THP Semifinalist: NoteOn Smartpen

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.

SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.

THP Quarterfinalist: WALLTECH Smartwatch

While there is lots of hype about a big company launching a new wearable product, we’re more interested in [Walltech]’s open source OLED Smartwatch. This entry into The Hackaday Prize merges a collection of sensors and an OLED screen into a wearable device that talks to your smartphone over Bluetooth Low Energy.

The device is based on the IMUduino BTLE development board. This tiny Arduino clone packs an inertial measurement unit (IMU), a Nordic nRF8001 Bluetooth radio, and an ATMEGA32u4 microcontroller.

The 1.5″ OLED display comes from [miker] who makes an OLED module based on the SSD1351. A STP200M 3D pedometer provides activity monitoring in a tiny package.

On the hardware side, packaging all these components into something that will fit on your wrist is quite difficult. The prototype hardware is built from mostly off the shelf components, but still manages to be watch sized.

At this point, it looks like the code is the main challenge remaining. There’s a lot of functionality that could be implemented, and [Walltech] even mentions that it’s designed to be very customizable. It even supports Android; the Apple Watch can’t do that.


SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.