I’m using the VL6180X ToF (Time-of-Flight) sensors successfully in different projects. The VL6180X is great, but only can measure distances up to 20 cm and in ‘extended mode’ up to 60 cm. For a project I need to go beyond that, so the logical choice is the VL53L0X which measures between 30 cm and 100 cm or up to 200 cm. For this project I’m using the VL53L0X breakout board from Adafruit, but similar products are available e.g. from Pololu.
The Teensy boards are great, but as they are they are not really useful for real development, as they lack proper SWD debugging. In “Modifying the Teensy 3.5 and 3.6 for ARM SWD Debugging” I have found a way to get SWD debugging working, at that time with Kinetis Design Studio and the Segger J-Link. This article is about how debug the Teensy with free MCUXpresso IDE and the $20 NXP LPC-Link2 debug probe:
In the area of IoT (Internet of Things), one obvious need is to have a way to send and receive data with an internet protocol. MQTT (or Message Queue Telemetry Transport) is exactly like that: a light-weight Machine-to-Machine communication protocol. With the MQTT protocol a microcontroller (or ‘client’) can send data and/or subscribe to data. For example to the Adafruit.IO:
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 🙂 :
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.
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:
In “openHAB RGB LED Light Cube with WS2812B and NXP Kinetis” I started experimenting Kinetis boards, a LED cube diffuser and Adafruit WS2812B NeoPixel LEDs. That worked well, but I was not to very happy about the visual effect. So here is my next version: I wanted to have control over each side of the cube. For this I have built a cube inside the cube with a 3D printed structure:
This is Part 1 of a Mini Series. Manya has challenged herself to use the Adafruit NeoPixels (WS2812B RBG LEDs) with the Freescale FRDM-K64F board and the Kinetis SDK (see “Let’s play with Freescale FRDM-K64F“). I did a while back that with the FRDM-KL25Z board (see “NeoShield: WS2812 RGB LED Shield with DMA and nRF24L01+“). I used Processor Expert in my project (without the Kinetis SDK), and with this setup it is very easy. However, Manya wanted to do this with the Kinetis SDK and without Processor Expert. No surprise to me, she has found out that this setup with the Kinetis SDK and without the usage of Processor Expert is much more challenging (see “Not done yet!!“). I promised to Manya to give her a helping hand, so here we go! 🙂
Adafruit 8×8 NeoPixel Shield with Freescale FRDM-K64F Board
When I showed my 60 NeoPixel LED clock prototype to my daughter and her girlfriend, and they both wanted to have one right away :-). Well, that clock was just a proof of concept, with lots of temporary wiring. So I decided this week-end to beautify it and to make it look nice and clean(er). There is nothing like a week-end project with adding a few more LEDs and features :-).