One of the biggest road blocks (beside of closed source) using the BLE (Bluetooth Low Energy) stack from NXP is that it requires expensive tools to compile and build the stack. The good news is that I have now the NXP BLE stack for the Mikroelektronika Hexiwear ported to Eclipse and GNU gcc build tools for ARM 🙂
Monthly Archives: December 2016
Obhäg
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Using Python, Gatttool and Bluetooth Low Energy with Hexiwear
Now I can use the data on the Hexiwear over BLE with the gatttool (see “Tutorial: Hexiwear Bluetooth Low Energy Packet Sniffing with Wireshark” and “Tutorial: BLE Pairing the Raspberry Pi 3 Model B with Hexiwear“). This article is taking things a step further and uses a Python script on Linux to access the sensor data on the BLE device:
DIY IKEA Wireless Qi Charging for the Hexiwear
The Achilles Heel of the Mikroelektronika Hexiwear is its charging: the charging and USB connector are only designed for a limited number of plug-unplug cycles, and it does not have a wireless charging capability like the Apple iWatch. Until now! I have built a DIY wireless charging system for the Hexiwear 🙂 :
VNC Server on Raspberry Pi with Autostart
The Raspberry Pi is a versatile mini computer: as such I can use it with USB keyboard, mouse and HDMI LCD monitor. But having multiple keyboards and mouse on my desktop is not my thing: somehow I always grab the wrong one. So what I prefer is to run the Raspberry with VNC (Virtual Network Computing). That way I have the Linux GUI as a window on my normal desktop, and no messing up with keyboards and mouse 🙂 :
Hexiwear with Raspberry Pi and OpenHAB Home Automation
This is yet another milestone on my journey to combine the Hexiwear with the Raspberry Pi: now I can send take over control of the Hexiwear with openHAB running on the Raspberry Pi:
Tutorial: Hexiwear Bluetooth Low Energy Packet Sniffing with Wireshark
For a university reasearch project I try to pair the Raspberry Pi 3 with a Mikroelektronika Hexiwear using BLE (Bluetooth Low Energy). Most of things worked after a lot of trial and error, but at a certain point I was stuck trying to write to send data from the Raspy to the BLE device.The Hexiwear BLE protocol description is very thin, so I ended up using a BLE sniffer to reverse engineer the protocol with Wireshark.
Disabling EzPort on NXP Kinetis to Solve Power-On Issues
I’m using the NXP FRDM-K64F board in several projects: it is reasonably prices, has USB, Ethernet, micro SD card socket and connectors for Bluetooth classic and Nordic Semiconductor nRF24L01+ 2.4 GHz transceiver:
But one issue I have faced several times is that the board works fine while debugging and connected and powered by a host machine, but does not startup sometimes if powered by a battery or started without a debugger attached. I have found that the EzPort on the microcontroller is causing startup issues.
Tutorial: BLE Pairing the Raspberry Pi 3 Model B with Hexiwear
The Hexiwear (see “Hexiwear: Teardown of the Hackable ‘Do-Anything’ Device“) is a small and portable sensor node with built-in BLE (Bluetooth Low Energy) transceiver. In a research project we try to use multiple Hexiwear in a classroom environment and to collect sensor data on a Raspberry Pi. The Raspberry Pi 3 Model B running Linux has an on-board BLE transceiver too, so why not binding them (wirelessly) together?
Well, things seemed easy at the beginning, and as always, there are many things to learn on a journey like this…
Low Power LCD: Adafruit Breakout Board with Sharp Memory Display
Many projects benefit from a small display as a user interface. For very low power applications this is usually a no-go as the display needs too much energy. I have used e-paper displays from Kent: while these e-paper displays do not need any power to keep the image, changing the display content is not for free, plus is very slow (around 1 second needed to update the display). So I was looking for something low power and fast for a long time, until Christian (thanks!) pointed me to a display from Sharp: both very low power and fast:
Frosted Japanese Umbrella Pine
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Cold and humid air are forming beautiful sculptures these days. The image shows the leaves of a Japanese Umbrella-Pine (Sciadopitys):
Happy Frosting 🙂
McuOnEclipse Components: 12-Dec-2016 Release
Time is passing by so fast, and the year end is approache fast! I’m pleased to announce that a new release of the McuOnEclipse components is available in SourceForge:
- Percepio Trace V3.1 for FreeRTOS which includes both Segger RTT continuous streaming and snapshot tracing in a single API
- Generation of sources and drivers so they can be used without Processor Expert using McuLibConfig, removal of dependency to NXP Kinetis SDK: components use a generic API approach to have them working with other SDKs.
- New contributed ExceptionsHandler component
- Callback Setter and Getter in USB CDC stack for simpler option handling
- GenericTimeDate with flexible RTC support and added Unix Timestamp functions
- LongKey events in Key component
- FreeRTOS with optimized task selection on Cortex-M4/M7
- Many smaller bug fixes and enhancements
Qi Wireless Charging Transmitter with 3D Printed Enclosure
For my Hexiwear university research project I’m exploring wireless charing options. I have built a DIY Qi charging station and created a 3D printed enclosure for it:
Red Sunday Morning
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Flashing and Restoring the Hexiwear Firmware
The Hexiwear device is a great and versatile device with two microcontrollers on it. Developing firmware on a Hexiwear means changing what was originally on it. And sometimes it happens that I’m not sure if the changes are for good. Or that I accidentally destroyed the firmware on the NXP Kinetis KW40 BLE microcontroller :-(. So I had to find a way to restore the original firmware, and this is what this post is about.
Sunrise with Föhn
A sunrise which reminds me that nature creates the most beautiful pictures:
Scene created by the Föhn wind moving clouds over the Swiss Alps, and the sun rising behind the Mythen mountains.
Happy Sunrising 🙂
Prototype of tiny Hexiwear Docking Station
For a research project we are using Hexiwear to measure the effectiveness of teaching and learning. The Hexiwear is used as a networking sensor device in that project. For that project we needed a docking station with wireless capabilities:
Where is the Sun?
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Mother nature offered an interesting puzzle this morning: a sunrise with beautiful light sculptures. But where is the sun?
Tutorial: STMicroelectronics VL6180X Time-of-Flight LIDAR Sensor
For many of my applications I need to measure a distance. I have used ultrasonic sensors, but there view angle (beam) is not able to detect smaller objects, it very much depends on the object surface and angle, it is slow and not very precise. I have used infrared sensors, but here again it depends on the infrared reflection of the object in range, it depends the amount of reflected light is not really telling much about the distance, and yet IR reflection is subject of material and object targeted.
But there is yet another sensor type to consider: ToF! ToF (or Time-of-Flight) sensors have a built-in LIDAR: The sensor is sending out light pulses and measures how much time it takes for the light to come back. Similar to ultrasonic sensors (see “Tutorial: Ultrasonic Ranging with the Freedom Board“), but instead of ultrasonic it uses an infrared laser light. Or think about a radar system using an infrared laser light.