Radio Hacks

1438 Articles

Hammond Organ Sends Messages Which Can Be Decoded By A Spectrogram

March 28, 2013 by 6 Comments

hammond-organ-encodes-messages-spectrogram

Here’s an interesting use for an old organ. Let it get in on your Ham radio action. [Forrest Cook]  is showing off his project which uses a Hammond Organ to encode messages which can be displayed by a Spectrogram. We’ve seen this type of message encoding before (just not involving a musical instrument). It’s rather popular with Hams in the form of the fldigi program.

An Arduino was connected to the organ via a UNL2003 darlington array chip. This chip is driving some reed relays which make the organ connections to create the sine wave tones. With that hardware in place it’s a matter of formatting data to generate the target audio. [Forrest] wrote his own Arduino sketch which takes characters from the serial port (pushed over USB by the laptop), maps then to a stored 5×7 character font set, then drives the pins to produce the tones. As you can see in the clip after the break the resulting audio can be turned into quite readable text.

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Writing New Firmware For A Handheld Radio

March 22, 2013 by 12 Comments

HAM

When playing around with a cheap, handheld, dual-band radio, [Lior], a.k.a. [KK6BWA], found a schematic for a similar and even cheaper radio. He realized the programming pads were very accessible and the dev tools for the radio’s microcontroller were available from the manufacturer. After these discoveries, there really was only one thing to do: write new firmware for a $40 radio, and making a great tool for playing around in the 2 meter and 70 cm bands.

The instructions for reflashing the firmware on this radio only require an Arduino and a handful of miscellaneous components. [Lior]’s new firmware for the uv3r radio isn’t quite finished yet, but he plans on adding some really impressive features. Things like a better UI for a four-button radio, a mode for tracking satellites, a digital mode, and a computer-controlled mode are all possible and on [Lior]’s project wishlist.

Getting a $40 radio to do your bidding with an Arduino is cool enough, but [Lior] says this mod for the uv3r can be taken even further: if you’ve got an amateur radio license, it’s possible to use the uv3r to control an Arduino or other microcontroller from miles away. It’s a great hack, right up there with the USB TV tuner/software defined radio thing we saw almost exactly one year ago.

You can check out a demo of some custom software running on the uv3r after the break. The radio listens for a DTMF tone (supplied by the uv3r’s big brother, the uv5r), and plays back a three-digit DTMF tone. There’s also a more through walk through of what [Lior]’s new radio can do as well.

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WSPR Transmitter Shows True Value Of Raspberry Pi For Hacking

March 21, 2013 by 33 Comments

wspr

Don’t get us wrong, we love our Raspberry Pi. But if you’re merely running a Linux image without adding a hardware hack into the mix you’re missing out on part of the power for which the platform was developed. This project is a great example of how to embrace the Raspberry Pi’s ability to deliver both low-level hardware access, and solid embedded Linux performance. [Dan Ankers] and [Threeme3] have developed a program which turns the RPi in to a WSPR transmitter. The GitHub readme shares many of the details on how it was done. But you’ll also want to dig through the .c file to see how they’re making use of the GPIO header pins.

[William Meara] sent in the tip for this. He’s been featured on Hackaday previously for his work with WSPR (Weak Signal Propagation Report). It’s an amateur radio protocol which lets you communicate over very long distances using relatively weak transmitters. The trick is to use computing power to find the signal hidden in all the noise. Be warned that you do need a HAM license to try this out, but otherwise all you need to connect to the board is a low-pass filter and an antennae.

[via SolderSmoke]

[Photo credit: WSPR hompage]

Futaba 10C Radio Modified For Spektrum Module Compatibility

March 21, 2013 by 4 Comments

futaba-radio-modified-to-fly-spektrum

The Futaba 10C radio (non-module version) is [Tom]’s transmitter of choice. Unfortunately,  it isn’t compatible with the Spektrum DSM2 technology modules he wanted to use. So, being the crafty guy he is, he decided to hack it so it was.

Upon opening the Futaba transmitter, he realized that the non-module version of the 10C didn’t really seem that different than a module version. His transmitter just has a pcb hardwired in place where the modules would otherwise go. He soldered a 4 conductor audio jack to the unused pins on the pcb in the transmitter, then mounted it in the case with some J.B. Weld. He then wired and mounted the receiving jack in the module case. A small 6 inch audio cable bridges the two devices, and velcro holds them neatly together.

He discovered that certain modules have problems with the channels being out of order. Unless someone comes up with a firmware hack, there’s no way to remap the controls. So, some modules are just not compatible. [Tom] gives a very nice video walkthrough after the break. Check it out.

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UC Davis Students Build Coffee Can Radar Project Inspired By MIT

March 18, 2013 by 25 Comments

student-built-coffee-can-radar

Blinking lights is a lot of fun, but if you’re getting an EE degree the cool stuff becomes a bit more involved. In this case, building your own radar is the thing to do. Here’s a coffee can radar setup being shown off by a group of UC Davis students. Regular readers will recognize the concept as one we looked at in December. The project was inspired by the MIT OpenCourseware project.

One of the cans is being used as a transmitter, the other as the collector. The neat thing about this rig is that the analysis is performed on a PC, with the sound card as the collection device. The video after the break shows off the hardware as well as the results it collected. About a minute and a half into the clip they show a real-time demonstration where a student walks in front of the apparatus while another takes a video of the plot results. As the subject moves away from the receiver the computer graph changes accordingly. The rest of the video covers some operational theory and pcb assembly.

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Stealing Cars And Ringing Doorbells With Radio

March 14, 2013 by 25 Comments

The cheap software defined radio platforms that can be built out of a USB TV tuner aren’t getting much love on the Hackaday tip line of late. Thankfully, [Adam] sent in a great guide to cracking sub-GHz wireless protocols wide open, and ringing doorbells, opening cars, and potentially setting houses on fire in the process.

The first wireless hack [Adam] managed to whip up is figuring out how a wireless doorbell transmitter communicates with its receiver. [Adam] connected a FUNcube software defined radio dongle (although any one of the many USB TV tuner dongles we’ve seen would also work) and used GNU Radio to send the radio signals received to a WAV file. When looking at this audio file in Audacity, [Adam] saw the tell-tale signs of digital data, leaving with a string of 1s and 0s that would trigger his wireless doorbell.

The FUNcube dongle doesn’t have the ability to transmit, though, so [Adam] needed a more capable software defined radio to emulate the inner workings of a doorbell transmitter. He found one in the Ettus Research USRP, a software designed radio that’s doing a good job of keeping [Balint], Hackaday SDR extraordinaire, very busy. By sending the data [Adam] decoded with the FUNcube dongle over the USRP, he was able to trigger his wireless doorbell using nothing but a few hundred dollars of radio equipment and software ingenuity.

Doorbells are a low-stakes game, so [Adam] decided to step things up a little and unlock his son’s car by capturing and replaying the signals from a key fob remote. Modern cars use a rolling code for their keyless entry, so that entire endeavour is just a party trick. Other RF-enabled appliances, such as a remote-controlled mains outlet, are a much larger threat to home and office security, but still one [Adam] managed to crack wide open.

Hacking A Ham Radio

February 28, 2013 by 47 Comments

For Christmas, [Lior] received a Baofeng UV5R radio. He didn’t have an amateur radio license, so he decided to use it as a police scanner. Since the schematics were available, he cracked it open and hacked it.

This $40 radio communicates on the 136-174 MHz and 400-480 MHz bands. It uses a one-time programmable microcontroller and the RDA1846 transceiver. With the power traces to the MCU cut, [Lior] was able to send his own signals to the chip over I2C using an Arduino. He also recorded the signals sent by the stock microcontroller during startup, so that he could emulate it with the Arduino.

Once communication was working on an Arduino, [Lior] decided to get rid of the stock microcontroller. He desoldered the chip, leaving exposed pads to solder wires to. Hooking these up to the Arduino gave him a programmable way to control the device. He got his radio license and implemented transmission of Morse Code, and an Arduino sketch is available in the write up.

[Lior] points out that his next step is to make a PCB to connect a different microcontroller to the device. This will give him a $40 radio that is fully programmable. After the break, check out a video of the hacked radio in action.

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