floodgate.blog

I have yet to make my LCD produce any sort of signs that it’s alive… so I ordered a new LCD.  I did finally decide to downgrade a bit from a 20×4 character display to a 16×2 character display.  I was always annoyed by the size of the LCD I had and this will correct that problem.  I also switched to a negative LCD (meaning the background is black and the characters take the color of the backlight — in this case, white) which will look nicer with the LED bars and indicators (or, so I think).  While I was at it, I picked up a few more parts (and thus reignited a couple dead parts of the project)…

1. Picked up an FM receiver board — I always wanted to include one just so that the box itself would only need amplification.
2. Bought an iPod connector — yay?  Mad props to the iPod Linux project and ladyada for very helpful information on the connector and charging circuits.  Intending to run Audio L/R, and the charging circuitry (looks like 5 wires… great… don’t have one of those — should be a ghetto-fabulous wire!)
3. Picked up a RBBB Arduino and a Sanguino so I can stop this bullshit of “hey, if I had a sanguino…”.  I don’t think I need the sanguino for this project.  I am intending for the RBBB to be semi-hard-wired in the box for this one.  Plus I picked up a BUB board (the one that connects the TTL to USB for writing the sketches/code to the chip) with em so I can just buy the cheap kits now.  Yay!

As far as project status — it’s alive and sluggish.  It’s really difficult finding time.  I have so much soldering to do that it’s somewhat intimidating.  I also need to build/verify the VU meter circuit with the 3915’s.  I’m actually putting the code off until the very end.  While I was sketching the hardware diagram for my project, I also took the time to see how much power I would need to run the whole shebang.  Looks like I’ll need three 5V rails (one for the arduino and hardware, another for LEDs alone, and one for the iPod cable) and a 3.3V rail for the FM module, real-time clock, and the logic level converters (also bought today).  At peak, this lovely car-puter will be pulling over 2 amps (scary shit right there), close to 800mA for LEDs alone, another 1 A for the iPod cable.

As you might have figured out, I’m avoiding the code.  But, code related items so far: I will be debouncing switches in code as opposed to via hardware (cheaper, and my code will not be very complex so I can spare the CPU cycles).

Lingering items — the real-time clock will need to be powered when the unit is off.  OR, it needs a battery backup.  I have the parts for a 3V lithium battery but haven’t figured out how to have it switch to battery from main power when the box is shut off.  That’s semi-important to using the RTC to its fullest.

And that’s all… for now.  New parts should arrive just in time for me to leave the house again (figures!)

I bought a base set of parts last summer — arduino, 20×4 LCD, and big resistor and capacitor packs.  I started dreaming, then work/life got in the way.  So, most of the parts sat for a year…….. doing nothing.

My LCD appears to be dead — it was sort-of working for a while (displaying partial garbage, partial correct characters (but in the wrong place)… then it decided it didn’t need to do anything.  I am not sure I’ve even used the thing for more than an hour of total “on” time.  So…. I’m going to redo the wiring on the LCD board to see if I didn’t screw something up in the last day or so.  If/when that fails to help, it’s on to buy a new one.  I’m eyeing a 128×64 display at adafruit… except taht it requires a little more OMPH than the base arduino has (in terms of memory at least).  So… the “do I get a Sanguino or Mega” discussion is now back.  Yay?

Regardless, I’m still pissed that my display is dead… grrrrrr!!!!!

While my blog has been mostly dormant all summer, I have not.  If I ignore those little people (one of whom is starting to crawl now… eek!) that take up plenty of my time (it’s hard to ignore them… they’re loud!), I’ve still managed to get some things done.

Carduino

My car computer based via arduino has not progressed in terms of building or testing, but I’ve managed to pin down a few things that I want to include, and have some a TON of research into additional circuits I will be incorporating.  The biggest thorn in my side has been those darn SOIC-20 chips.  I did a lot of reading on how to solder surface mount components (of which the SO’s are the biggest) and the best articles and how-to’s always included a PCB to solder the IC’s to.  So, I started reading about how to etch my own PCBs or send them off to a PCB fab house.  While etching them myself wouldn’t be horribly difficult or expensive, I just can’t see the “Hey honey, I need to buy some muriatic acid” talk going well with my wife.  I investigated options in sending my design off to be printed elsewhere — there is a great company through SparkFun that’ll do production runs of “one”.  The cost isn’t too high, but the turn around time is completely dependent on how busy they are.  Then there is one nagging details….

I need a printable PCB design to do either of these.

This is usually where this line of thought ends.  I don’t really have the patience (nor the need) to bust out a schematic, then PCB the thing, then make the board.  I’ve settled into a simpler domain that involves breakout boards meant for breadboards (specifically for those pesky surface mount guys) and lovely perf board from radio shack.

Some things I will be adding that have zero direct connection to the arduino… I will be adding a VU meter for all outgoing audio.  I discovered the LM3915 chip the other day and have read through dozens of posts about circuits doing exactly what I want to do.  The question now comes down to what color LEDs would I like to use.. hrmm.  The second will be a strobe that is much like what you would see in a car with an alarm system: short pulse, long delay.  I finally sat down with a 555 chip and figured that shit out.  I still don’t really understand it, but the math works.  I am long overdue for a post that includes links, but the one I used to help me through the 555 circuit I will definitely share soon!  I’m running a 10% duty cycle flashing LED circuit right now (the short pulse is still almost 1/5 of a second… big honkin’ resistors in this puppy right now).

After that… not much.  I’ve had this ever evolving and shrinking shopping cart on digikey and sparkfun for a while now.  I can’t ever seem to decide what exactly it is that I want to accomplish.  I keep coming back to wanting a compass then running away due to the cost — a 2-axis compass chip is semi affordable.. with tilt compensation (a requirement for me IMO) is completely out of price range, and a GPS is the middle ground (direction, altitude, speed.. it’s got it all.. and I could get it for around $50-60).  It’s a never ending struggle.  I know I want it in v1 of my project… just not sure I want to wait around long enough to have the $$$ for it.

Software / Mathiness

I abandoned my hopes of a self-hosted learning environment, a grading program that will bow to my every command, and any other such ideas I may have had.  I just don’t have the time.. and 2/3 of what I was trying to accomplish was me replicating available packages and trying to find ways to make them better.  I’ll take the “I’m going to pretend I know nothing about technology” route on these and just use what is available.  I suppose this falls under mathiness (a-la Colbert’s Truthiness) since they were all “math” related.

Next Project(s)

This one is a ways off.. but I have decided I want to build my own custom guitar amp.  I am not really sure how I will accomplish this yet.  I might opt for the kit approach due to my previously discussed lack of interest in busting out a PCB.

I also plan to create a semi-portable workbench for my soldering and electronics endeavors.  I found many great articles on how to have highly functioning and mostly-professional equipment and facilities for very little money.  Again, many links coming at some point (I routinely visit about 20 different sites when coming up with my plans for these things… eek!)

Another project that is a definite GO but is on the backburner until more funds are available is an RGB switcher with component upconversion.  I’m planning for it to be 4 ports of video+audio (2 ch) to be connected to a 22″ – 24″ LCD computer monitor (hence the fundage).  It will be arduino controlled with a VU meter (truthfully, it’s a scaled down version of the carduino only the bus for the sources is MUCH bigger… 2 channels/source in the car vs 7 channels/source in this one).  It will have one button that will cycle the sources which will be displayed on a 2×16 character display with black background and amber foreground.  This project is definitely concrete — it will use (more or less) the same code as the carduino, same parts as the carduino, and will serve a similar purpose.

A potential addon to both the carduino and the rgb switch is a fading LED (a-la mac in sleep mode).  I can’t decide whether I care enough about this or not to go through with it in the carduino project.  With the VU meter and indicator lights already (talking 24 LEDs minimum), there may not be any real estate left!

That’s all folks   I know I know… ramble on…

I’ve been quite slack with my blog and, while that annoys me to no end, I still hope to write SOMETHING meaningful on here.  So, here’s what I’ve been working on and where it (hopefully) is going.

1. My car project continues to be the one I want to complete.  I spent the better part of an hour trying to solder a SOIC-20 by hand to some old ATA33 cable.  I’d like to think this exercise was a success.  I won’t really know until I test it.
2. My educational software hub (will talk about it once it’s completed) has been on hold but is definitely on the block for this summer.  I was demoing different learning management systems and think I’m settling on Moodle.  I need to discuss available options within my school before I commit fully to my own installation.  There are other things I’m hoping to get up and running but honestly at this point I’m not even sure what they are yet… figures!
3. I’m taking the summer off from employment.  I’m going to take on any number of small personal projects and play with my two kids.  This is the part I’m most excited about.

ciao.

As is always the case, my (what I consider to be) good ideas always appear at the worst time.  My best song recordings always took place on the night before a final exam in college, a better idea for a project always came about while I was in the middle of a different one, and then there’s the dreaded situation: having projects that are related and semi-dependent on each other.  This is where I am now.

While I don’t really consider any two projects dependent, they are related to similar fields or ideas.  For example, I am designing & planning both a document camera, a grade storage system, and a lesson planning system all for teaching.  I am constantly expanding and contracting my “car computer” project (right now on the edge of a massive expansion).  In the end, this is the norm for me and I’ve already learned to just accept it.

So, where does that leave me?  I find myself learning about Python and wxPython.  I find myself searching through the Digikey catalog for hours on end looking for just the right part for the job.  I find myself wanting to build my own “arduino” clone because.. well.. I just want to.  I then remember all of the rest of my life that I have to tend to and all my ideas fade into nonexistence.  I am often questioned about why I don’t want to go anywhere and do anything.  The answer is simple: if I don’t go anywhere, I might have time to get started on SOMETHING… anything…

Or, I could choose to accept that I can come up with ideas that will never be realized.  Every now and then one of those ideas survives……….

Here’s my current (mental) path from design through production.

1. I have a POS webcam from about 9 or 10 years ago that still somehow works.  That will function as my prototyping camera.
2. Once I cam prove that this works, I will be buying a HD webcam (looking at the MS LifeCam Cinema right now, also I will look at anything that will do 720p video capture at 30fps) and adjusting or rebuilding the support structure.
3. If I survive at this point, I’ll give it a live demo run in a classroom setting.
4. If it goes well, I’ll spec it out in terms of something that could be built to order (mostly from a cost standpoint) and see if I can turn this into a fun summer project.

Some drawbacks that I see coming.

1. This idea of mine is best suited for a Windows environment (which my school is not…).  I would need to dive into Macam and pick webcams that are reliably supported before I pitch this for real.
2. This rig REQUIRES a computer.  While I could bypass this by using security cameras instead of webcams, I just don’t wanna.
3. Like I mentioned in the previous post — having the doc cams is one thing, but having enough display devices is another.

Even still, I’m excited about this one — most of my projects are “want” based, whereas this one is applicable to a broader audience and has the potential to become a “need”…. I’ve thought about buying my own projector and Elmo for a while.. this might be a nice (and absurdly cheaper) alternative.

It’s not really a new idea (google returned an instructables link as the first hit, which in my universe means AWESOME!)… thinking ahead to a time when I will have access to such items as a data projector in my classroom (yea right!), it would be awesome if I had access (mostly permanent access) to a document projection camera like the Elmo’s that are everywhere.  One of the people I follow on twitter posted how her students referred to a doc cam as just a web cam looking down — and there’s my project.  At the lowest level, the document camera would simply need to be mounted and facing down and fed to some sort of display device (tv, projector, etc).  Given that most cheap cameras (think cell phone cameras here) pretty much suck ass in low light, a strong light source is needed ($5 desk lamp anyone?).  Realistically, a basic document camera could be put together for about $30 of parts and an hour or two of time.

This of course does not fit my model of “go big or go home” when it comes to personal projects.  I’ll be using a USB webcam and connecting through a laptop.  In my head, I think of this as a nice compromise between functionality and price.  I can switch from video to powerpoint to web to whatever on the computer while also recording the video feed, taking screen captures, and so on.  The biggest draw for me here is the price and availability — I can pop into a walmart and pick up a baseline webcam for $20 that will do the trick.  A $5 desk lamp doesn’t appeal to me since I’ve build high-brightness LED bars before.  Even at this point we’re talking about a comparable price and.. well.. cooler looking lighting.

Building the support structure for the camera is where I envision problems.  Ideally I would want this to be as unobtrusive as possible.  Since my experience only pertains to working with lumber/pine, it would look clunky.  Since this is what I’ll use anyway, that will be a big challenge.  I’ve been big on 1″x2″ lumber lately so that will be my base.  Ideally the writing surface will be very firm (meaning NOT pine) and stand out from the rest of the mount.  I am undecided on the placement of the lighting — either left & right of the camera facing straight down, or from the left and right down near the writing surface.  I’ve seen & used both types before and couldn’t really pick one over the other.

Looking forward, if this project produces results that will be acceptable in a classroom, I might consider building a few for my school to see if this will become an adopted technology.  This is all dependent on other factors…. like having data projectors in the classroom (something that is chronically under supplied in my opinion — through no fault except budgetary goodness).

The next step will be to start prototyping — I’ll need a web cam and will need to test focus and readability at various distances to determine how big the structure needs to be.  Next I’ll need to find a way to build the mount and supports in such a way that will be sturdy, functional, and not an eye sore.  If I make it here, I will have a working device and might try it out one day unannounced.

So… yea… not much to write.  I completed my transition from mac to PC with few hitches (mostly font problems on typed documents), I have yet to touch any of my projects (to the point that I had to go back and read what they were), and am exhausted pretty much all of the time.  Like my students, I am also counting down the days (I have to add 3 to their number though… grrr).

So, this summer I plan to.. well.. do nothing.  I can’t see any time materializing itself to make way for my arduino conquests (pretty much numero uno on my list right now), and with starcraft II coming out on july 27th…. yea, that’ll be my summer.

Boring post… sorry.

Since I am how (half) convinced that Ubuntu 9.10 hates me (more specifically my computers), I ventured outside of my usual box and drifted back to Debian for an install I’m trying to make sane.  My wireless card only lives/breathes under ndiswrapper… so here’s some frustration: I grabbed the necessary (in ubuntu at least) packages and stuck them on a usb drive and dpkg’ed them in.. only to find out that I need to “download” stuff to make my wireless card (the thing that would be doing the downloading) work….

time to find a long ethernet cable I guess… hmph!

I’ve been busy creating and updating my new-ish projects wiki with my car project.  I find that I think about the project entirely too much (especially in the ‘I could do that…’ realm) and I am constantly revising hardware & software specs and my own expectations.  My biggest issue lately has been how to effectively control the devices I need to control.

My baseline thought process is simple: any pins on the arduino itself should be treated as gold — anything that can be moved off board.. well.. should!  Writing to the i2c bus is (mostly) straightforward and with the plethora of I/O expander chips I have (and others I may buy), anything that is a “receive only” (like the main LCD (parallel), LED indicators, and the enable lines for the audio bus) is being dumped onto an expander chip.

Either way, I was stuck with writing a library to deal with the nonsense of moving a device or design component from the arduino pins to external pins on the i2c bus — either I had to code some sort of polling routine for button pushes (barf!) or hack the LiquidCrystal library a bit so that its writing commands are no part of Processing/Wiring but via serial/i2c commands.  So, that’s where I am — I am hacking a copy of the LiquidCrystal library so that all functionality is the same (from an API standpoint I suppose) but under the hood is the semi-chaos that is i2c communications.

I’m glad I’ve started coding — the projects wiki has hands-down been the best thing I’ve done to date.  I’m semi-organized, things are written down, and most importantly: I WROTE DOWN HOW IT WILL BE WIRED!!!  I might actually breadboard this thing before I start soldering again… what a thought!