Laboratory B Burlington's Community HackerSpace

13Feb/150

Emergency Power

Posted by Chad Loseby

10957720_594803736637_7918288386385030315_nA few Lab members recently asked me "how do you survive power outages?"

Here's how, and it's all available at your website or department store of choice (cough cough Amazon, Wal-Mart)

One (1) marine deep cycle battery, as large as you can afford
and/or can carry (approx $80) (must buy in store)

One (1) 12 volt trickle charger (approx $30)

One (1) 12 volt to 120 volt inverter, sized according to your needs. 200 watts will power a few devices for around $40; do yourself a favor and get a 600 watt Tripp Lite or similar, around $90

Optional: One or more 12V accessory plugs, to wire into b10988927_594803641827_8314235716196964016_nattery (approx $10/ea)

My current "Power Box", pictured below, is currently out on an off-grid island staged and waiting to run some Civic Wireless customer premises equipment. The box will run network gear on a small inverter for weeks on a full charge.

Part 2: Exploring solar trickle charging.

Questions? Email: help [at] civicwireless.org
--Chad

16Sep/130

Explain Shell

Posted by Jesse Krembs

explainshellWhen you first start using Unix based systems you quickly learn about the wonderful world the Unix command shell. One of the first commands you also learn about with "ls", "cd" and "cat" is "man". Man is short for manual and almost all unix commands come with a man page. Manual pages are usually quite informative about what the command does and all the options, but sometimes it's really hard to sort out. This can lead to trouble and frustration (boo!)
If you're anything like me you might occasionally have a problem with your computer and someone will tell you to run some command with a bunch of flags.. say "iptables -A INPUT -i eth0 -s ip-to-block -j DROP " or "rm -rf /" now you could run this run this or you could pass it to explain shell to help you sort out exactly what a command does. This is also really useful for commands where input is piped from one command to another.

Also check out this article about copy and pasting from the web.

Filed under: fixing stuff, fun No Comments
6Sep/130

Soldering Workshop:Fix a phone edition!

Posted by Jesse Krembs

Potential new member Charles stopped by the Laboratory to use the soldering station. Seems he tried an external antenna on his Samsung phone and the connector broke on him. This external antenna connector bypasses the internal antenna, so when it broke the phone could no longer use the 4G LTE antenna! Thus Charles was stuck with only 1x service (teh suck!). Charles used the Labs microelectronics station to desolder the broken connector. He then bridged the circuit with a bit of wire. Service went from 1x to 4G with 3 bars with this simple fix.

2013-09-05 18.36.30

After the MCA connector was removed.
Click to expand.

2013-09-05 19.21.12

After the connector was bridged with a bit of wire.
Click to expand.