arduino

2931 Articles

PIDDYBOT – A Self Balancing Teaching Tool

January 17, 2014 by 9 Comments

We’re sure that most Hackaday readers are already familiar with the inverted pendulum system, which basically consists of a pendulum having its center of mass above its pivot point. Most applications (like the one we are going to describe) limit the pendulum to 1 degree of freedom by affixing the pole (or circuit board here) to an axis of rotation. The overall system is therefore inherently unstable and must be actively balanced in order to remain upright.

[Sean] created the piddybot, a tiny balancing robot aimed to teach the basics of PID control by trying to get the robot to stand still. More interestingly, the Proportional / Integral / Derivative values can directly be adjusted using the three on-board potentiometers. This will allow users to get the feel of each parameter’s impact on the robot behavior. The piddybot is based around the Arduino nano, a custom PCB, 2x 26:1 geared motors, one 1A dual motor driver board, a six degrees of freedom Inertial Measurement Unit, 2 batteries and finally a 3D printed body. You can check out a video of the robot in action after the break.

This project stems from a non-PID self balancer which [Sean] hacked together in September.

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Lux: A 100% Open Source Camera

January 15, 2014 by 29 Comments

luxCamera

[Kevin Kadooka] recently finished his open source camera. The Lux Camera is 100% open source. Lux uses no parts from other cameras – not even a lens! To date we’ve only seen this with achieved with pinhole cameras. [Kevin] isn’t new to camera hacking. He was the man behind the Duo camera, which had a successful Kickstarter campaign in February of 2013. Duo is a DIY camera, but it still required lenses from Mamiya-Sekor, and a shutter from Seiko. Lux is a different animal. It has a manual focus 65mm f/5.6 Single Element lens. The shutter is [Kevin’s] own solenoid based leaf shutter design. Just as in the original shutter, an Arduino controls shutter operation and timing.

The main camera body and many of its parts are 3D printed. [Kevin] got some very nice quality parts from Shapeways 3D printing service. We have to say that some of the assemblies look a bit complex for desktop printers. However since everything is open source, anyone willing to put the time in could adapt them for the average RepRap or Ultimaker. [Kevin] has posted detailed build photos, as well as some photos taken with the Lux on his flickr stream. The pictures have  a decidedly holga-esque look to them, due in part to the single element lens. Even with this limitation, we love the idea of having a brownie style camera built completely from scratch.

Android+Arduino – Face Following RC Car

January 15, 2014 by 25 Comments

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To some of us, hacking an RC Car to simply follow a black line or avoid obstacles is too easy, and we’re sure [Shazin] would agree with that, since he created an RC Car that follows your face!

The first step to this project was to take control of the RC Car, but instead of hijacking the transmitter, [Shazin] decided to control the car directly. This isn’t any high-end RC Car though, so forget about PWM control. Instead, a single IC (RX-2) was found to handle both the RF Receiver and H-Bridges. After a bit of probing, the 4 control lines (forward/back and left/right) were identified and connected to an Arduino.

[Shazin] paired the Arduino with a USB Host Shield and connected it up with his Android phone through the ADB (Android Debug Bridge). He then made some modifications to the OpenCV Android Face Detection app to send commands to the Arduino based on ‘where’ the Face is detected; if the face is in the right half of the screen, turn right, if not, turn left and go forward.

This is a really interesting project with a lot of potential; we’re just hoping [Shazin] doesn’t have any evil plans for this device like strapping it to a Tank Drone that locks on to targets!

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Your Mouse Is A Terrible Webcam

January 14, 2014 by 48 Comments

camera

It should come as no surprise your optical mouse contains a very tiny, very low resolution camera. [Franci] decided to take apart one of his old mice and turn that tiny optical sensor into a webcam.

Inside [Franci]’s Logitech RX 250 is an ADNS-5020 optical sensor. This three wire SPI device stuffed into an 8-pin package is a 15×15 pixel grayscale image sensor. [Franci] started this project by bringing out the Arduino and Ethernet shield. After soldering a pull-up resistor to the image sensor’s reset pin, connecting the rest of the circuit was as simple as soldering a few wires to the Arduino.

The Arduino sketch sends the image data for each pixel to a computer over a serial connection. A bit of javascript and a touch of HTML takes this pixel data and turns it into a webpage with a live view of whatever is directly under [Franci]’s mouse.

Video of the mousewebcam in action below.

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I Am The Midnight Message Board What Messages At Midnight

January 11, 2014 by 15 Comments

Photoluminescent stars on your bedroom wall or ceiling are pretty cool, though the stationary shapes can become boring. [Adi] felt this way, too. While doodling with a bright white light on some glow in the dark vinyl, it occurred to him that this could make for an interesting display. He set about making GLO, the midnight message board and RSS display.

[Adi]’s light writer uses 12 UV LEDs on a linear axis powered by a stepper motor to write RSS headlines, Twitter trends, or custom text on his wall. He finds the slow fade of the text very soothing to fall asleep by, and it’s easy to see why. The LED array imprints a section of a character consisting of a 6×5 bit pattern. The 12 LEDs are split into two groups, so it can write two lines at 45-50 characters each. [Adi] designed his own pixel font for this project, and advises that only upper case letter forms be used.

[Adi]’s write-up is quite admirable and comprehensive. In the circuit build section, he advises that the LEDs must be very close to the vinyl for optimum results, but that they should protrude farther than the shift registers so the chips don’t rub the vinyl. Of course you could opt for more intense light sources, like laser. See it in action after the break.

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Arduino Ball Throwing Game

January 9, 2014 by 8 Comments

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Building your own gaming platform is pretty cool on its own, but when the game actually looks like fun to play, well that’s on a different level of cool. [Zippy314] designed an Arduino based game platform as a Christmas present to his son called the Das Blinken Bonken!

Like all highly addicting games, the gameplay is simple; the player throws a ball at the target board while aiming to hit a specific ‘pad’. As shown in the video after the break, there are many game possibilities with this platform, like trying to hit the illuminated target each time, or just trying to hit all of the pads on the board as fast as possible.

A pad is registered as a ‘hit’ with the help of home-made pressure sensors, which are each constructed in a ‘sandwich’ of pressure-sensitive conductive sheets. This is the same material used in these LED Sneakers. Since the resistance through the sheet lowers as pressure is applied, a simple voltage divider circuit is used to feed the analog inputs on the Arduino, thus making it very easy to detect a ‘hit’. An I2C 4-Digit 7 Segment display keeps score and displays the game title, while a strip of addressable RGB LEDs give player feedback and other vital gameplay information.

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Controlling Cheap, Awesome Christmas Lights

January 7, 2014 by 13 Comments

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[James] was wandering around Walgreens after Christmas and found something very interesting – RGB LED Christmas lights that were individually addressable. At $6.50 for a strand of 15 lights, he just had to buy a few and figure out the control protocol. After all, who can turn down a big, cheap, controllable RGB LED strip?

The packaging for these lights – apparently manufactured by BriteStar – includes a ‘try me’ button that cycles through different light patterns. This button is what initially tipped [James] off to the fact the lights on this strand could be individually controllable. Opening up one of the lights, he found exactly what he wanted: an epoxy blob, two wires for power, and three wires for the signaling.

After checking out this light with a scope and logic analyzer, [James] realized there was a very, very simple protocol going on. Essentially, the entire string functioned as a gigantic shift register, taking the values for one light and pushing it down the string. In looking at the protocol, [James] also discovered] these lights support 16 levels of brightness. Yep, RGB LED Christmas Lights with PWM for under $7. Can’t beat that.

[James] wrote an Arduino library to control these strings and put it up on Github. While your local Walgreens has probably already hidden these lights away in the back of the store, it might be worth asking around to see if they have any left.