Trying to get those pixel perfect macro shots on a budget? Build your own DIY low cost ring of light with a NeoPixel Ring and Trinket, Adafruit tiny arduino micro controller. The color and brightness of the LEDs can be programmed to color or pattern!
PIR sensors allow you to sense motion, almost always used to detect whether a human has moved in or out of the sensors range. They are small, inexpensive, low-power, easy to use and don’t wear out. For that reason they are commonly found in appliances and gadgets used in homes or businesses. They are often referred to as PIR, “Passive Infrared”, “Pyroelectric”, or “IR motion” sensors.
Create a box that only opens when the right person looks at it!
Face recognition is an exciting field of computer vision with many possible applications to hardware and devices. Using embedded platforms like the Raspberry Pi and open source computer vision libraries like OpenCV, you can now add face recognition to your own maker projects! In this project I’ll show you how to build a treasure box which unlocks itself using face recognition running on a Raspberry Pi.
This project explores the Adafruit PiTFT touchscreen and the Raspberry Pi camera board to create a simple point-and-shoot digital camera. One can optionally use WiFi and Dropbox (a cloud file storage and synchronization service) to automatically transfer photos to another computer for editing.
A Spectrum Analyzer shows the loudness of different frequency bands (low, mid, high) in real-time, letting you visualize music. Using a RasPi, RGB LED Strip and some wire, make yourself a dynamic display and media player. This project is based on some great python xmas light code from the LightShowPi project, and advanced users can even configure it for song voting via SMS!
The project runs in Python, even including the audio processing. It’s just able to play and analyze mp3s in realtime as long as your Pi isn’t doing anything else.
PN532 NFC/RFID controller breakout board – v1.3: The PN532 is the most popular NFC chip, and is what is embedded in pretty much every phone or device that does NFC. It can pretty much do it all, such as read and write to tags and cards, communicate with phones (say for payment processing), and ‘act’ like a NFC tag. If you want to do any sort of embedded NFC work, this is the chip you’ll want to use! (read more)
In this guide, we are going to give a modern touch to gardening and connect some informations about your garden to the Internet. We are going to use a soil moisture & temperature sensor connected to an Arduino and a WiFi chip to automatically send measurements from your garden to the cloud.
We’ll use a service call Carriots to handle the data and display it nicely on a webpage. Then, an email or SMS alert can be send to you automatically if the moisture falls below a given threshold. The picture below represents the system when fully assembled and with the sensor buried into the soil next to a plant.
Don’t worry, you don’t actually need to have a garden or even plants (although we think plants are great to have) to use the content of this article: what you are going to learn can be used for any remote measurement projects. Let’s dive into the project!
Making on the go gets easier every year. With your hacking parts bundled with a computer, you travel to class, the makerspace, or a friend’s house and build your favorite circuits. Up to now, this probably meant carrying around a bulky laptop. But the weight and the value of your primary computing device probably makes that option unappealing (“if my Macbook or laptop were to break, I’d be sunk!”).
Fortunately you have some great alternatives today at very reasonable price points. Android tablets with modern versions of the Android operating system can be found below $200. In addition, there is a new crop of modern tablets powered by the Intel Bay Trail CPU and run full versions of Windows 8.1 (not the restricted Windows RT system). You can opt for the full Surface Pro system but that is nearly as bulky as an ultrabook. New 7″ and 8″ class tablets with high definition screens (“more pixels than retina”), make a much more portable alternative.
With a full Windows system, you have the gamut of developer tools at your fingertips. The Arduino IDE runs well and you can access code from the web, from the cloud, or locally.
With Android, you cannot directly install code from the Arduino project as Android is not a supported operating system. But there are programmers porting the Linux versions to Android.
The main method to communicate from tablet to microcontroller is the USB port. Tablets most often have microUSB ports conforming to the portable OTG (On the Go) specification which is great as they can act as slave ports for peripherals or as masters to control things. A simple OTG cable, available in the Adafruit shop, allows the tablet to communicate with outside devices. For an Arduino Uno, you can then use the regular (or 6 inch) A to B cable. Other boards may require mini or micro USB cables. The OTG cable provides a standard size A socket, making mating cables straightforward.
An appealing alternative to cables is Bluetooth. For Windows, we’ll cover programming an Arduino Uno wirelessly via the Adafruit Bluefruit EZ-Link board and shield.
These tablets are photographed with the Arduino Uno and LadyAda’s Bento Box, a portable “hack and pack” solution. Bento makes a great carry case for your projects and is about the same size as these new tablets.
Science, Technology, Engineering, (Art) and Math (STEM / STEAM) curriculum is gaining momentum in K-12 education. It’s exciting to see so many new makers and engineers learning how fun it is to make! I wanted to design a low cost robot that anyone could build if they have access to a 3D printer.
So… here’s an idea that might help – an autonomous micro rover based on Trinket.
This little USB port go-between is like a speed gauge for your USB devices. Instead of hauling out a multimeter and splicing cables, plug this in between for a quick reading on how much current is being drawn from the port. Great for seeing the charge rate of your phone or tablet, checking your battery chargers, or other USB powered projects.
Data is passed through transparently from end to end, so you can use it with any USB device at any speed. The power line has a 0.1 ohm current sense resistor an an INA169 high-side current sensor that is tracked by a little ATtiny85 chip. The microcontroller is programmed to read the current draw as well as the bus voltage and light up the strip of LEDs on the side.
The LED strip gives you a quick visual “power OK” and an indication of your power usage. But we also stream the data to a serial port so you can monitor, log and/or plot it on your computer!
The gauge comes as a mini kit with an assembled & tested PCB plus a separate USB jack and plug as shown above. The instructions on the following pages will show you how to assemble and use this handy gauge.
Many alarm projects are rather simplistic: a single sensor protects a single object or field of view. Such projects are good for learning or practicing simple circuit techniques. But eventually you may wish to have a more advanced / sophisticated alarm system. More like those used by commercial alarm companies. Actually the circuits needed to accomplish this are still fairly simple and can be built around the Adafruit Trinket mini microcontroller.
The Raspberry Pi does not have any analog inputs, but that does not mean that you can’t use some types of analog sensors. Using a couple of resistors and a capacitor, you can use a “step response” method to measure resistance. Which is just great if you are using a pot, photoresistor or thermistor.
…Open an editor (nano or IDLE) and paste in the following code. As with all the program examples in this book, you can also download the program from the Code section of the Raspberry Pi Cookbook website, where it is called pot_step.py….