Technically, the license granted by the FCC specifically disallows transmitting “data” on the family radio bands, which includes touch tones. But the odds of getting ‘caught’ are pretty much zero… I looked into using these for communication from weather balloons.

I doubt anyone technically cares if it is legal or not… All I hear on hackaday is:
1. Not a hack.
2. Arduino.
3. That’s not safe/ wear eye protection/ wear a helmet
4. That’s not entirely legal.

Where’s the true hacker spirit?

@Pilotgeek

Well, while the same old whines get tiring, but I didn’t know this was technically illegal and appreciate the warning.

When dealing with feds, ‘Safe keeps you alive. Legal keeps you employed.’

Really? ” Where’s the true hacker spirit? “? Honestly guys. How many of you have thought of this? He took something and though somewhat illigal made use of it in a different way it wasnt intended for. he improved upon it. He hacked it to do something. Just cause its not extreme doesnt mean its not hacking. I say well done.

This is awesome!

SO what frequency can we use, and would a mini balloon fited with sataelite hacked gear make transmission more powereful/clear line of sight in the woods (out of the city)

Sorry, some how I knew my comment would be misinterpreted… I should have stated right off, yes, cool project, even better writeup! I’m sure I’m not the only one who learned something from the write up. I was considering this for, well, not a commercial application, but a wide spread application where I thought paying attention to the rules would be a “good idea”. I would not hesitate to do this for a personal project, as there is pretty much zero chance anyone else would ever notice, more or less know the rules and report me. Oh, yea, and take the time to track me down :-)

So I didn’t mean to be negative, just wanted to point out some trivia for next time someone needs cheap, low power, disposable wireless communications.

@Paul Potter That’s not random, that’s Dvorak.

Neat hack. I’ll have to look for some cheap walkie-talkies, so I can try it out myself!

@Pilotgeek
you forgot:
5. But you can just buy one of those at __.

Defiintely neat, might be an excuse to check into FRS – Never really been a fan of it due to the legal restrictions on it though; 500mW max and no modifications allowed.

However, that said, getting an amateur radio license is easier than ever since they dropped the morse code requirement. Got my tech and general licenses a couple months ago, only took a couple hours of brushing up on theory and laws, followed by a $15 fee and a couple of simple multiple-choice tests.

Why did I mention that? FRS operates at around 467mHz, the closest legal band is 70cm, or 420-450mHz. Not sure what type of local oscillator these radios use (never had one to play with), but it should be possible to replace or modify the LO circuit, drop it into that band, and mess around legally (provided you’re licensed, you only need tech but general is easy enough to get)…Up the power to 5 watts or so (also relatively easy), and now you’ve got a usable system for RTTY based on ubiquitous, off-the-shelf hardware (except for the MCU, but they’re cheap enough)…

Wow. he’s a noob. Addd simple modem chips and get at leas 1200Bps without effort. if you really modify FRS radios you can get 9600bps easily.

We did this as a learning to hack at the detriot Hackerspace 2 years ago. It was pretty much effortless.

WE were able to do 1200bps with no hardware mods at all simply using the VOX functions and the soundcards in laptops as the modems. 9600bps was done in the advanced class.

Great hack! I’ve always wanted to do this. :)
I would love to hear how it sounds.

Don’t worry about the FCC.
I’m sure you won’t get in trouble as long as you don’t interfere with the important parts of the spectrum.

I’ve done this in the past using common AM7910 or AM7911 modem chips; there are more modern ones today of course, but they can be purchased cheaply at ham radio flea markets and the required circuitry is really simple.
Seriously, who cares if it’s illegal if it’s not clearly wrong. If you do everything you can to avoid jamming others transmissions going against the law is the way to achieve lighter regulations and progress. Think about CB and FM radio: they were were both illegal until people using them pushed for a less strict regulation.

@fartface

Yeah, what a total fucking noob. If he was really smart he would have just used a laptop with a wifi card, or an arduino with an xbee module.

I *real* hacker would have just used a 3G modem.

My first thought: …

wow … in democracy you are truly free, you can do any thing … NOT
( Communism was better … )

This is awesome.

@vtols 2.4 ghz is legal for data in the US (think bluetooth, wifi — though not limited to those two products). The 900 mhz range is also kind of a free-for-all in the US, but I don’t know if you can modulate data over it or not legally.

@Jaspel the same way your phones, wireless xbox controllers, and any other FCC approved devices do it: They use appropriate frequencies for their regions, (or buy them), and get FCC certified before they go to market.

@Gibson I’ve heard stories about the FCC knocking on friend’s doors, it DOES happen, they do NOT fuck around.

@mikey
Those operate on gmrs freq?

@vtols
You could use 2.4 GHZ “bluetooth, wifi, ZigBee” or 900 Mhz “ZigBee”
To get long range you could build a dish and tracking system with wifi. Use some servers to point and old DishTV Dish modified to use wifi. A USB wife dongle mounted at the receiver horn will work well.
Use GPS on the ground station and the balloon and then use some trig to keep the dish pointed at the balloon should work. I do not know if the gain would be too high and could be more then the FCC allows. If so get a HAM license and you should be good to go.
As I said this is a neat hack. Steve Ciarcia modified a Big Trak to get commands sent via a 300 baud modem through some kids walkie talkies back in the yearly 80s or late 70s. Of course he built his own 300 baud modem to do it. Since this was on CB it was also very illegal to do at the time but it got published in a national magazine.
This is still a cool hack and I feel very impressive.

I just want to say, it’s impressive that this guy is actually smart enough to wire up an MCU on a proto board. I hear lots of n00bs crying for arduino, that makes no sense. An arduino is good help for someone who doesn’t really understand how to construct the hardware, but this guy is clearly better than that.

Now, 10 baud? Blah. Lol. But hey, at least he tried.

This is a great hack. I’ve done similar with FRS packet radio software and acoustic coupling (as you had suggested). Cheap fm transmitters, cheap fm radios, packet radio software, and a soundcard are a way to do this without physical hacking and I believe there are no restrictions on sending data as far as I can tell. PSK31 can go quite a ways on low power.

I did the same thing a while back, except I just used the hands free port on the radio for the audio interface, and I used an XR2211 to demodulate the received audio. I was using it to transmit DGPS corrections at 300 baud to my GPS so that I could get 1M accuracy in my back yard.