A Raspberry Pi next to a small circuit board

An Inexpensive FM Receiver For The Raspberry Pi

September 7, 2021 by Chris Wilkinson 38 Comments

At this point, there are no shortage of impressive hacks for the Raspberry Pi. [Dilshan Jayakody] recently documented his experience in designing and building an inexpensive FM Stereo Receiver for the Pi platform, and the results are impressive.

Quite a few FM receiver projects center around the RDA5807 or TEA5767 ICs, however [Dilshan] has used the QN8035 by Quintic Corporation in his build. A handful of discrete components on a pleasing single-sided PCB is all that is needed to interface the QN8035 with the Pi’s I2C bus.

After demonstrating that the FM tuner could be, well, tuned at the command line, [Dilshan] then coded a smart looking GUI application that makes tuning a breeze. The software allows the listener to manually and automatically scan through FM stations, decode program service data, control the volume, and display the RSSI and SNR readings from the tuner.

As we reported earlier, FM radio is on a slow decline into obsolescence. This latest project isn’t aiming to break new ground, however its simplicity and inexpensive components are the perfect combination for beginner hackers and radio enthusiasts alike. More details can be found over on Hackaday.io. The schematic, source code and bill of materials can be found on GitHub.

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MC68k SBC with a monitor, keyboard and mouse

Motorola 68000 SBC Runs Again With A Raspberry Pi On Top

August 31, 2021 by Robin Kearey 30 Comments

Single-board computers have been around a long time: today you might be using a Raspberry Pi, an Arduino, or an ESP32, but three decades ago you might find yourself programming a KIM-1, an Intel SDK-85, or a Motorola 68000 Educational Computer Board. These kind of boards were usually made by processor manufacturers to show off their latest chips and to train engineers who might use these chips in their designs.

[Adam Podstawczyński] found himself trying to operate one of these Motorola ECBs from 1981. This board contains a 68000 CPU (as used in several Macintoshes and Amigas), 32 kB of RAM, and a ROM program called TUTOR. Lacking any keyboard or monitor connections, the only way to communicate with this system is a pair of serial ports. [Adam] decided to make the board more accessible by adding a Raspberry Pi extended with an RS232 Hat. This add-on board comes with two serial ports supporting the +/- 12 V signal levels used in older equipment.

It took several hours of experimenting, debugging, and reading the extensive ECB documentation to set up a reliable connection; as it turns out, the serial ports can operate in different modes depending on the state of the handshake lines. When the Pi’s serial ports were finally set up in the right mode, the old computer started to respond to commands entered in the terminal window. The audio interface, meant for recording programs on tape, proved more difficult to operate reliably, possibly due to deteriorating capacitors. This was not a great issue, because the ECB’s second serial port could also be used to save and load programs directly into its memory.

With the serial connections working, [Adam] then turned to the aesthetics of his setup and decided to make a simple case out of laser-cut acrylic and metal spacers. Custom ribbon cables for the serial ports and an ATX break-out board for power connections completed the project, and the 40-year-old educational computer is now ready to educate its new owner on all the finer points of 68000 programming. In the video (embedded after the break) he shows the whole process of getting the ECB up and running.

[Adam] made a similarly clever setup with a Commodore 64 and an Arduino earlier. [Jeff Tranter] recreated a similar 68000 development board from scratch. And a few years ago we even featured our own custom-built 68k computer.

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A Simpsons TV For A Golden Age

August 26, 2021 by Bryan Cockfield 17 Comments

While the pace of technology continues to advance at breakneck speed, certain things in the past are left behind largely subject to the whims of nostalgia. Televisions, for example, are lighter, cheaper, and bigger than they were in the early 90s, but they did have a certain design aesthetic that doesn’t exist anymore. Meanwhile, Simpsons episodes have been (arguably) on the decline since the golden age of the 90s, so [buba447] decided to combine these two facets of a nostalgic past into a custom TV that only plays these older Simpsons episodes.

Update: Now there’s a build guide.

The TV is 3D printed but takes design cues from CRT-based technology from decades past. It even has working knobs emblematic of that era as well. Inside the “television” is a Raspberry Pi which is hooked up to a small screen. The Pi powers up and automatically starts playing Simpsons episodes once it boots. There is a power button at the top of the TV which mutes the sound and also turns off the display. As an added touch, the display outputs in 640×480 resolution, which is also somewhat historically accurate, even if the TV itself is much smaller than its ancient relatives.

Of course, the TV only plays episodes from The Simpson’s first eleven seasons, which includes all of the episodes of The Simpson’s golden era (and a few extra) and omits those episodes from the modern era, which will please certain Simpsons fans as well. This actually isn’t the first time we’ve seen a 24 hour Simpsons device. This Pi-based build serves up Simpsons episodes nonstop as well, but sends them out over the airwaves instead.

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Psion Organiser with a Pico memory pack.

Proto-PDA Regains Its Memory With The Help Of A Raspberry Pi Pico

August 26, 2021 by Dan Maloney 2 Comments

Remember the Psion Organiser? If you do, chances are you were an early adopter, as the 8-bit pocket computer had its heyday in the mid-1980s. Things have come a long way since then, of course, but just how far is illustrated nicely by the fact that a Raspberry Pi Pico can stand in for the Psion’s original memory packs.

Like many of the early attempts at putting a computer in your pocket, the Psion II had removable modules, which were dubbed “Datapaks”. The earliest versions of the Datapaks were little more than an EPROM chip on a small PCB, and the technical limitations of the day plus the quirky way of addressing the memory made it possible for [Amen] to mimic a Datapak using a modern microcontroller.

The first version was a breakout board that extended out of the Datapak slot significantly, with a Pico, OLED display, SD card slot, and a bunch of pushbuttons. That prototype proved that the Pico was indeed fast enough to fool the Psion into thinking a legit Datapak was plugged in. [Amen] later refined the design by making a board that stuffs everything into the Datapak slot, with the exception of the OLED which still dangles out where it can be seen. He puts the faux memory to the test in the video below.

It’s great to see groundbreaking tech of yesteryear like the Psion being taken care of and returned to use. We’ve seen others try before; here’s a hack that uses a Pi to connect a Psion Organiser to the internet through its RS-232 serial port.

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How Do You Make A Raspberry Pi On A Stick?

August 24, 2021 by Michael Shaub 38 Comments

We agree with [magic-blue-smoke] that one of the only things more fun than a standard Raspberry Pi 4 is the Compute Module form factor. If they are not destined to be embedded in a system, these need a breakout board to be useful. Each can be customized with a myriad board shapes and ports, and that’s where the real fun starts. We’ve already seen projects that include custom carrier boards in everything from a 3D Printer to a NAS and one that shows we can build a single-sided board at home complete with high-speed ports.

[magic blue smoke] used this ability to customize the breakout board as an opportunity to create a hackable media player “stick” with the Raspberry Pi built-in. We love that this Raspberry Pi CM4 TV Stick eliminates all the adapters and cables usually required to connect a Pi’s fiddly micro HDMI ports to a display and has heat sinks and an IR receiver to boot. Like a consumer media player HDMI stick, all you need to add is power. Continue reading “How Do You Make A Raspberry Pi On A Stick?” →

Dedicated box to play new videos from a handful of content creators.

Dedicated Box Makes YouTube More TV-Like

August 20, 2021 by Kristina Panos 19 Comments

[Exposed Wire] is a huge fan of YouTube and consumes a lot of content. If that sounds familiar, maybe you should build a dedicated YouTube box, too. You get to push buttons, there’s LEDs, and you can take a break from other screens to look at this one for a while. [Exposed Wire] wanted to make it easier to watch the latest videos from their favorite creators, but we would argue that this is more fun, too.

The Rasberry Pi 4 inside checks every five minutes for new videos by keeping track of the creator’s total number of videos in a text file and doing a comparison. If one of the channels has a new video, then the corresponding LED lights up and the new video’s URL is linked to the button. Press the button and the Raspi opens the browser, goes the the URL, maximizes the video, turns off the LED, and updates the video count in the text file.

We like the construction job here. The 1/4″ MDF walls are connected by 3D-printed L-brackets in PETG. At first, [Exposed Wire] mounted the LEDs and buttons to a PCB, but that was really fiddly so they printed panels instead. Combined with the bracket around the screen, the finished build looks good. Check out the build montage after the break.

Regular old YouTube videos not doing it for you anymore? Try watching them at low resolution on an LED matrix.

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Raspberry Pi Powered Standing Desk Rises To New Heights

August 18, 2021 by Matthew Carlson 15 Comments

Like many office workers, [David Kong] found himself the lucky recipient of a motorized sit-stand desk. Also like most office workers with such a desk, he found himself mostly sitting. Reminders on his phone did little to change habits and [David] resolved to automate his desk to rise on a schedule.

Taking off the front panel of the control box required a few screws and [David] was delighted to find some testing pins right on the PCB.By connecting the right pins together, he could simulate any button being pressed. A Toshiba TLP222A solid-state relay made it simple to connect the pins together, the next step was triggering the relay on some sort of timer.

Speaking of timers, the oft-lauded 555 timer was considered. However, the length of time desired wasn’t as well suited for the 555, and the appeal of just tweaking a file to adjust the interval was tempting. Going to the other end of the spectrum, [David] had a Raspberry Pi zero laying around he had been meaning to play with.

After soldering the relay to pin 17 and writing a quick 10 line python script that is executed on startup, [David] had a working solution that could be taped to the underside of the desk, out of sight. Rather than being on a fixed timer, the desk raises every 45 to 60 minutes. The impact on his life has been wonderful, which was the goal of this particular project. It’s been a few months and he hasn’t had to tweak or fix anything. Is a whole 64-bit multicore processor a bit of an overkill for toggling a pin every hour or so? Yes. But we can’t really fault him for reaching for what was already lying around. The results speak for themselves.

Perhaps this would be something you would incorporate when you’re building your own standing desk?