I've had some time to work on my Teensy Load project recently. I got the boards a couple of weeks ago, assembled one, found that it didn't really work, and tracked that problem down to a wrong-way-round diode (due to a weird symbol definition I'd used from the wrong KiCad library).

And yesterday I did some end-to-end testing using the tl-meter software that I wrote. And it (partially) worked!

I made a video of the testing, mostly to share on the Contexual Electronics forum. It's a bit slapdash, but it does show how the tl-meter software works, and shows how it ought to be practical to use the Teensy Load as a real tool.

There are a couple of things to bear in mind if you watch the video:

  1. I had done no testing of the tl-meter with the real hardware running the real firmware, so it's all a bit wobbly. And I discovered a couple of bugs, so not everything I wanted to try worked first time. (I developed the tl-meter software using some simulation firmware I wrote to run on the Teensy, so that I could work on the software more conveniently, without needing to set up test devices and so on.)

  2. The sound quality in the first part of the video is terrible. There was a huge rainstorm, I had the door open, and didn't really pay attention to just how loud it was. (I also didn't pay attention to the rain coming in through the door into the other room of the shed, so I had to mop up a little flood when I was done!)

There's some work to be done on calibration and fixing the bugs I found (which are probably software or firmware issues, rather than hardware). I also want to write some more little utilities to measure V/I curves and discharge curves, to complement the "meter" software in the video.