With Wings As Eagles: Tech/Computer/Electronics Entries

And...we're back

2012 December 23 23:50

Getting my blog back up to speed has been on my to-do list for more than 3 years. As of tonight, it's done. All my blog entries from March of 2005 through the present are all here in one blog. The photos work, links work. Long live the blog, etc.

I started out using the blogger platform in 2005. It was (may still be) a great platform. I'd already established my own web site at craigsteffen.net, so I quickly figured out how to get blogger to generate entries and export them via auto-magic ftp to my own site. That arrangement worked fine until...I think it was late 2008.

I think it was that year that blogger announced that they were going to discontinue the external-ftp service. So I decided to set up a different blogging software. I looked over some of the packages available, and I decided that pivot was what I wanted to use. It stored its files as flat files on disk, but could be configured with menus and stuff.

I was able to pull most of my old blogger entries into pivot, sort of, but the images never quite worked right. And I discovered that I couldn't make pivot do categories of posts, which is one of the things that I really wanted to work. So after a short time, I decided that it would be easier to just write my own software rather than trying to get someone else's to do what I wanted.

So I've been working on a set of php and perl scripts in my free time for the past couple of years. The blog that you see here is the result. Up until the past few days, the last time I spent serious time working on it was a year and a half ago, the summer 2011. Starting in August of 2011, I've been working on a different bigger project, mentally I've been busier and had less left-over concentration to work on my blog scripts.

However, I've been working on it a lot in the past four days here at my parent-in-law's for the holidays. Thursday and Friday I posted 8 entries that I'd been meaning to put together for the past few weeks. Yesterday and today I've been working on hammering out the script that converted the original export file that blogger created for me in 2008. Today I finally ran that and it was able to pull all the 450-odd entries that I'd had in the old blogger blog. This evening, while watchin football, I ran the script that converted the pivot entries, and also the one that converted the blogger entries. The embedded photos were located in different directories, so I had to carefully combine the two sets of entries to get everythin to work right.

So there might be a few nits here or there, but as of now, I have all the entries from all three major phases my blog has gone through, all working and indexed using the main interface, the one I wrote. It's a bit clunky, but it works. There are the originall bloggger entries, the pivot entries, and the current flat file blog entries.

Happy Holidays, everyone! And happy blogging. :-D

Relays and diodes

2012 December 21 23:28

One thing I really like to have in a car is a warning buzzer than tells me when the headlights are on when I open the door, so that I don't leave the lights on and drain the battery.

My vintage Beetle never had such a circuit. It did have a buzzer that would buzz if you left the key in and opened the door. And it also turned on the dome light when either door was opened, independent of anything else. However, the switch to make both of those things work independently is a switch you can't get any more. It's a double-pole switch that switch the circuits independelty, and neither of them to ground. The only switches you can get for the doors are single-pole grounding switches. So the circuit to do all of this with a single switch per door gets a a bit more complicated.

I've designed a circuit to do the job. I want to have the buzzer go off if I open the door and any of the following is true:

And also the interior lights to work properly; that is, it goes on when either door opens.

Here's the circuit; two relays (they can be small ones) and four diodes. Now I just need to get all the connectors organized and the wires run, and the componnets wired up.

The only problem with this is I haven't been able to figure out to wire the relays so that if either the door is opened or the key is in, there isn't current being drained from the battery. Ideally it would only draw when both were true. But for the moment, I'll have to put up with a bit of current draw when the door is open, even if the dome light is turned all the way off. That's probably not that big of a deal.

What you find on the floor...

2012 December 20 20:51

I mostly don't talk about my job here, but I think I've mentioned that I go to a big computing conference every year. This year the Intel booth had a really great exhbit--they leased (or something) the real live original bridge set from the original Star Trek series. If you went to one of their talks, you could go and hang around the bridge and take pictures and stuff. I'm going to post a couple of the pictures here, to have a record of it.

Mr. Sulu's helm station on the bridge.

The navigation console on the bridge.

Hey George, I'm in your spot! :-D

This blog post expires on...

2012 December 20 18:59

The new plane has two GPS navigation units. I don't think I would have made that choice in configuring it, but it will be fine for the moment.

GPS units used for IFR flight must have current navigational and waypoint and airport information to be legal. The unit itself lives in the panel in the airplane, but the navigation data lives on a flash-memory card that sits in a socket in the front of the unit that's removable.

The information is updated every 28 days, so you need to remove the card from each unit and program it with the updated information. Most people have two of each card, and swap them out every time the information is updated. The seller of my airplane had two cards for each GPS as well, and a programming unit that will interface with either type.

There's a company called Jeppesen that packages the information into a form that the GPSs can understand. I downloaded their software and bought one update for each of the two GPS units in the airplane:

The older of the GPS units is an Apollo GX-60. It was designed by a company called "II Morrow" which has since been absorbed by Garmin. This one is an old-school unit; its screen is monochrome and it has an older-style interface. Its memory card is a PCMCIA memory card. PCMCIA is a expansion bus that used to be used by laptops a lot. Here's the Jeppesen programmer writing data to the GX-60 card:

The other GPS is a Garmin 430W, a relatively modern GPS unit (6 years old or so). It has a multi-color screen and a relatively modern interface. The data card for the Garmin units is a proprietary card that's only available from them.

Laying in supplies

2012 December 05 23:36

Boy, it's been a busy month at work. We have a big review tomorrow and Friday. A lot of the last month has been preparing for it. And in there was Thanksgiving. And in there I decided to buy an airplane (but that's another post).

One project that I'd had in the pipeline for a while but I just had't gotten all the pieces together was to create a temperature logging gadget for my vintage Beetle. I'm very curious as to how things warm up and cool down when it's first started, during driving and afterwards. So I'm going to install an Arduino data logger in the car, and instrument it with lots of temperature sensors so that I can download and graph data from it. There may be interesting things to learn there.

I've had an Arduino Mega for a couple of years but I've never really done anything with it (yet). I did buy a protoshield which is somethin that plugs into the Arduino board's sockets but allows you to solder things to connecto the Arduino withould making the connections permanent.

The Arduino Mega is on top, the protoshield is on the bottom.

You can sort of see the power rectified that's sticking up from the protoshield. It will drop the voltage from the car down to 8V. The Aduino likes to get somewhere in the range of 7 to 9 volts as input and then regulates it down to 5V internally. The documentation says that higher voltages aren't really recommended, which is wny I'm not driving the board directly with the 12V from the car (which can get as high as 14.5V or a bit higher when the engine is running fast.)

The Arduino itself is a microcontroller; it's a processor with inputs and outputs. Not very interesteing just that; it can blink lights, that's about it. Along with the protoshield, I bought two add-ons that will make it into a good data logging device. Once is a real-time clock:

That's a battery-run clock, like the type that's on a computer's motherboard, that tells the computer what date and time it is when it's powered on. The real-time clock allows the Arduino to put a time and date with each measurement it records, so that the sequence and spacing of the data is understood.

The other component I got is a micro-SD card reader:

I can put a micro-SD card in the jack and once that's wired to the Arduino, the Arduino can open files on the micro-SD and write data to them.

The first thing I'll measure is temperature. I bought a bunch of temperature sensors, but they're boring so I didn't take a photo.

The goal here is to be able to print out all kinds of information to see how my car is doing more precisely.