FreeBSD identifying failed disk

Posted by & filed under Hardware.

Using the sas2ircu utility from LSI, we can blink the drive LED to help ID the failed drive correctly. Of course this requires a LSI card. Some LSI cards may need to use the sas3ircu utility instead. There have been some reports from the interwebs that this utility failed to blink the correct drive, but I have not experienced this myself.

As always use the supercomputer between your ears to ensure the physical serial and the serial reported by the system match, etc etc.

Back to the sas2ircu utility in a moment. We need to first acquire the serial number of the failed disk. For a system that is multipath, we can find the actual dev names by running the following to locate a disk in the fail state:

Now we can see da16 is failed. Time to get the serial number of that disk. Or da43. they are the same just multipaths.

Save that serial number for the next step.

Smartctl also outputs other useful information about the drive, statistics, etc. Worth checking out, but not relevant here.

Next, we can display the disks attached to one of those controllers. Be sure to input the correct serial number in the grep command:

Get the enclosure and slot # of the failed drive and turn the led on:

Turn the led off:

NOTE: If you are replacing a disk that is multipath, e.g. you see something like the following when you offline and remove a disk, ensure that the LED above is OFF or GEOM_MULTIPATH will not pickup the new disk as multipath. See the below log for what happens when a disk is inserted with the LED blinking Vs not blinking:



Posted by & filed under Adruino, Hardware, Hardware Development, Programming.

PlatformIO is an open source ecosystem for IoT development
Cross-platform build system. Continuous and IDE integration. Arduino and ARM mbed compatible


Came across this cool IDE, built on top of Atom for dev of iot. There is also a commercially supported offering.

OpenPilot – Open Source UAV Control System

Posted by & filed under 3D Printing, Hardware, Hardware Development.

OpenPilot is a next-generation Open Source UAV autopilot created by the OpenPilot Community (an all volunteer non-profit community). It is a highly capable platform for multirotors, helicopters, fixed wing aircraft, and other vehicles . It has been designed from the ground up by a community of passionate developers from around the globe, with its core design principles being quality, safety, and ease of use. Simplicity does not come with any compromises either: with no hard-coded settings, a complete flight plan scripting language and other powerful features, OpenPilot is an extremely capable UAV autopilot platform.

OpenPilot was started at the beginning of 2010 and is a serious use platform aimed at civilian and research purposes, with emphasis being placed on making the platform especially suitable for aerial photography and aerial video applications.

ESP2866 — WiFi for the Arduino

Posted by & filed under Adruino, Electronic, Hardware, Hardware Development.

This board is really freakin cool. It no only has a SoC chip that is essentially a UART to WiFi, it’s microprocessor is also programmable and has a PWM pin as well. On Arduino day, it was announced that the Arduino IDE now supports the ESP2866 making things a lot easier.


  • Article on the ESP2866:…
  • ESP2866 Forums:
  • ESP2866 Arduino Source code:
  • ESP2866 Breakout Boards:
  • ESP2866 on eBay:
  • Seeed studio ESP2866 Module:

Thermoelectric generators

Posted by & filed under Hardware.

Thermoelectric generators (also called thermogenerators) are devices which convert heat (temperature differences) directly into electrical energy, using a phenomenon called the “Seebeck effect” (or “thermoelectric effect”). Their typical efficiencies are around 5-10%. Older Seebeck-based devices used bimetallic junctions and were bulky while more recent devices use bismuth telluride (Bi2Te3) semiconductor p-n junctions and can have thicknesses in the millimeter range. These are solid state devices and unlike dynamos have no moving parts, with the occasional exception of a fan.…

TEG Suppliers……

Prey – Open Source PC/MAC/iOS/Android Anti-Theft

Posted by & filed under Hardware.

Now this is cool — a open source anti-theft system for your laptop, iOS, or Android device.

From the website: Prey lets you keep track of your phone or laptop at all times, and will help you find it if it ever gets lost or stolen. It’s lightweight, open source software, and free for anyone to use. And it just works.

git Repo:

Wi-Fi Protected Setup Vulnerability

Posted by & filed under Hardware, Networking, WiFi.

The Wi-Fi protected setup with which a large majority of new routers ship with enabled by default has a serious flaw opening it up to a brute force attack against the WPS pin. Additional flaws allow for a successful brute force attack in 11,000 attempts. This means the network key of a protected network can be retrieved within hours.

The best course of action right now is to disable WPS if possible. This is not a option on all routers, but the possibility may exist of re-flashing the router’s firmware to a different one such as Open-WRT, DD-WRT, Tomato, etc. to disable it.

CERT’s Release:
Vulnerability Technical Details:…
Reaver — Functional exploit:

4:3 and 16:9 Screen Resolutions

Posted by & filed under Hardware.

List of 4:3 Monitor Resolutions
Resolution – Aspect ratio


List of 16:9 Widescreen Resolutions
Resolution – Aspect ratio


List of 16:10 Widescreen Resolutions
Resolution – Aspect ratio


Bridging Amps and Ohm Loads

Posted by & filed under Audio, Electronic, Hardware.

Amplifier bridging is simply using 2 channels of an amplifier to drive a common load. For 2 channel amplifiers, one left signal and one right signal is used to drive a mono speaker load. Keep in mind that mono and bridging are not necessarily the same. Mono means that there’s only one output signal. There could be more than one speaker but each speaker will have the same output. Bridging means that you are using more than one source of power to drive a load (speaker). The sources of power are one each output from either channel of the amplifier. A long time ago, amplifiers had signal on the positive output speaker terminals only. To bridge one of those amplifiers, you’d have to use some means to invert the signal on one channel (remember the old ‘bridging modules’ for Orion amplifiers?). Today’s bridgeable amplifiers have an inverted channel as part of their design. For many amplifiers, the left positive and right negative are are the signal outputs. A few use the left negative and the right positive. Others still (mostly mono amplifiers that are to be used in bridged pairs) require that you choose 0° or 180° via a switch to invert the signal.

Configuring Wireless in Windows thru the Command Line

Posted by & filed under Networking, WiFi, Windows.

So using the netsh wlan command allows us to manipulate the various properties of a wireless connection. Other potentially cool stuff:

  • netsh wlan set tra yes – Enables wireless debug traces in %WINDIR%\tracing\wireless
  • netsh wlan
  • Creating/moving wireless profiles quickly
  • There is more, but this is prolly what I need to use when I write a app for a client to view wireless connection status.