28 August, 2012

27 o'clock

In Japan, I was surprised to see Osaka FM802 Funky Music Station listing their times in 24h notation all the way up to around 2759... turns out in radio (even apparently in the rest of the world), the day changes at 4am, so the clock runs from 0400 to 2800-δ.

14 August, 2012

os x disk eject

Since 2006 I've been slightly frustrated by having to go to the desktop to eject removable media on my Mac laptop.

Finally I got round discovering the built-in diskutil command.

$ df -h
/dev/disk7s1   1.8Gi  1.8Gi   71Mi    97%    /Volumes/CANON_DC

$ diskutil unmountDisk /dev/disk7
Unmount of all volumes on disk7 was successful

Much nicer than sync... sync... pull.

11 August, 2012

undervoltage

It sounds like a common cause of problems sticking peripherals onto a Raspberry Pi come from unsufficient power supply.

They have a USB port for feeding power in, and I think that encourages people (including myself) to use any old USB compatible supply (even though they explicitly tell you to not do that in the docs...). I tried mine first feeding from my laptop and then from my mifi power supply.

That mifi supply seems to work for regular usage but when I start plugging things into USB it gets all wanky. So I measured the voltage with my trusty old multimeter - it seems to be down around 4.6v, (varying by about 0.1v depending on what I have wired in). That's well below the 4.75v minimum that apparently I should be seeing.

Off the the RS online shop to buy a grown up power supply then...