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Andy Clark's Blog

48 posts
I was in the Arduino forum the other day, in the Portenta section and I read something rather odd about a bit of MBed software. It's called, as I understand it... Serial crash dump.   I have been experimenting with Arduino Portenta and an Adafruit E-Ink display which uses SPI. It wasn't working at all so I wondered if it was that the SPI bus was configured quite as I expected. So I swapped in some alternative pins and was greeted by an unresponsive board that was flashing its red LED. Whic ...
Following on from my posts looking at the Portenta H7 Vision Shield I wanted to see if I could get the dual boot working with Micropython running on the M7 core and C running on the M4 core. So I posted in a bunch of forums and got some help from Ibrahim Abdelkader over on the OpenMV forums.   https://forums.openmv.io/t/portenta-micropython-on-m7-core-c-on-m4-core/6201   Ibrahim pointed me at some suitable code and advised me that I'd need to compile it from source but reminded me th ...
I've recently been experimenting with MicroPython on the Pi Pico. There are a few steps you need to get this setup.   Install the MicroPython Firmware Suitable editor Upload the code Setting the code to run at boot   Although it is designed for a younger audience, I found the "Getting Started with MicroPython" book to be a useful reference. I also used the pi-pico-python-sdk   Installing the firmware Installing the firmware is covered on the the https://www.raspberrypi.org/ ...
When looking at 2020, I have mixed feelings. I started January on a high note, I had just been published in Popular Science for my Dancemat project. I'd also been looking at power management in the TMC2300 Stepper Motor driver. And had successfully use UV curing resin for a simple project. I was also actively searching for a new job and had found a good company to work for, that lead to an interview and offer in February. However in March, just 2 days after I left my previous job the spec ...
Having moved house back in September I'm slowly getting the workshop into shape. I've bought some benches and given the first one a coat of "garage floor" paint. This should make for a hard wearing surface. I've also decided that the maker cabinet to the right of the first picture will be just electronics and related. Other tools will be placed into plastic boxes and placed onto the big shelving at the back of the workshop. There should also be some dedicated space for garden tools. One challeng ...
I've been experimenting with the Arduino MKR Zero board and wanted it to act as a USB keyboard. This board is based on the SAMD21 processor core which has a native USB wired to one of the sercom peripherals. But when I tried it out the keyboard was not sending data to the PC. I swapped to the simplest example I could find but still no luck. I also tried the https://github.com/NicoHood/HID library to see if that worked any better than the Arduino one but no luck.   Looking in device manage ...
After experimenting with the V2DIP1-48 from FTDI connecting over SPI, SPI Slave on an Arduino MKR Zero, I wasn't sure if the Arduino code or the FTDI firmware was the problem. After some more experiments I concluded that there was definitely something up with the firmware.   Reading one of the examples, I spotted the following gem: This sample has been designed for the V2Eval Board Rev 2.0 and later. V2Eval Boards have the version printed on the silk screen next to the V2EVAL label. The ...
I've a device which acts as a SPI Master and sends data over to my microcontroller which is acting as a slave. Simple, I thought, there'll be some stuff in the Arduino SPI library that will help with that. But no, that's just for the master case. When I googled it, I found many examples like this one https://gist.github.com/chrismeyersfsu/3317769 from Chris Meyers which uses the SPCR and SPDR registers and an ISR interupt to process the data. The problem is, that all three of these things are AV ...
I've recently been looking at machine learning techniques for analysing data, in particularly text classification and sentiment analysis. For this I'm using Tensor Flow Lite which can be run against edge devices such as microcontrollers. Thanks to Simone Salerno, I've got this running on an Arduino MKR Zero using his EloquentTinyML library.   But there are some challenges with processing text. To get the best results some processing is recommended. The raw text is filtered and cleansed, ...
At the end of the previous year, I'd been working on an Azure Sphere based project and that drew to a conclusion in January due to the immaturity of the SDK at the time. But the project was reimagined as the enchanted compass using an Arduino MKR1000 and 3D Printed shell.   So I then started on a UV Exposure badge based on the Pocket Beagle, this project was then adapted for a magazine article for Diyode magazine and a custom PCB and ATMega/Arduino board was made. In the process I learnt ...
I have just been sent a PanaVise Jr and a few other goodies thanks to Daniel from Element14.   From young age I've just soldered stuff on a solder mat, propped up as required, I did try a small plastic vice in the past but it was not really working so I went back to my old ways. Fairly recently I started using a simple crocodile "helping hands" and that got me thinking about a proper PCB Vice and how that might speed up soldering and make my task easier.   The PanaVise Jr is just one ...
My experiments with U-Center and the GPS module had shown that the direction indication was not very reliable. Following a link in Kevin Saye's post, I discovered a command that should tell the orientation. But my device did not seem to be generating that. http://aprs.gids.nl
mea/#hdt   Reading a bit further, I realised that the compass feature was provided by a  HMC5883 connected over I2C on a second connector. So I soldered a green wire onto the SCL connector and a blue wire to th ...
OptoSensor As David Murphy mentions, a stepper motor solution needs to know where the arrow is pointing when the device starts up. Looking in the spares box, I saw I had a Omron EE-SY310 reflective sensor from an old tachometer project, I used the phone camera to test the IR LED was working. This device has an open collector output so it will pull a floating signal to ground. There does not seem to be any configurable pull-ups on the Azure Sphere so I added my own pull up resistor between O a ...
From the Overview in Visual Studio, you can get the "Device Status", from there you can get the application status of the attached device. It's also possible to launch the Azure Sphere developer prompt from here and run the "azsphere dev show-attached" command. When I ran that it showed that my operating system was out of date which makes sense given the SDK update earlier in the week. OTA updates If you run the show ota commands you can see what version and details you are running.   ...
Updated SDK This week there was an update of the SDK for the Azure Sphere so I thought I'd download that and the other tools I was using. The SDK now has support for storage, real time clock, storage and external MCU flashing, although it looks like the documentation and examples need a bit of work still. https://azure.microsoft.com/en-us/blog/update-18-11-for-azure-sphere-in-public-preview/   One message in the update was that there was a updated network driver for running a VPN over U ...