Made by Mikal – Page 15

Gangscan 0.6 boards

Post author:mikal
Post published:May 20, 2019
Post category:Gang Scan

So I've been pottering away for a while working on getting the next version of the gang scan boards working. These ones are much nicer: thicker tracks for signals, better labelling, support for a lipo battery charge circuit, a prototype audio circuit, and some LEDs to indicate status. I had them fabbed at the same place as last time, although the service was much faster this time around. I haven't got as far as assembling a board yet -- I need to get some wire thin enough for the vias before I can do that. I'll let you know how I go though.

Trigs map

Post author:mikal
Post published:May 19, 2019
Post category:Tip

A while ago I had a map of all the trig points in the ACT and links to the posts I'd written during my visits. That had atrophied over time. I've just spent some time fixing it up again, and its now at https://www.madebymikal.com/trigs_map.html -- I hope its useful to someone else.

Trail run: Tuggeranong Stone Wall loop

Post author:mikal
Post published:May 18, 2019
Post category:Trail run

The Tuggeranong Stone wall is a 140 year old boundary between to former stations. Its also a nice downhill start to a trail run. This loop involves starting at the Hyperdome, following the wall down, and the continuing along to Pine Island before returning. Partially shaded, and with facilities at the Hyperdome and Pine Island. 6km, and 68m vertically. [kml: 20190427-1]

Trail run: Lake Tuggeranong to Kambah Pool (return)

Post author:mikal
Post published:May 18, 2019
Post category:Trail run

This wasn't the run I'd planned for this day, but here we are. This runs along the Centenary Trail between Kambah Pool and Lake Tuggeranong. Partially shaded, but also on the quite side of the ridge line where you can't tell that you're near the city. Don't take the tempting river ford, there is a bridge a little further downstream! 14.11km and 296 vertical ascent. Be careful of mountain bikers on this popular piece of single track. You're allowed to run here, but some cyclists don't leave much time to notice other track users. [kml: 20190511-1]

Trail run: Barnes and ridgeline

Post author:mikal
Post published:May 18, 2019
Post category:Trail run

A first attempt at running to Barnes and Brett trigs, this didn't work out quite as well as I'd expected (I ran out of time before I'd hit Brett trig). The area wasn't as steep as I'd expected, being mostly rolling grazing land with fire trails. Lots of gates and now facilities, but stunning views of southern Canberra from the ridgeline. 11.11km and 421m of vertical ascent. [kml: 20190502-1]

Trail run: Pine Island South to Point Hut with a Hill

Post author:mikal
Post published:May 18, 2019
Post category:Trail run

This one is probably a little bit less useful to others, as the loop includes a bit more of the suburb than is normal. That said, you could turn this into a suburb avoiding loop quite easily. A nice 11.88km run with a hill climb at the end. A total ascent of 119 metres. There isn't much shade along the run, but there is some in patches. There are bathrooms at Point Hut and Pine Island. Be careful of mountain bikers on this popular piece of single track. You're allowed to run here, but some cyclists don't leave much time to notice other track users. [kml: 20190220-1]

Trail running guide: Tuggeranong

Post author:mikal
Post published:May 18, 2019
Post category:Trail run Tuggeranong trail run

I've been running on trails more recently (I'm super bored with roads and bike paths), but running on trails makes load management harder -- often I'm looking for a run of approximately XX length with no more than YY vertical ascent. So I was thinking, maybe I should just write the runs that I do down so that over time I create a menu of options for when I need them. This page documents my Tuggeranong runs.

Trail run: Cooleman Ridge

Post author:mikal
Post published:May 18, 2019
Post category:Trail run

This run includes Cooleman and Arawang trig points. Not a lot of shade, but a pleasant run. 9.86km and 264m of vertical ascent. [kml: 20190425-1]

Ignition!

Post author:mikal
Post published:May 5, 2019
Post category:Book

Whilst the chemistry was sometimes over my head, this book is an engaging summary of the history of US liquid rocket fuels during the height of the cold war. Fun to read and interesting as well. I enjoyed it.

Using a MCP4921 or MCP4922 as a SPI DAC for Audio on Raspberry Pi

Post author:mikal
Post published:April 11, 2019
Post category:Gang Scan

I've been playing recently with using a MCP4921 as an audio DAC on a Raspberry Pi Zero W, although a MCP4922 would be equivalent (the '22 is a two channel DAC, the '21 is a single channel DAC). This post is my notes on where I got to before I decided that thing wasn't going to work out for me. My basic requirement was to be able to play sounds on a raspberry pi which already has two SPI buses in use. Thus, adding a SPI DAC seemed like a logical choice. The basic circuit looked like this: Driving this circuit looked like this (noting that this code was a prototype and isn't the best ever). The bit that took a while there was realising that the CS line needs to be toggled between 16 bit writes. Once that had been done (which meant moving to a different spidev call), things were on the up and up. This was the point I realised that I was at a dead end. I can't find a way to send the data to the DAC in a way which respects the timing of the audio file. Before I had to do small writes…