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.
[Photo credit: WSPR hompage]
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.
Continue reading “Hacking a Ham Radio”
As the year draws to a close, we must look back and look at the advances in amateur radio this year. The RTL-SDR tuner hack, a USB TV Tuner to create a software defined radio receiver, is one of the greatest hacks of the last 12 months and a great justification for 2012 being the year of software defined radio receivers. 2013 is shaping up to have even more advances in the state of software defined radio. This time we’ll be transmitting as well, possibly with [AE9RB]’s Peaberry SDR transceiver.
The Peaberry SDR transceiver is a kit to both transmit and receive on every HAM band between 160 meters (1.8 MHz) to 17 meters (18 MHz). It does this through a USB interface and a 48kHz, 24-bit interface that is (or will shortly be) compatible with all the major SDR interfaces.
While the Peaberry SDR requires an amateur radio license to operate, we can’t wait to see what else will be coming to the software defined radio scene in the next year.
Thanks [Zach] for sending this one in.
They sure don’t build them like that anymore. [J.W. Koebel] managed to take this 1934 Simplex Model P radio and bring it back to life.
So where do you start with a repair job like this one? Being a ham radio guy he has a good idea of what he’s doing, and started by replacing the AC capacitor with one which will provide quality noise filtering. He tried to make fixes throughout that would improve functionality and declutter the wire mess. This led him to find a snapped solder connection on the volume knob. Next he tested out the speaker and found that the primary transformer needed replacing. After as replacing the A67 converter (we’ve got no idea what that is) he swapped out the rest of the original capacitors, most of the resistors, and fixed the mechanical problems with the tuning dial. The result is a working radio that looks fantastic!
[Balint Seeber] just sent in a small yet timely project he’s been working on: a software radio source block for the Realtek RTL2832U. Now with a cheap USB TV tuner card, you can jump right into the world of software-defined radio.
[Balint]’s code comes just a week after hackaday and other outlets posted stories about using a $20 USB TV capture dongle for software defined radio. At the time, these capture cards could only write data directly to a file. With [Balint]’s work, anyone can use a cheap tv tuner dongle with HDSDR, Winrad, or GNU Radio. If you’ve ever thought about trying out software-defined radio, now might be the time.
Elsewhere on the Internet, a surprisingly active RTL-SDR subreddit popped up dedicated to using the Realtek RTL2832U tuner for software defined radio. There’s an awesome compatibility chart listing compatible USB dongles. The cheapest (so far, and subject to change) is the Unikoo UK001T available for $11 on eBay.
With his source block, [Balint] can listen to anything on the radio between 64-1700 MHz. The sample depth is 8 bits and the sample rate can be anything up to 3.2 MHz. You can watch [Balint] testing out his $20 GNU Radio rig after the break.
Continue reading “Working software-defined radio with a TV tuner card.”
With a simple digital TV USB capture card, you can build your own software defined radio or spectrum analyzer. While it may not be as cool as [Jeri Ellsworth]’s SDR, it’s still very useful and only requires $20 in hardware.
The only piece of hardware required for this build is a USB FM/DTV capture device with the Realtek RTL2832U chipset. So far, two USB sticks have been tested and the unit with the largest frequency range (64 – 1700 MHz) is available direct from China for $20.
Turning these cheap capture cards into software defined radios and spectrum analyzers was discovered by [Antti Palosaari] after sniffing the device. These cards demodulate the frequency and send all the data to the computer and is decoded via software. If you have one of these capture cards lying around, you can grab the software and load it up on your *nix box. Right now, the software only writes directly to a file, and may drop a few samples if writing to a hard disk instead of ram. Small problems, but we’re sure this project will pick up steam in the very near future.
[Mark] had seen a few examples of algorithmic music generation that takes some simple code and produces complex-sounding results. Apparently it’s possible to pipe the output of code like this directly to audio devices on a Linux box, but [Mark] decided to go a different direction. His project lets you play simple algorithms as audio using AVR microcontrollers.
Now the code work for this is very simple, but he hardware implementation is where things get interesting. Ostensibly, [Mark] didn’t have the components available to build a filter to use PWM as an audio signal. Being that he’s a ham operator, he grabbed some radio equipment he had on hand and whipped up an alternative. He’s feeding the PWM from an Arduino into the voltage controlled oscillator on a board meant for high-altitude balloon telemetry. The signal broadcast by this board is then picked up by his radio receiver, and played on some speakers.
Rube-Goldberg contraptions aside, the effect is pretty interesting, as you can hear in the latter half of the video clip which we’ve embedded after the jump.
Continue reading “AVR chiptune project turns this simple code into music”