Kev’s Blog – Page 177 – Kev's Development Toolbox

April 19, 2016

Raspbian fsck fails on boot

I used

sudo touch /forcefsck

to set my Pi to run a fsck at boot, but it failed with this message:

"An automatic check (fsck) of the root filesystem failed. A manual fsck must 
be performed, then the system restarted. The fsck should be performed in 
maintenance mode with the root filesystem mounted in read-only mode"

I ran sudo fsck /dev/mmcblk0p2 – there was a couple of errors that required a ‘y’ to fix, and then it completed. Rebooted, and back to normal. Similar discussion on this message here.

April 16, 2016

Setting up an automated Raspberry Pi broadband speed monitor

Based on this Make article:

http://makezine.com/projects/send-ticket-isp-when-your-internet-drops/

Grab the scripts:

sudo apt-get install python-pip
sudo pip install speedtest-cli
git clone https://github.com/HenrikBengtsson/speedtest-cli-extras.git

Create an IFTTT account and add the ‘If Maker then Google Drive‘ recipe to your account. This step deserves further investigation… this is an incredibly easy way to integrate access to online accounts (Twitter, Facebook, Google etc) and trigger writing messages to them via a REST based api call. Very, very cool.

After you’ve done the above, while logged on to IFTTT, click Channels in the top right, find the Maker channel and click it, and you’ll find your secret key value to use in the next script.

Copy script from this Gist, modify to add your secret key from above setup:

https://gist.github.com/aallan/bafc70a347f3b9526d30

At this point you can follow the other steps in the Maker article to set up to run the script using cron, and you’re all set!

April 10, 2016

Scheduling scripts to run at boot on Raspbian (Raspberry Pi)

There’s always a dozen ways to do anything on Linux, and I was looking for a quick and easy way to run a script at startup on Raspbian on a Raspberry Pi.

I found this post:

http://raspberrypi.stackexchange.com/questions/8734/execute-script-on-start-up

which has a number of good suggestions, but the quickest and easiest approach is probably to add a @reboot entry to crontab, as suggested in this post here.

April 10, 2016

Amateur Radio related uses for your Raspberry Pi

Here’s a collection of Amateur Radio and other general radio related possible uses and ideas for using a Raspberry Pi. Some of these ideas could be used in connection with each other, or just solo.

This list is a collection of ideas for the basis of an upcoming presentation; more on that later. Right now, a collection of links for reference.

Simple:

as a simple/cheap Logging computer:
- CQRLog: https://www.cqrlog.com
- KLog: http://jaime.robles.es/klog/klog-intro/

Easy:

ADS-B aircraft transponder receiver (http://www.rtl-sdr.com/adsb-aircraft-radar-with-rtl-sdr/)

Slightly more involved:

APRS tracker (mobile APRS – ping beacon packets with location)
Software Defined Radio using RTL USB dongle and rtl-sdr (https://www.kevinhooke.com/2014/07/26/installing-rtl-sdr-and-dump1090-on-a-raspberry-pi-to-receive-ads-b-signals/)
CW progation beacon transmitter (http://hackaday.com/2013/01/25/raspberry-pi-used-as-a-beacon-transmitter/)
APRS i-gate (internet gateway for APRS data)
WSPR transmitter / WspryPi / TAPR Whispering Raspberries QRP Tx Shield

More involved:

Soundcard based Packet Packet TNC, using Direwolf: https://github.com/wb2osz/direwolf
Hardware Packet Radio using a TNC-Pi add on board
RadWav SDR transceiver add-on board $150: http://www.radwav.com/index.html
QTSDR – SDR transceiver (https://github.com/ha7ilm/qtcsdr)