of our tutorial will be to create and install an antenna on your Raspberry Pi.
To do this, we will use a wire that will act as an antenna. Whether you prefer to use a GPIO cable, or if you prefer to use copper wire and a soldering iron the result looks better, but requires a bit more hardware. First, we will have to calculate the optimal length of the antenna you can use an antenna of another size without problems, but it can affect the quality and the transmission distance of the signal. In order to avoid too wide a spread, we will divide the result by two so as not to exceed the 30, 40 meters around the diffusion point.
Warning, the higher this point, the greater the distance. Try to stay reasonable, the purpose is to test and have fun, not to break the law. In our case, we will use the transmission frequency Once this length is divided by two, we obtain an antenna of about 8. Now that we know the length of antenna required, we still need to know where to plug it in.
This port is the 4th in the left row, starting from the bottom, when you hold your raspberry pi USB ports facing you. The antenna must be connected to the GPIO port surrounded in red on this image. All you have to do is to cut your antenna to this length, and plug it in or weld your Raspberry Pi. Once the antenna is connected, we will have to install the software to transmit radio waves via the antenna.
All you have to do is to test the FM band by default Direwolf provides the same result using the same hardware setup but with many more options smart beaconing, igate, digipeating and is much less taxing on the Pi's CPU. Most importantly, that project is actively maintained. Detailed set up instructions are also available.
As such, I'm no longer providing support for this project. This project idea has been in response to the more hardware heavy Raspberry Pi projects that involve extra TNC hardware, additional sound cards, and custom cabling. My criteria has been a Raspberry Pi and an HT as the two major hardware components. No hardware TNCs and no custom cabling.
The magic happens in the software. A Python based modem library and a relatively simple PHP script are the main components driving the project. Let's dig in. This setup uses Raspian.
I'm using an old Earthmate LT In order for the Pi to read the GPS data we'll install gpsd. Instead I'm using a simple Python library called afsk modem.
Install this using pip. Download the the main PHP script and place it in your Pi's home folder. You'll want to modify the first two variables entering your callsign and any extra message you want transmitted with your position. Reading in the GPS data, the script converts that to an APRS message string, runs the message through the modem library, outputs a WAV file and then plays the audio file through the Pi's onboard sound card.
There are several methods to run this script automatically at startup. My Raspberry Pi lives in my car and I've attached a mag mount antenna to the Baofeng for better reception. In the future I'd love to figure out a way to power the Baofeng from the car. Currently I have to take the HT in the house to charge every few days.
I also have to turn it on and off each trip to and from the car. Another potential upgrade may be a 12 watt amp to help improve packet reception in areas where IGates and Digipeaters are scarce. I tried the same setup with two different original Pis, but the stray RF passing through the audio cable was strong enough to override the HT's squelch, preventing the HT form transmitting.Be it a boring afternoon, a monotonous job or a lonely long drive FM radio stations have always kept us entertained.
Surprising enough with the help of Raspberry Pi it should hardly take less than half an hour to set up your own FM broadcasting station and get on air within a local area. With the help of a proper antenna you should be able to cover an area of 50m Radius which should be enough to broadcast within your school or locality. Interesting right!! Warning: This is an educational experiment and is not intended to be misused for causing trouble. Also it is an offense to interfere with local FM frequencies, so use this with responsibility.
We take no holdings for any mishaps. It is assumed that your Raspberry Pi is already flashed with an operating system and is able to connect to the internet. It is also assumed that you have access to your Pi either through terminal window or through some victual server like VNC. In this tutorial we will be using the putty terminal window to execute the program on Raspberry Pi. Every microprocessor will have a synchronous digital system associated with it which is used to reduce the electromagnetic interference.
So by writing a code to perform frequency modulation using the spread-spectrum clock signal we can tweak the Pi to work as a FM transmitter.
Raspberry Pi Radio Transmitter
We can simply attach a normal wire of 20 cm maximum to this pin to act as an antenna. If you already know how to reach your pi though Terminal window then skip this step, else read through.
When you enter the desktop of PI, search for network option and connect your Pi to your router. Then get into pi menu and select pi configuration and then enable allow SSH communication. Now install Putty and open it. Enter the IP address of the Pi and click on enter.
Create your home radio transmitter with raspberry pi
If everything is done right a terminal window will pop up asking for username and password. By default the username will be pi and the password will be raspberry. Enter it and press enter you will get the following screen. You can directly clone this page into your pi, compile the program and launch it if you know how to do it.
For others, just follow the steps below and you will be broadcasting your own audios in no time. Step 1: Create a New Folder directory inside which we will place all our required program files.
Raspberry Pi RC Transmitter Introduction
Since we have already moved in the directory, we can just run the below command to do the job and you should get the screen shown here. Step 3: The program that we just downloaded is a C code, so we need the suitable compilers and tools to compile this program and launch it. Use the following code to download compilers. Your screen will look like this below once the download is complete. Step 4: Now we have everything ready to compile the program. You program should get compiled and you will get the following screen.
Raspberry Pi Stack Exchange is a question and answer site for users and developers of hardware and software for Raspberry Pi. It only takes a minute to sign up. I'd like to use a Raspberry Pi to transmit send audio from the headphone jack using it as an input to multiple Bluetooth devices at once.
The purpose I have a tutorial for receiving already is to have multiple Raspberry Pi that receive the Bluetooth and output to the 3. Bluetooth uses what are called piconets. Each piconet is made up of at least one master and as many slaves as the bands will allow. No bluetooth device can be the master of more than one piconet but a bluetooth can be the slave of many. This means that what you are looking for can only be done where each headset is the Master of its own piconet and the device delivering audio is the slave of them all.
I've never tried it but I dont think the built in bluetooth for the RPi3 will handle this correctly, unless someone has come out with an epic package for that. The only thing i can think of that would work is a splitter, something designed specifically to act as the slave of multiple BT devices.
Like this one from Walmart or these ones from Amazon. Take care: a lot of them however, only work for two piconets, meaning two headsets. I don't know of any that do more, but id love to see one. The problem comes from managing the frequency hopping that must be done to maintain paired connection. The more connections the more managements it takes to make sure the chirps don't overlap.
And the master is the device that decides what clock to synchronize and what frequency schedule to maintain, further complicating things. Haven't looked at these in a while, so shop around, maybe the tech got better and there are some out there that will do more than 2?
Then I set up a short range radio transmitter and used this to supply as many headphones as i desired for an outdoor movie night against a brick wall. It was a blast and worked like a charm. Bluetooth is awesome and if you want to stick with it that's fine, but it wasn't designed for this. Just throwing it out there that technologies do exist that were designed exactly for this think car radio.
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Asked 2 years, 10 months ago. Active 2 years, 10 months ago. Viewed 6k times. Is this possible? Greenonline 2, 4 4 gold badges 14 14 silver badges 31 31 bronze badges. Robert Perry Robert Perry 43 1 1 silver badge 3 3 bronze badges.
Active Oldest Votes. Nalaurien Nalaurien 3 3 silver badges 7 7 bronze badges. Radio is great idea. Do you know of anything like that ear radio headphones that just outputs aux to headphone jack rather than being all-in-one so users can use their own headphones?
I've looked and couldn't find anything. So long as it connects to their radio, that is.After my wildly successful post How to turn your Raspberry Pi into an infrared remote controlwhich was mainly a list of various resources and instructions on how to record and replay infrared signals with the Raspberry Pi, I am writing the second instalment, on controlling RF devices with it.
It just arrived yesterday, and I spent a few hours last night researching how I could make it work and recording signals. You have to use a voltage divider two resistors, I used a 1K and a 4K, connected in the voltage divider configurationto drop the voltage.
I used the following Python two-liner to convert the protocol analyzer timings to a LIRC raw format they come with tabs by default, make sure you convert those to spaces in Notepad or similar before running this :. This enables me to control all four sockets with my Raspberry Pi simply and efficiently, making me a happy man. That is a pity, but I might get a different frequency receiver to try that.
To make remote controlling these devices easier, I wrote a simple HTTP server in Flask that I can access through a web interface and turn these on and off. Unfortunately, the latency was too much, so I am currently writing an Android app which I call Tungsten, look for it soon in a Play Store near you!
This workflow also allows you to publish your Tungsten panes along with your HTTP control server, so potential users can just point their device to your server and download the layout with the buttons and proper HTTP call URLs. If you want to be notified when my app launches, follow me on Twitteron Google Plusor subscribe to my mailing list below.
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Amateur F1 driver. Technology enthusiast. Single parent. The voltage divider schematic. Sample timings, replace protocol analyzer's tabs with spaces. Subscribe to my mailing list Did you like what you just read and want to be notified when I post more?
Tweet Share Share Share. Stavros Korokithakis Guy who likes computers.It allows you to transmit any audio content through the Raspberry Pi. Connect a jumper cable to header 7 of the Raspberry Pi, the jumper cable acts as the transmitter for Radio. This will download the python script that helps with the transmission Step 3 : Untar the file you downloaded. Type this into the terminal. Step 5 : Open your Radio App on your phone or if you still have a functioning radio tune to Mhz and then in your terminal type.
If everything went well you should now be hearing Star Wars sound track in your radio. In the next post we will learn how to make a playlist for the Raspberry Pi Radio Transmitter.
Make sure you read about your local laws before trying this hack. Do you mean that jumper cable connected to header 7 will be some sort of antenna? Any idea what might be causing this? I have a GPS radio antenna that is not being used for anything.
Would hooking that up increase the range at all or would I need a powered solution? A summary of how it works would be nice without having to go through the source code. What techniques are used to accurately modify the frequency of the MHz signal? Haw does the. Use PiFMPlay for mp3. Unless I am misunderstanding something. Also, what is the power output of this transmitter?
The range varies depending on the antenna. If you are using a jumper cable it will cover around meters. Combine your Raspberry Pi with […]. This site uses Akismet to reduce spam. Learn how your comment data is processed. SD Card. Type this into the terminal tar xvzf pifm.
How to Build a Raspberry Pi Radio Transmitter
Like this: Like Loading The jumper cable connected to header 7 will act as an antenna. Any cable should be okay.
What is the output power of the Raspberry Pi in mW? It uses one of his GPIO pins to generate the Radio waves More specific: The clock generator can generate square waves and now I am using this to 'send' in radio frequencies using some script downloaded on the internet.
If we approximate that the dirty square wave coming from the GPIO pin, is a sinewave, and at the same time assume the antenna is directly driven.Raspberry Pi Pirate Radio
Well, then as joan said. So the formula can be approximated to be:. But at the end of the day, how much transmitted power you really get on the air TPO depends on your antenna and how well the impedance is matched etc.
So the fact that this works at all is rather amazing Just horribly inefficient, as you can see below. Here you see how it is radiating all over the place, all the way up into GHz. Thus the actual energy transmitted to the exact frequency you want, is extremely small. Which is why you don't need to listen that much to all those trolls preaching about the FCC rules.
Given that the maximum 3V3 output of the Pi is claimed to be 50 mA that puts an upper limit of 3. Furthermore given that an individual gpio is said be harmed if you source or sink more than 16 mA that suggests an upper limit of Sign up to join this community. The best answers are voted up and rise to the top.
Home Questions Tags Users Unanswered. Asked 5 years, 2 months ago. Active 1 month ago. Viewed 4k times. Steve Robillard Fusseldieb Fusseldieb 51 1 1 silver badge 3 3 bronze badges. Are you doing this purely with software?!? Did not know that was possible. Anyway, I have an FM transmitter. If you can tweak things, I think the key is to ensure you have the power to reach what you want, but not beyond that, and to use a frequency that won't interfere with anything else.
Yes, it's only with software. Huh, neat. And I went and bought one BTW it is easy to make a pretty effective dipole antenna of whatever size from decent gauge speaker wire. But in fact that the RPi can only generate square waves, makes the Transmitter very noisy