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 a quarterfinalist in The Hackaday Prize.
Graphics accelerators move operations to hardware, where they can be executed much faster. This is what allows your Raspberry Pi to display high definition video decently. [Andy]’s latest build is a 2D sprite engine, featuring hardware accelerated graphics on an FPGA.
In the simplest mode, the sprite engine just passes commands through to the LCD. This allows for basic control. The fun part sprite mode, which allows for sprites to be loaded onto the FPGA. At that point, you can show, hide, and move the sprite. By overlapping many sprites, you something like the demo shown above.
The FPGA is from Xilinx, and uses their Block RAM IP to store the state of the sprites. The actual sprite data is contained on a 128 Mb external flash chip, since they require significant space.
The game logic runs on a STM32 Cortex M4 microcontroller which communicates with the FPGA and orders the sprites around. The FPGA then deals with generating frames and sending them to the LCD screen, freeing up the microcontroller.
If you’re wondering about the LCD itself, it’s 3.2″, 640 x 360, and taken from a Ericsson U5 Vivaz cellphone. [Andy] has a detailed writeup on reverse engineering it. After the break, he gives us a video overview of the whole system.
Continue reading “Sprite Graphics Accelerator on an FPGA”
The Engine Control Unit is a vital part of every car made in the last 40 years or so, but unlike just about every other electronic device, open source solutions just don’t exist. [Andrey] is trying to change that with rusEfi, a project that hopes to bring together hardware, software, and engines in one easy to use package. He’s even designed Frankenstein, a full ECU ‘shield’ for the STM32F4 Discovery dev board.
This isn’t the first time we’ve seen [Andrey]’s adventures in building an ECU. An earlier board was also powered by the STM32F4 Discovery, and he actually drove his 96 Ford Aspire around using this homebrew ECU. It was only firing on two cylinders, but that was only a loose solder connection.
Of course building an ECU from scratch is worthless without the proper firmware that balances and engine’s fuel economy and performance. This sort of testing must be done empirically and [Andrey] has a Kickstarter going for the development of this firmware and some dyno time. No rewards, but it’s worth chipping in a buck or two. I did.
Continue reading “Frankenstein, The Open Source Engine Control Unit”
[Linas] reverse engineered an AMOLED HTC 800×480 screen and interfaced it with an STM32 micro-controller, along with some other components, to make a gorgeously over engineered reflow oven.
Under the hood there is a PSoC5LP PID controller to control the 800W IR heating coil and two K-type thermocouples for sensing.
The real beauty is in the relatively small STM32 chip powering the HTC AMOLED screen. The AMOLED screen is high contrast and has a wide viewing angle, giving it a clear crisp view from all front facing viewpoints. Though pushing the limits of what the STM32F429i can do, [Linas] managed to make a very nice “home-grown” user interface, complete with user configurable settings and current temperature graphs.
The user interface looks very responsive and using some clever programming, [Linas] was able to make use of the potential of the screen to provide beautiful plots and interface widgets.
[Linas] goes into quite a bit of detail about the programming involved with rendering to the screen, so be sure to check out the video after the jump.
Continue reading “Smart Reflow Oven is Over-Engineered”
The STM32 line of microcontrollers – usually seen in the form of an ST Discovery dev board – are amazingly powerful and very popular micros seen in projects with some very hefty processing and memory requirements. Now, ST has released a great way to try out the STM32 line with the Nucleo board.
There are two really great features about these new Nucleo boards. First, they’re mbed compatable, making them a great way to get started in the ARM development world. Secondly, they have Arduino pin headers right on the board, giving you access to all your shields right out of the box.
Right now, there are four varieties of the Nucleo board based on the STM32F030, -F103, -F152, and -F401 microcontrollers. The STM32F401 is the high-powered variant, An ARM Cortex-M4 microcontroller running at 84 MHz, 512kB of Flash, and enough I/O for just about any project.
If you’d like to get your hands on one of the STM32 Nucleo boards, you can order a voucher to pick one up at Embedded World in Germany next week. Otherwise, you’re stuck ordering from Mouser or Farnell. Bonus: the high-end F401-based board is only $10 USD.
While we can’t condone the actual use of this device, [Husam]’s portable WiFi jammer is actually pretty cool. It uses a Raspberry Pi and an Aircrack-ng compatible dongle to spam the airwaves with deauth packets. The entire device is packaged in a neat box with an Arduino-controlled LCD and RGB LEDs. Check out an imgur gallery here.
You can pick up a wireless phone charger real cheap from any of the usual internet outlets, but try finding one that’s also a phone stand. [Malcolm] created his own. He used a Qi charger from DealExtreme and attached it to a 3D printed phone stand.
A while back, [John] noticed an old tube radio in an antique store. No, he didn’t replace the guts with a Raspberry Pi and an SD card full of MP3s. He just brought it back to working condition. After fixing the wiring (no ground cord on these old things), repairing the speaker cone, putting some new twine on the tuner and replacing the caps, [John] has himself a new old radio. Here’s a video of the complete refurbishment.
Here’s a Sega Master System (pretty much a Game Gear) running on an STM32 dev board. Also included are some ROMs for some classic games – Sonic the Hedgehog, Castle of Illusion, and The Lion King. If you have this STM Discovery board you can grab the emulator right here.
[Spencer] wanted a longer battery life in his iPhone, so he did what any engineering student would do: he put another battery in parallel.
Breadboarding something with an AVR or MAX232? Print out some of these stickers and make sure you get the pinouts right. Thanks, [Marius].
Umm yeah… this is more like it. The STM32F4Stamp is a project which [Frank Zhao] put together to make his ARM prototyping process more like is was back when everything came in a DIP format. As you can see, it’s just narrow enough to leave one row open on the breadboard for jumper wires.
Don’t get us wrong, we do really like STM’s own Discovery Boards for the hardware they deliver at a very low price. But the dual-row pin headers on the larger versions (all except the F0 variant) make it tricky to connect your peripherals. This is pushed to the point that a large percentage of hacks we’ve seen with the Discovery boards are actually just to make connecting external hardware easier.
You may be thinking that there’s a lot missing from this board, but we disagree. Obviously there’s still a USB port which can be used to power the board via a 3.3V regulator. But since the STM32 chips have a built-in bootloader the USB connection can also be used to flash firmware to the processor. Nice! It’s open hardware if you want roll your own. For your convenience we’ve embedded the schematic after the break, along with [Frank’s] demo video.
Continue reading “Breadboard Friendly ARM Board Based on STM32F4”