Retro-fit old radio with Arduino and FM module

“You can’t put new wine in old bottles” – so the saying goes. But you would if you’re a hacker stuck with a radio built in 2005, which looked like it was put together using technology from 1975. [Marcus Jenkins] did just that, pulling out the innards from his old radio and converting it to an Arduino FM radio.

His cheap, mains powered radio was pretty bad at tuning. It had trouble locating stations, and tended to drift. One look at the insides, and it was obvious that it was not well engineered at all, so any attempts at fixing it would be pointless. Instead, he drew up a simple schematic that used an Arduino Nano, an FM radio module based on the TEA5767, and an audio amplifier based on the LM386.

A single button on the Arduino helps cycle through a range of preset frequencies stored in memory. The Arduino connects to the FM radio module over I2C. The existing antenna was connected to the TEA5767 module. The radio module outputs stereo audio, but [Marcus] was content with using just a mono channel, as it would be used in his workshop. The audio amplifier is pretty straightforward, based on a typical application found in the data sheet. He put it all together on proto-board, although soldering the FM radio module was a bit tricky. The Arduino code is quite simple, and available for download (zip file).

He retained the original tuning knob, which is no longer functional. The AM-FM selector knob was fitted with a micro-switch connected to the Arduino for selecting the preset stations. Almost everything inside was held together with what [Marcus] calls “hot-snot” glue. The whole exercise cost him a few Euros, and parts scavenged from his parts bin. A good radio could probably be had for a few Euros from a yard sale and much less effort, but that wouldn’t be as cool as this.

Go deeper and explore how FM signals are modulated and demodulated for playback.

A new method for adding audio input to a Sansa Clip+

The Sansa Clip+ is a nice little MP3 player and recorder. But it doesn’t offer an input connector, instead relying on the built-in microphone. [Simon Frank] wanted to extend its functionality so he figured out how to add a standard audio jack for analog input.

This is not the first time this has been done, but [Simon] has found a different method of accomplishing the task at hand. The other external input hack we saw cannibalized the internal microphone, rerouting its connections as an external input. But the method seen here keeps that microphone intact. The device includes an FM radio chip which is attached to an ADC on one of the devices other integrated circuits. [Simon] just patched into those signals. Now all he has to do is set up the device to record from the radio and connect his source to the jack which he epoxied to the base of the enclosure.

Makita jobsite radio gets a few extra bells and whistles

[Jose] added several features to a Makita AM/FM jobsite radio, and did such a good job that you can’t tell they weren’t originally part of the design. The original radio has a compartment for a battery pack used with Makita’s line of rechargeable tools, and offers AM/FM radio, as well as auxiliary audio playback via a pair of speakers. [Jose] augmented those speakers by adding a pair of tweeters as well.

Next on his list of features were a couple of power bus add-ons. In the image on the right you can see the results of adding an automotive cigarette lighter to the side of the unit. Opposite this you’ll find a pair of USB ports that are activated by a lighted toggle switch. The ports are part of a USB car charger that is patched into the battery with a flip of that switch.

Finally, there’s a built-in Bluetooth audio receiver that connects to the auxiliary input. As shown in the image on the left, he can now play tunes from his cellphone without the need for a cord. See him showing off the device in the video after the break.

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Over-the-air FM radio gains Internet control

[Old bit collector] is giving up control of his radio dial to the Internet. He combined a couple of Parallax products which now allow him to tune, adjust volume, and toggle the power for an FM radio receiver.

The setup is pretty simple. An FM receiver module is mounted in the breadboard seen above which helps to break out its control pins. Those are connected to a Parallax Spinnarette web server board. It’s auxiliary I/O pins are controlled via a web interface that he set up and plans to operate with the browser on his Android phone. But as you can see after the break, any web browser works as long as you know the correct address.

This is pretty good if you’re on a quest to make everything controllable from your smart phone. But we would love to use the concept to make our own streaming radio. You’d be able to tune in to all of your local stations from anywhere in the world.

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