Extending the Life of SD Card in Linux

Around the time I was looking at RPi power save, I was also checking into how to mitigate the effects of regular writes to the cheap SD card.  (Well, not so cheap, since I buy Samsung NAND.)  One link I found had references to several other sites.  The answer on the StackExchange page was pretty useful.

Amusingly enough, I left the HomeGenie event stream enabled for debug, which was generating output every 30 seconds...for at least a year.  I'd imagine the card is pretty well worn by now.

Updated PiFM

One of the guys on Slack #radio at work tried PiFM on his RPi2 and found that it didn't work.  Apparently the project's been abandoned.  He found an updated project, rpitx, that does work.  His interest was using it as a foxhunt transmitter, which is also pretty cool.

OBD-II

These links have been open in my browser for months.  Time to dump them!

ELM327 support in Linux
Viewing OBD-II codes on an RPi

Being able to adjust engine parameters would be amusing, although my understanding is that they're proprietary.

RPi Power Save

Haven't posted here for a while...no time!

Since I'm looking at running an RPi B or B+ for a HomeGenie server to drive a Z-Wave network, power consumption becomes an issue.  I started looking into power options.

This one Muslim dude (I wouldn't have known except the final comment in the post) has a page listing some of the options, which are to disable the USB hub/Ethernet, use the model A, underclock the core, and disable video output.  I hadn't realized that dynamic clocking could be used as power save; that somewhat compensates for the lack of sleep functionality.

The config.txt file is described at raspbians.com (which sounds like some strange flavor of lesbians...).  Actually, the official documentation is at raspberrypi.org.  The arm_freq_min, core_freq_min, and sdram_freq_min settings are used for dynamic power as long as force_turbo=0.

Edit [2016.01.24]: Using external hardware, it's possible to put the RPi into a suspend mode: Sleepy Pi and Witty Pi.  What I really want is something that'll go from suspend to active on network traffic (not WOL, which boots on network traffic).

Software TNC

From a ham friend: the Dire Wolf software TNC (forum) that can run on a Raspberry Pi or Beaglebone Black.  Sweet!

OwnCloud on RPi

Running OwnCloud on a Raspberry Pi (tutorial) seems like a very worthwhile project.  This will be a good application of the B+, with all those USB ports.

PiPhone and Others

Some random RPi stuff:

• PiPhone (and its maker's site)
• The RPi B+ 
• Arduino-powered LED Lighting 
• 3D-printed Gameboy look-alike

Google Voice on RPi with Incredible PBX

While poking around for Skype on RPi info, I also checked Google Talk.  It seems that video encoding is beyond the modest capabilities of the RPi, but there's already a voice application ported to the RPi called Incredible PBX.  There are a couple versions of this software for the RPi: Incredible Pi and RasPBX.  The original version of Incredible PBX used Google Voice to provide the phone number; I haven't checked into it enough to know if that's still the case.

Incidentally, Google has a page for developers on Talk, which includes information about how it uses XMPP and their extensions for voice.

As an aside, the Google Talk dev page links to the XMPP extensions page, which has proposals for IoT applications including sensors and such.

Skype on RPi

I was curious if there was a way to get Skype running on the Raspberry Pi--as a way of cobbling together a video call box.  Apparently it's possible to make voice calls (with the original forum post) using the binaries in the Skype developer's kit ($5 fee required), but there's no video support.  Somewhat of a bummer, but not entirely unexpected.  Perhaps Google Chat will come out with video support for the RPi since Microsoft has little incentive to port Skype video.

RPi Radio

I'd posted before about SDR, and have tried PiFM.  Why not put them together?  Apparently someone has done it, based on an article on Hackaday linking to a post on some guy's blog.  He uses it to transmit data at about 9600 baud.  I'm more interested in using this to transmit voice: basically getting a huge transmit range relative to normal HTs for a fraction of the cost!  The RPi is $35; the SDR dongle, $10; a small LCD display, $20; some filtering hardware and wire for the transmitter, $5; you'd need a USB mic and a LiPo battery to complete the setup.  Well, I've read that SDR hogs power, but even so, this could be really cool...!

I almost forgot, there's a TNC kit for the RPi available as well.  Although if the receiver's digital, that'd be unnecessary.

Displays for the RPi

I was bothered by the DSI port on the RPi that's going unused.  So I went looking for DSI displays and found via a forum that the RPi Foundation is working on one.  The guy who came up with HDMIPi did a preview.

Supposedly one will be able to use both displays at once.  Awesome!!

The "DSIPi" is to be 7" at 800x480, good enough for DVD video.  The HDMIPi is 9" at 1200x800; 720p, but not full HD.  I think the DSIPi will be good for a car video player project, but the HDMIPi will be good for keeping me from hogging the family TV!

Software-Defined Radio

Someday I'd like to get into this.

SDR @ Wikipedia
About SDR dongle hardware
SDR for $20?!
RPi as an SDR server