arduino

2910 Articles

Altoids Tin Network Analyzer

February 9, 2015 by 16 Comments

Network Analyzers are frequently used for measuring filters, making them extremely valuable for building radios and general mucking about with RF. They are, however, extremely expensive. You can, however, build one in an Altoids tin with an Arduino Nano, a small screen, and an AD9850 frequency synthesis module picked up on eBay.

The basic idea behind a network analyzer is to feed a frequency into a device, and measure the amplitude coming out of the device, and plot this relationship over a frequency. [Bill Meara] has been a human network analyzer before, changing frequencies and plotting the output of devices under test by hand. [DuWayne] (KV4QB) build a device to automate the entire process.

The block diagram is easy enough – an AD9850 sends a signal to the device, and this is measured by the Arduino with a small amplifier. The signal is measured again when it comes back from the device under test, and all this is plotted on a small display. Simple, and [DuWayne] is getting some very good readings with a lowpass filter and crystal filter made on a small solderless breadboard.

Pac Man Clock

Pac-Man Clock Eats Time, Not Pellets

February 5, 2015 by 21 Comments

[Bob’s] Pac-Man clock is sure to appeal to the retro geek inside of us all. With a tiny display for the time, it’s clear that this project is more about the art piece than it is about keeping the time. Pac-Man periodically opens and closes his mouth at random intervals. The EL wire adds a nice glowing touch as well.

The project runs off of a Teensy 2.0. It’s a small and inexpensive microcontroller that’s compatible with Arduino. The Teensy uses an external real-time clock module to keep accurate time. It also connects to a seven segment display board via Serial. This kept the wiring simple and made the display easy to mount. The last major component is the servo. It’s just a standard servo, mounted to a customized 3D printed mounting bracket. When the servo rotates in one direction the mouth opens, and visa versa. The frame is also outlined with blue EL wire, giving that classic Pac-Man look a little something extra.

The physical clock itself is made almost entirely from wood. [Bob] is clearly a skilled wood worker as evidenced in the build video below. The Pac-Man and ghosts are all cut on a scroll saw, although [Bob] mentions that he would have 3D printed them if his printer was large enough. Many of the components are hot glued together. The electronics are also hot glued in place. This is often a convenient mounting solution because it’s relatively strong but only semi-permanent.

[Bob] mentions that he can’t have the EL wire and the servo running at the same time. If he tries this, the Teensy ends up “running haywire” after a few minutes. He’s looking for suggestions, so if you have one be sure to leave a comment. Continue reading “Pac-Man Clock Eats Time, Not Pellets” →

Sentiment

Display Your City’s Emotional State With Illuminated Snow

February 5, 2015 by 8 Comments

[Hunter] wanted to do something a bit more interesting for his holiday lights display last year. Rather than just animated lights, he wanted something that was driven by data. In this case, his display was based on the mood of people in his city. We’ve seen a very similar project in the past, but this one has a few notable differences.

The display runs off of an Arduino. [Hunter] is using an Ethernet shield to connect the Arduino to the Internet. It then monitors all of the latest tweets from users within a 15 mile radius of his area. The tweets are then forwarded to the Alchemy Sentiment API for analysis. The API uses various algorithms and detection methods to identify the overall sentiment within a body of text. [Hunter] is using it to determine the general mood indicated by the text of a given tweet.

Next [Hunter] needed a way to somehow display this information. He opted to use an LED strip. Since the range of sentiments is rather small, [Hunter] didn’t want to display the overall average sentiment. This value doesn’t change much over short periods of time, so it’s not very interesting to see. Instead, he plots the change made since the last sample. This results in a more obvious change to the LED display.

Another interesting thing to note about this project is that [Hunter] is using the snow in his yard to diffuse the light from the LEDs. He’s actually buried the strip under a layer of snow. This has the result of hiding the electronics, but blurring the light enough so you can’t see the individual LEDs. The effect is rather nice, and it’s something different to add to your holiday lights display. Be sure to check out the video below for a demonstration. Continue reading “Display Your City’s Emotional State With Illuminated Snow” →

ArduinoCamera

A Single Pixel Digital Camera With Arduino

January 31, 2015 by 29 Comments

[Jordan] managed to cobble together his own version of a low resolution digital camera using just a few components. The image generated is pretty low resolution and is only in grey scale, but it’s pretty impressive what can be done with some basic hardware.

The heart of the camera is the image sensor. Most consumer digital cameras have tons of tiny receptors all jammed into the sensor. This allows for a larger resolution image, capturing more detail in a smaller space. Unfortunately this also usually means a higher price tag. [Jordan’s] sensor includes just a single pixel. The sensor is really just an infrared photodiode inside of a tube. The diode is connected to an analog input pin on an Arduino. The sensor can be pointed at an object, and the Arduino can sense the brightness of that one point.

In order to compile an actual image, [Jordan] needs to obtain readings of multiple points. Most cameras do this using the large array of pixels. Since [Jordan’s] camera only has a single pixel, he has to move it around and take each reading one at a time. To accomplish this, the Arduino is hooked up to two servo motors. This allows the sensor to be aimed horizontally and vertically. The Arduino slowly scans the sensor in a grid, taking readings along the way. A Processing application then takes each reading and compiles the final image.

Since this camera compiles an image so slowly, it sometimes has a problem with varying brightness. [Jordan] noticed this issue when clouds would pass over while he was taking an image. To fix this problem, he added an ambient light sensor. The Arduino can detect the amount of overall ambient light and then adjust each reading to compensate. He says it’s not perfect but the results are still an improvement. Maybe next time he can try it in color.

Kill Time Making Flappy Bird, Not Playing It

January 30, 2015 by 12 Comments

With all the Flappy Bird clones floating around in the ether after the game’s unexpected success, there are some that are better than others. And by better, we mean, hacked together from misc hardware. If you’ve got an Arduino on hand, then you’re half way to making your own:

The “Minimalist” Version

[aron.bordin] created his own Flappy Bird game with a short list of parts some of us likely have lying around on our bench. An Arduino loaded with the appropriate code is wired to a 16×16 LED matrix, which apparently displays the minimal amount of visual information you’d need to play the game. The only other parts required are a single pushbutton and resistor tethered on a breadboard to control your flapping. With the wire hookup laid out by convenient diagrams and the libraries required for the code all found on the same page, this is easily something one could bang out in an afternoon. If afterwards you still find yourself with more time to kill than you can stand to play Flappy Birds, there is always the option of fashioning a humorously-sized cell phone case to squeeze it all into… which we’d like to see.

The “Fancy” Version

If you want more resolution than solid colored LEDs, or you just have a fondness for the terrifying bird abstraction the game is known for, you can switch out the 16×16 matrix for a Nokia LCD screen. [Huy’s] rendition of this build over on Hackaday.io will deliver a “more detailed” graphic for the game, and is still roughly just as easy to assemble. Similarly, an Ardunio is loaded with the smarts required to generate the game, along with a single pushbutton tacked on for control. The code and the daunting (/sarcasm) two steps needed to wire the Arduino to the screen can be found on his project’s page.

If you must kill boredom playing Flappy Bird, there is no excuse not to do so on something you made yourself.

Continue reading “Kill Time Making Flappy Bird, Not Playing It” →

Digitally Controlled Circuit Bending

January 30, 2015 by 16 Comments

Circuit bending doesn’t get a lot of respect around some parts of the Internet we frequent, but there is certainly an artistry to it. Case in point is the most incredible circuit bending we’ve ever seen. Yes, it’s soldering wires to seemingly random points on a PCB, but these bend points are digitally controlled, allowing a drum machine to transform between bent crunchiness and a classic 1980s drum machine with just a few presses of a touch screen controller.

All circuit bending must begin with an interesting piece of equipment and for this project, [Charles], the creator of this masterpiece of circuit bending, is using a Roland TR-626, a slightly more modern version of the TR-606, the percussive counterpart of the infamous TB-303. The circuit is bent in the classical fashion – tying signals on the PCB to ground, VCC, or other signals on the board. [Charles] then out does everyone else by connecting these wires to 384 analog switches controlled by an Arduino Mega. Also on the Arduino is a touch screen, and with a slick UI, this old drum machine can be bent digitally, no vast array of toggle switches required.

[Charles] has put up a few videos going over the construction, capabilities, and sound of this touch screen, circuit bent drum machine. It’s an amazing piece of work, and something that raises the bar for every circuit bending mod from this point on.

Thanks [oxygen_addiction] and [Kroaton] for sending this one in.

Continue reading “Digitally Controlled Circuit Bending” →

TeaSteeper

Automated Tea Maker

January 28, 2015 by 17 Comments

[Pariprohus] wanted to make an interesting gift for his girlfriend. Knowing how daunting it can be to make your own tea, he decided to build a little robot to help out. His automated tea maker is quite simple, but effective.

The device runs off of an Arduino Nano. The Nano is hooked up to a servo, a piezo speaker, an LED, and a switch. When the switch is turned to the off position, the servo rotates into the “folded” position. This moves the steeping arm into a position that makes the device easier to store and transport.

When the device is turned on to the “ready” position, the arm will extend outward and stay still. This gives you time to attach the tea bag to the arm and place the mug of hot water underneath. Finally the switch can be placed into “brew” mode. In this mode, the bag is lowered into the hot water and held for approximately five minutes. Each minute the bag is raised and lowered to stir the water around.

Once the cycle completes, the Nano plays a musical tune from the piezo speaker to remind you to drink your freshly made tea. All of the parameters including the music can be modified in the Nano’s source code. All of the components are housed in a small wooden box painted white. Check out the video below to see it in action. Continue reading “Automated Tea Maker” →