Archive for October 2014

Living roof for the shed: Which plants are still alive?

Most of them, it seems. Currently, nineteen out of twenty-one haven’t kicked the bucket.

Here’s what the roof looked like as planted, back in May.

And today:

Currently exploding are the carex secta, virgata, and fagillifera, at the top of the roof in the driest and windiest part. Down at the bottom of the slope, the pratia angulata/panekenake seems very happy. Somewhere in the middle is the leptinella, coprosma prostrata and acerosa, doing quite nicely, although the acerosa is pretty shaded by the trees to the north. The ferns in the darkest and wettest far corner are not dead yet. One of the muehlenbeckia complexa/puhuehue died straight away, the other is hanging in there, despite being in similar conditions. One of the hebe albicans got heavily shaded by a branch before I cut that back and looks like toast, the other is fine.

This suggests to me that the tussock will survive on the house roof, so I think we’ll plant some next winter. It’ll be good to see it standing proud over the low succulents and seddums. The only other tall stuff we have up there is hebe stricta, which I like, but grows everywhere and gets so big (above head height) that it’ll fall over in the thin soil on the house roof.

Mitochondrion Mark 5.0: First light

Yeah, this is going to be bright.

That’s the test power board, the test centre board, and the test strip. The power board holds four 16340 Li-Ion cells and a 5 Volt, 4 Amp converter (and some other gubbins). There’ll be four of them, one for each strip. The centre board holds the Teensy, motion sensor, FRAM, and level shifter (and a bunch of other gubbins). The test strip is 144 Neopixel LEDs. There’ll be 800 of them.

Testing reveals a bunch of issues to fix, but at least I’m at the stage of making light.

Mitochondrion Mark 5.0.1 progress: almost enough LEDs

The answer to the question “how many LEDs?” is always “moar!”. However, I think this counts as “almost enough”:

And you’ll note from the change in version number that the Mark 5.0 power design didn’t work out. The Mark 5.0.1 power design is underway. In short, while I could fit 18.2 mm diameter cells into a 19.6 mm space which also holds circuit boards and wiring, “could” is not the same as “should”. Hence the delicate trade-off of diameter, length, weight, energy, power, charging, balancing, and not catching fire means that 16340 cells are looking better than 18650s. This will result in downgrading the peak power output from “portable apocalypse” to “merely seizure inducing”, but you can’t have everything.*

* – Well, to be precise, you can have everything, but a large fraction of everything is planned for release in future versions.