Theoretically, is it possible to make a radio transmitter with an Arduino?
Can't the current variations required to create radio waves be created by programming the Arduino appropriately? (Use the sine function and shit.)
>>950704
Why tho.
You can make an FM transmitter with a hand full of caps, a linear pot, a transistor, some thick ass copper to make an inductor and some perf board.
>>950704
You can. Not sure anyone has written libraries for it yet, but you could do it.
Of course, you'll still have to make an antenna, and it's going to be a very low power transmitter unless you send the output through an amp first. If you're going to need an external amp to make it worthwhile, why not just assemble the whole thing without an arduino?
>>950704
>Theoretically, is it possible to make a radio transmitter with an Arduino?
welll,,, any RF leakage is technically a 'radio' transmission
it does work as a TV signal generator (tho you need a type of TV no longer common in the USA)
http://tronixstuff.com/2011/05/30/tutorial-video-output-from-your-arduino/
if you wanna go software defined radio there are many platforms suitable.
arduino is not among them.
>>950728
What USB devices can be used to just output an electrical current level specified via software/code on a computer? I just need some simple, cheap device to start experimenting with. It also has to support high enough bandwidth to create radio waves.
>>950704
Maybe AM radio.
Clock speed is far too low for FM (16 MHz vs ~89-106 MHz).
Apparently a Raspberry Pi has a really useful side effect that lets you use it as an FM transmitter with no additional hardware:
http://hackaday.com/2014/06/15/easily-turn-your-raspberry-pi-into-an-fm-transmitter/
>>950769
There are SDR's (software defined radios), but an Arduino can't even toggle a pin on and off anywhere near fast enough for FM. Other microcontrollers may be able to do so, but will have to have a significantly faster CPU.
>>950704
I remember the days when kids made their radios out of transistors, capacitors and wires. Arduino and raspberry pi has done nothing but make everyone lazy when it comes to electronics. If you are going to use something as pre-made as arduino you may as well just buy a radio.
But why?
An arduino is like 20$
You can build one from scratch for like 2$.
Get a cristal oscilator, an op amp and an antena (copper wire).
You could even pair it with a reciver and have your own little radio convention.
Bada bing bada boom an AM radio transmitter.
I'll even throw in a schematic for both since im such a nice guy. With op amps you dont have to do any transistor biasing, Sure it limits your range but if your asking here im sure you don't have an FFC license in the first place.
FM is just as simple, but i found its kidna hard to get the resonance frequency to stay stable when it transmitts, if i put in the time and figure somehting out ill share.
>>951021
The reciver is a band pass filter designe.
XHz is defined buy the cristal oscilator and resonators you want to get. i use 8Mhz since they are the cheapest and avalable everywhere.
Now its important you get the right diode since the voltages are pretty low on the reciveing end and the diode needs to be quick enought to demodulate.
A 1N4148 is a silicone diode i think is still available eveywhere. Germanium works a lot better but i cant find any in my local stores so i asume they went extinct.
>>951021
But what if I want to make the transmission frequency variable? A crystal oscillator has a fixed frequency.
>>951067
Ok, than your need to build a tank circuit the old fashioned way, Inductors and capaciotrs. And to make it powerful enough you're gonan need a transsisot.
I even have your math here. The formulas are in metric however I dont do imperial.
You can use a 2N3402, though you are gonna need to bias it yourself. The inductor you can DIY out of some copper wire(bottom formula), or you can buy a pre made one. The latter is a bit more expenisve but will save you the trubble of aproxiamting its value, and thus make it easyer to pair wit ha capaciotr to make an LC circuit.
The values of the said componenets will define your frequency. (top formula)
I sugest you aim toward the AM band (550Khz - 1600Khz) since you can listen to it with an AM radio, unless you have a shotwave radio handy. also avoid building it on one of those metal sheet breadboards, they have a messy parasitic capacitance adn taht will throw your freqency off. Use a perf board.
