I’m trying to embed a Jupyter notebook page as a blog post. I saved it as html, and copied an pasted that html below. I don’t think that’s the best way to do it.
We are exploring the Adafruit Metro M4 Express
[Read More...]EBD-USB+ Electronic Load – Testing Power Supplies and Batteries
I watched a video from Andreas Speiss reviewing electronic loads, and identifying one in particular called EBD-USB+ from zketech.com and purchased through Amazon or Banggood or wherever. The software is a little hard to find, but it’s available through this link. It comes as a .rar file, which you might need to unpack with 7-zip or Winzip. You will also need the driver.
[Read More...]Thoughts on serial communications
Maybe these issues have been solved in the past. I don’t think there is necessarily a very good solution, though.
The problem is that serial communications is imperfect. Characters get messed up in transit between two devices. When they do, that in turn messes up carefully thought out protocols, like “Capture characters in a buffer until you see the linend; then process the buffer as a single message.”
[Read More...]Teensy, touch sensing, and ESP8266 – via MQTT and Raspberry Pi
Whee!
I have a demo/development setup on a small breadboard which powers an ESP-01 ( the small, cheap, 8-pin breakout board for an ESP8266 chip ). In addition to being a programming board, it has 3v3 voltage regulation, a pot, a temperature sensor, a simple LED, and a WS2812 3-color LED. I have the installed ESP8266 running a program to subscribe to an MQTT broker and light the LEDs according to publications on a certain topic.
[Read More...]Securing a Raspberry Pi IoT Gateway
I believe that the UMass IT policy forbids “rogue” WiFi gateways in order to prevent anonymous Internet access, so that nefarious actors can be identified.
I needed to create an IoT server for my lab, M5, and it needed to be accessible via WiFi. It also needed to have Internet access so that I could keep its Linux firmware up to date.
[Read More...]Calculating the Axis of Nutation of my Solar Tracker
Following on the cluster analysis of the last post, I pairwise crossed (as in cross-multiply) the resulting cluster centers, and got three reasonably-close vectors after normalization. These were:
0 x 1: (-0.36, 0.93, -0.10) 0 x 2: (-0.23, 0.97, -0.06) 1 x 2: (-0.20, 0.97, -0.14)
While satisfyingly close, I wanted to do better.
[Read More...]Instrumenting and Analyzing My Solar Tracker
I’m an instrumentation and data collection geek. I love the challenge of developing ways to monitor the systems of my house and making sure they’re working properly. I’ve had a couple bad experiences where systems failed and not knowing it soon enough caused problems.
[Read More...]Quaternions are fun!
Once upon a time, I was a math major. I shunned engineering as not pure enough — I wanted to be a scientist. And I didn’t see that most of the really good mathematics is developed in support of other sciences, particularly physics, and engineering. Fourier analysis. Eigenfunctions. Complex numbers. And linear algebra.
[Read More...]Documentation!
Whew. I just read LadyAda’s post about using Doxygen to document a project, and setting GitHub up to not only host the files, but also to serve the documentation as html. I managed to do most of it!
[Read More...]Doxygen seems pretty cool
I’ve just (belatedly) added Doxygen commentary to the firmware I’ve written for the OpenEffects Project hardware. It was half a day’s work, but it was reasonably painless to install Doxygen and Graphviz dot, even starting from scratch as I was.
[Read More...]