Serial Port SDR

#1

Post by walterbell » Thu, Dec 06, 2018, 12:43 PM UTC

Re: Serial Port SDR

#2

Post by sorenjan » Thu, Dec 06, 2018, 12:58 PM UTC

Reminds me of using an output pin on Raspberry Pi to transmit FM radio: http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry...

Re: Serial Port SDR

#3

Post by rsp1984 » Thu, Dec 06, 2018, 1:45 PM UTC

Can someone with understanding of the matter ELI5 why this matters?

Re: Serial Port SDR

#4

Post by sokoloff » Thu, Dec 06, 2018, 1:45 PM UTC

sorenjan wrote: post #2

Reminds me of using an output pin on Raspberry Pi to transmit FM radio: http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry...

Used to good effect to in one step program and test the Kickstarter "Public Radio" devices. I thought that was neat:

https://www.kickstarter.com/projects/centerlinelabs/kickstar...

Re: Serial Port SDR

#5

Post by sokoloff » Thu, Dec 06, 2018, 1:46 PM UTC

rsp1984 wrote: post #3

Can someone with understanding of the matter ELI5 why this matters?

It doesn't really matter that much in any practical sense; it's just kind of cool.

Re: Serial Port SDR

#6

Post by cheschire » Thu, Dec 06, 2018, 1:48 PM UTC

Not being deeply into signals geekery, I had to lookup SDR. I believe the article is referring to a Software-Defined Radio.

https://en.wikipedia.org/wiki/Software-defined_radio

Re: Serial Port SDR

#7

Post by apo » Thu, Dec 06, 2018, 1:56 PM UTC

It sounds interesting. Beyond controlling RC vehicles, what would be some applications of software defined radios (SDRs)?

By the way, it looks like a USB-VGA dongle can be manipulated in a similar way:

https://news.ycombinator.com/item?id=16907260

Re: Serial Port SDR

#8

Post by walterbell » Thu, Dec 06, 2018, 1:58 PM UTC

rsp1984 wrote: post #3

Can someone with understanding of the matter ELI5 why this matters?

Hacking an object designed for A, to do B.

See: MacGyver

Re: Serial Port SDR

#9

Post by Fordec » Thu, Dec 06, 2018, 2:04 PM UTC

rsp1984 wrote: post #3

Can someone with understanding of the matter ELI5 why this matters?

Without having to hack and/or expose I/O pins, anything with a USB port that can run the open source code can be given wireless communication capabilities with a very common and cheap chip

Re: Serial Port SDR

#10

Post by lima » Thu, Dec 06, 2018, 2:05 PM UTC

> This alone is impressive, but [Ted] isn’t done yet. He realized that this method of transmission was generating some strong frequency harmonics which extended far beyond the theoretical maximum 1 MHz frequency of his UART SDR.

i.e., blast noise all over the spectrum. There's a reason why real transmitters are more expensive than a serial port adapter.

This kind of RF pollution is illegal for obvious reasons and if you manage to disrupt something important (emergency frequencies, mobile networks...), it's gonna be expensive.

Don't try this at home!