Building the $100 night light, Part V

Finishing the "Building the $100 night light" series, Part V focuses on final assembly...

With all the design work done, it was time for final assembly.  Unfortunately, I did not take enough photos of the work in progress, but did capture one right before the lid was attached.

All of the components fit well on the PCB, with only one major flaw.  The large capacitor in upper middle part of the board was too tall for the Hammond enclosure.  Live and learn - for the next hobby project, I will need to pay more attention to available heights.  Rather than attempting to attach wires onto the leads and glue the cap somewhere else in the case, I settled for soldering it high on the PCB (lots of the leads above the board) and folding it over -- not pretty, but it works.

For the LEDs, I soldered wires onto the leads and crimped connectors on the other ends to attach the components to the PCB.  While searching for the appropriate drill bits to use for the 5mm and 10mm LEDs (I do not have a metric set), I came across the following site which had a convenient table.   For the 5mm I used a 3/16" bit, and for the 10mm I used a 3/8" bit.  Each was a little to snug, but angling the drill a bit while drilling gave enough gap to fit the LEDs properly.

Finally, the PCB was attached with 4-40 screws to the enclosure, and the lid attached.  See the below picture for the final night light.

Where the project cost a ridiculous amount compared to a store bought item, it was a great educational project and had just enough complexity to hold my lab assistant's interest.

Building the $100 night light, Part IV

Continuing with the "Building the $100 night light" series, Part IV focuses on the building a PCB in Eagle...

Before starting the process of designing the board, I selected a fabrication house that I would use for manufacturing.  This is done up front because every manufacturer has different tolerances and costs.  After some research I selected Sunstone Circuits, a manufacturer in Oregon.  Sunstone publishes a set of Design for Manufacturing (DFM) rules and CAM files which can be downloaded here, and installed in Eagle to help validate your design as you work and generate the final GERBER files.

While in Eagle with the schematic open, I switched to the board view, which creates a new board, inserts all of the schematic components, and connects the components with air wires.  For this simple project, I used a 2 layer board (top and bottom).

The first step was to resize the board to dimensions that would fit within the Hammond ABS enclosure, followed by moving the components onto the board.  I used the Eagle Autorouter tool to create the initial set of traces, and then tweaked a few of the runs by hand.  As the final step, I created a ground plane on the top and bottom layer of the board.  The final board layout is shown below.

The last step was generating the files needed by Sunstone Circuits.  Sunstone had an excellent writeup on the process, in a PDF file titled "EAGLE v5.0+ Board Convert to Gener Made Easy".  The process outlined in the document was followed, and worked without issue.  The major steps were:

- Change Eagle font usage, by chosing Options |  User, and selecting "ALWAYS VECTOR FONT"
- Run DRILLCFG.ULP to generate the DRL file
- Run the CAM processor, EXCELLON.CAM job, to generate the NC drill file
- Run PROCESS JOB, 2LPlus-Sunstone.cam, to generate the GERBER files
- Zip up the files created in the above steps (the zip file contents are listed below):

This file was uploaded/ordered to the Sunstone website, and within a few weeks I received the manufactured board (photo below).  The total cost for the board was about $30.  In hindsight, I would have ran a number of the traces differently to make soldering easier.

Building the $100 night light, Part III

Continuing with the "Building the $100 night light" series, Part III focuses on the building a schematic in Eagle...

After breadboarding the components, the next step in the design process was to create the circuit schematic in software.  The application used for this was the free version of Eagle PCB.   Since I was new to the software, I did some googling and found an great series of basic tutorials on YouTube by RCP Electronics.

Designing a PCB is a two step process in Eagle.  You first create a schematic to layout the components and connections, then create a board from the schematic.  Using Eagle was fairly intuitive, except for finding the components to add to the schematic.  After some research, I settled on the following components in Eagle:

PINHD-1X2/90 (for the 90 degree 2 pin headers)
R-US_0207/10 (for all 1/4 watt carbon film resistors)
DIODE-DO41-10 (for the 1N5819)
C-US050-025X075 (for C1)
CPOL-USE5-10.5 (for C2)
DIL8 (for TS555CN)
GND

These components were added to the schematic and connected using the wire and junction tools.  The Tools | Erc menu option was used frequently during the drawing process to ensure that all connections were valid.  Since the enclosure for this project was not conducive to placing all components on the PCB, 2 pin headers were used on the schematic so that the devices could be connected from a distance to the PCB.  The final schematic is shown below.

Once the schematic was completed and contained no errors, it was time to move to the PCB creation process.

Convert Oracle Weblogic 11 to a Windows Service

In most instances, development application servers are installed to be started manually.  For those occasions when a development AdminServer needs to be converted to a Windows service, the following process can be used (unfortunately, the normal use of the Windows SC.EXE application is insufficient for WL).  Thanks to the original source at Weblogic Wonders.

To convert an administrative server, create a command file (.cmd) containing the following code (modified as needed), and then run the script, preferably using admin rights.

SETLOCAL set DOMAIN_NAME=Wonders_Domain set USERDOMAIN_HOME=c:\bea\user_projects\domains\mydomain set SERVER_NAME=AdminServer set WL_HOME=c:\bea\wlserver103 set WLS_USER=weblogic set WLS_PW=weblogic set PRODUCTION_MODE=true set MEM_ARGS=-Xms1024m –Xmx1024m call “%WL_HOME%\server\bin\installSvc.cmd” ENDLOCAL

If the script ran to completion, there should be a new entry in the Control Panel | Administrative Tools | Services application to control your application server.

Building the $100 night light, Part II

Continuing with the "Building the $100 night light" series, Part II focuses on the parts list...

The parts for this project were sourced from Mouser Electronics.  The original list of parts from the Red Circuits schematic was left mostly in tact, with a few minor changes.  For example, the 1M resistors were scaled down to 100K, in order to switch this from a visibly pulsing light to one that appeared solid (flashes faster than your eye can detect).  I also added a case and some screws needed for the final assembly.

At the time of writing, the parts totalled about $15, with $12 being sunk into the ABS enclosure from Hammond.  The enclosure cost was a bit high, but it was exactly the right size, and looked sturdy enough to survive some rough handling, so I decided not to shop around.

The final list is as follows:

Parts List:

2 x [291-100K-RC] Xicon 100K Carbon Film Resistors
1 x [696-SSLLX100133SRD] Lumex 10mm LED
1 x [291-47K-RC] Xicon 47K Carbon Film Resistors
1 x [546-1599BBKBATCP] Hammond Enclosures ABS 5.12 x 2.56 x 0.97
1 x [782-TEPT5600] Vishay Photodetector Transistors Ambient Light Sensor
1 x [871-B32529C104J] EPCOS Polyester Film Capacitors 0.1uF 63volts 5%
1 x [647-UKL1E221KPD] Nichicon Aluminum Electrolytic Capacitors 25volts 220uF
1 x [512-1N5819] Fairchild Schottky Barrier Diode
1 x [511-TS555CN] STMicroelectronics 555 Timer
1 x [546-BH1AAW] Hammond Battery Holder AA
4 x [534-3368] Keystone Fiber Washer .250"OD
2 x [534-9401] Keystone 3/8 4-40 Steel Screw

Building the $100 night light, Part I

As a first "basement electronics" end-to-end project, I wanted to find a circuit easy enough to involve my child as a lab assistant.  To move the process along, we used Google to find a basic circuit as a starting point, and settled on the following from Red Circuits:

Battery Powered Night Lamp

This circuit uses a 555 chip to pulse an ultra bright LED while powered by a single AA battery.  It also contains a photosensor to disable the LED during the day (battery conservation).  With a component count of around a dozen, it had just enough parts to be interesting, but not too many to lose my lab assistant's attention.

The plan for this project was simple: to build a self-contained/usable project that doesn't look like it was built in a basement (well, at least not have wires hanging out of it/etc., at the end of the day, it still looks cheap).

This project involved the following steps: finding/updating a circuit, identifying/purchasing components, using a breadboard to connect the parts, designing a permanent PCB, using a fabrication house for PCB manufacturing, then finally soldering and assembling the product.

During the course of the project, I estimate the expenses ran about $100.  In real world terms, this is an absolutely ridiculous price for a nightlight which could probably be purchased on Amazon for a few bucks.  However, the goal of this project was mostly educational, so the project costs were not meant to be comparable to an off-the-shelf project.  The costs also included a number of tools I didn't own, which are obviously one time costs which will reduce the costs of future projects.

This project took about a month to complete.  That is an end to end time, from research to final product, which includes slack time such as waiting for FedEx/etc.  The final product is pictured below:

Over the next few posts I'll document the entire process.

Status checking a 3ware 9590SE

A recent power outage took the home server offline while I was out of the house.  The APC battery unit appeared to do its job and shut the server down, but after restarting the server, I wanted to check the status of the RAID (a legacy 3ware 9590SE running RAID-5 with 2TB of space under Windows 2008 Server).  Upon running the normal 3DM2 tool (which has been working for years), I was greeted with the following:

After trying a few things (stopping/restarting service, checking the firewall, verifying the port is active with netstat, etc.), it became clear that the 3DM2 tool just did not want to function properly anymore.  Looking for alternatives to check status, I came across a command line tool in the install folder (tw_cli):

 

After browsing though help in the tool, I found the following commands which did exactly what I needed:

//SERVER> /c0 show
//SERVER> /c0/u0 show

Each of the commands also had a corresponding show all variant which dumped even more data,  but as the snapshot below shows, the show command gives a good basic overview of the device.

ASUS VE276Q Monitor

My small laptop screen just did not have enough real estate for reading the small print/graphs on datasheets; The workshop desk needed a monitor upgrade.

After a bit of surfing on Amazon, I decided on the ASUS VE276Q Monitor.  Like most products on Amazon, the reviews were all over the map, ranging from glowing reviews to "its the worst monitor ever manufactured".  I tend to throw out the top and bottom 10% of reviews, and go with the average.  This processed served me well again; The monitor has a great picture for its size.  The 1080 pixel vertical screen resolution is a bit disappointing (I'm used to the Dell 24 inch @ 1200px), but it seems that most reasonably priced monitors top out at 1080 these days (lousy HD specification).

The monitor has a fairly large stand footprint, so I bought a VideoSecu Wall Mount and got the monitor off the desk surface.  I had never used a product from this vendor, but found the wall mount to be surprisingly sturdy for the price.

BEFORE

AFTER

Using the TEPT5600 Ambient Light Sensor

The Vishay TEPT5600 is an ambient light sensor that can be used to replace Cadmium Sulfide (CdS) photo resistors.

Per the datasheet description, the TEPT5600 is a silicon NPN epitaxial planar photo transistor in a standard T-1 3/4" plastic package. Peak of responsivity is in the visible spectrum. Infrared spectrum is suppressed.

Vishay Semiconductors
Model TEPT5600
Mouser Part Number: 782-TEPT5600
Data Sheet

Usage:
(R1 will vary based on project needs)

Other links:
Phototransistor Circuit And Symbol Configurations
Digi-Key Training Ambient Light Sensor Module