Arduino Becomes Superhet With A Little Help From Friends

October 10, 2021 by Al Williams 8 Comments

A radio receiver is always a fun project. [Jayakody2000lk] decided that his new superheterodyne design would use an Arduino and it looks like it came out very nicely. The system has four boards. An off-the-shelf Arduino, a Si5351 clock generator board (also off-the-shelf), and two custom boards that contain the IF amplifier and mixer.

The receiver started out in 2015 without the Arduino, and there’s a link in the post to that original design. Using the Si5351 and the Arduino replaces the original local oscillator and there have been other improvements, as well. You can see a video about the receiver below.

Tuning is by a rotary encoder and the current software lets you tune from about 4.75 MHz to a little over 15.8 MHz. Of course, you could change to any frequency the Si5351 can handle as long as the mixer and other components can handle it. The IF frequency is the usual 455 kHz.

If you decide to build this yourself, the design files are on GitHub. Overall a very nice and neat design. We are always amazed how little radio architecture has changed since Edwin Armstrong’s day. Of course, we have better components, even if they aren’t meant for radio purposes.

Continue reading “Arduino Becomes Superhet With A Little Help From Friends” →

Scrapped DVD Player Turns Into A Full Featured Clock

October 30, 2012 by Mike Szczys 14 Comments

[Dmitry] really went the distance with this project. It started as a broken DVD player scrapped for parts, and turned into this clock with way too many features. That link is a pretty a dry technical collection of the work. You’ll definitely want to have a look at it, but we’d suggest first watching the demo video after the break which is initially much more exciting.

The donor DVD hardware included a Vacuum Fluorescent display which is the nugget which [Dmitry] was after. But that board came along with some other nice things, like an integrated IR receiver. He also chose to use the PSU from the device. An Arduino is used to drive the clock. We’re not sure where he found it, but the video shows the service manual for the DVD player which must have a been a real help in interfacing with the display. The white dome on the right is a PIR motion sensor. It brings the device out of sleep mode when someone is in the room.

The case is laser-cut and started as cardboard to ensure everything fit as designed. The enclosure makes it a showpiece, but the features of displaying day, date, time, and temperature make it functional as well. Since the VFD is alpha-numeric we think this could even see future upgrades to be used as a new-mail/tweet/IM alert as well.

Get The Lead Out Of The Arduino Compile Process

September 13, 2011 by Mike Szczys 23 Comments

Relief is here from long compile times when developing firmware for your Arduino project. [Paul] was puzzled by the fact that every file used in a sketch is fully recompiled every time you hit upload–even if that file didn’t change. To make things more confusing, this behavior isn’t consistent across all Arduino compatible hardware. The Teensy has an additional feature not seen when working with other hardware boards in that it reuses previously compiled code if nothing has changed. It even tells you which files are being reused, as shown in the image above.

After the break we’ve embedded [Paul’s] video that walks us through the process of editing the Arduino IDE to reuse previously compiled files. It’s a one-liner addition to the boards.txt file. For example, if you’re working with the Arduino Uno all that needs to be added is ‘uno.build.dependency=true’. [Paul] had previously submitted a patch to roll this into the Arduino IDE source code, but it was not accepted citing a need for more testing. He’s asking for help with that testing and wants you to post your thoughts, or any bug information, on the new issue he’s opened regarding this feature. Continue reading “Get The Lead Out Of The Arduino Compile Process” →

The Transistor Takes On The Machine

November 7, 2010 by Jakob Griffith 3 Comments

It only took 4 hackerspaces, but we finally get to see a zombie movie inspired project; hackerspace The Transistor Takes on the Machine with a Dawn/Shawn of the Dead movie theme. Race cars disguised as zombies swarm toward the players, who then use laser tag like guns to “shoot” down the approaching undead. The whole thing is a mess of Arduinos communicating with xBees to a central iMac G3, but it all comes together rather well and is promised to be released open source.

Now all that’s left is deciding which hackerspace wins the competition. Who do you have your money on?

[Thanks Deven]