It is easy to imagine how early man started using rocks and then eventually developed better and better tools until they created the hammer. Some simple tools took a little longer to invent. The spirit level, for example, didn’t exist until sometime in the last half of the 1600’s.
The idea is simple. A clear tube holds a liquid and a bubble. When the bubble is in the center of the tube, the device is level in the direction of the tube. [Mark Williams] has a slightly more involved approach. He took an internal measurement unit (IMU) and a Raspberry Pi to create a modern take on the spirit level.
Eddie is a surprisingly capable tiny balancing robot based around the Intel Edison from which it takes its name.
Eddie’s frame is 3D printed and comes in camera and top hat editions. The camera edition provides space for a webcam to be mounted, since the Edison has enough go power to do basic vision. The top hat edition just lets you 3D print a tiny top hat for the robot.
The electronics are based around the Edison board and Sparkfun’s set of, “Blocks” designed for it. This project needs the battery block, the H-Bridge block, the GPIO block, and the USB block along with a 9DOF block for balancing. It’s, somewhat unfortunately, not a cheap robot. The motors are Pololu all-metal gearmotors with hall-effect sensors acting as encoders.
We’re really impressed with [diabetemonster]’s design and documentation on the robot. Full source code is provided along with a very nice build guide to get the platform going fast.
There are a few videos of it in action, available after the break. They show it handling situation such as a load being placed on the robot and slopes as well as bonus features like dancing and remote control.
[Alvaro Ferrán Cifuentes] has built the coolest motion capture suit that we’ve seen outside of Hollywood. It’s based on tying a bunch of inertial measurement units (IMUs) to his body, sending the data to a computer, and doing some reasonably serious math. It’s nothing short of amazing, and entirely doable on a DIY budget. Check out the video below the break, and be amazed.
Cellphones all use IMUs to provide such useful functions as tap detection and screen rotation information. This means that they’ve become cheap. The ability to measure nine degrees of freedom on a tiny chip, for chicken scratch, pretty much made this development inevitable, as we suggested back in 2013 after seeing a one-armed proof-of-concept.
But [Alvaro] has gone above and beyond. Everything is open source and documented on his GitHun. An Arduino reads the sensor boards (over multiplexed I2C lines) that are strapped to his limbs, and send the data over Bluetooth to his computer. There, a Python script takes over and passes the data off to Blender which renders a 3D model to match, in real time.
All of this means that you could replicate this incredible project at home right now, on the cheap. We have no idea where this is heading, but it’s going to be cool.
The reason we’re playing with quadcopters, flight controllers, motion controlled toys, and hundreds of other doodads is the MEMS revolution. A lot is possible with tiny accelerometers and gyroscopes, and this is looking like the smallest IMU yet. It’s an 18mm diameter IMU, with RF networking, C/C++ libraries, and a 48MHz ARM microcontroller – perfect for the smallest, most capable quadcopter we’ve ever seen.
The build started off as an extension of the IMUduino, an extremely small rectangular board that’s based on the ATMega32u4. While the IMUduino would be great for tracking position and orientation over Bluetooth, it’s still 4cm small. The Femtoduino cuts this down to an 18mm circle, just about the right size to stuff in a model rocket or plane.
Right now, femtoIO is running a very reasonable Kickstarter for the beta editions of these boards with a $500 goal. The boards themselves are a little pricey, but that’s what you get with 9-DOF IMUs and altimeter/temperature sensors.
This particular guide goes through the setup of SDL to control the video output to a small screen. Then, a function is created to rotate the images based on input from the IMU so that the vehicle position can be shown graphically on the screen. Now, when your truck is about to roll over on a hill, you’ll get advance warning!
Of course, this whole project is predicated on installing the IMU and getting it up and running on the Raspberry Pi in the first place. [Mark] has you covered on a guide for setting that up as well. This delves into setting up the IMU over I2C to get it talking to the Raspberry Pi, and then converting the raw data from the IMU into data that is more usable. Be sure to check out [Mark]’s page for all of the code and details!
The best projects have a great story behind them, and the Apollo from Carbon Origins is no exception. A few years ago, the people at Carbon Origins were in school, working on a high power rocketry project.
Rocketry, of course, requires a ton of sensors in a very small and light package. The team built the precursor to Apollo, a board with a 9-axis IMU, GPS, temperature, pressure, humidity, light (UV and IR) sensors, WiFi, Bluetooth, SD card logging, a microphone, an OLED, and a trackball. This board understandably turned out to be really cool, and now it’s become the main focus of Carbon Origins.
There are more than a few ways to put together an ARM board with a bunch of sensors, and the Apollo is extremely well designed; all the LEDs are on PWM pins, as they should be, and there was a significant amount of time spent with thermal design. See that plated edge on the board? That’s for keeping the sensors cool.
The Apollo will eventually make its way to one of the crowdfunding sites, but we have no idea when that will happen. Carbon Origins is presenting at CES at the beginning of the year, so it’ll probably hit the Internet sometime around the beginning of next year. The retail price is expected to be somewhere around $200 – a little expensive, but not for what you’re getting.
There are a ton of apps out there for taking notes and recording ideas, but sometimes the humble pen is best. However, if you have the tendency to lose, crumple, or spill caffeinated beverages on your pen and paper notes, having a digital copy is quite nice.
The NoteOn Smartpen by [Nick] aims to digitize your writing on the fly while behaving like a normal pen. It does this by using the ST LSM9DS0TR: a 9-axis inertial measurement unit (IMU). These inertial measurements are processed by a STM32 Cortex M4F processor and stored on the internal flash memory.
To retrieve your notes, the Nordic nRF8001 Bluetooth Low Energy radio pairs the MCU with a phone or computer. The USB port is only used to charge the device, and the user interface is a single button and LED.
The major hardware challenge of this device is packaging it in something as small as a pen. Impressively, the board is a cheap 2 layer PCB from OSHPark. The assembled device has a 10 mm diameter, which is similar to that of ‘dumb’ pens.
The NoteOn doesn’t require special paper, and relies only on inertial measurements to reconstruct writing. With the hardware working, [Nick] is now tackling the firmware that will make the device usable.
The project featured in this post is 
