Author: Chas

I don't know why I blog, because? I have no agenda, just love electronics and want to share. I love to follow other experimenters/hardware hackers just to see what other people are working on. Shoot me a message if you blog.

Workshop check…

We don’t have “workbenches” any more right? That got boring? Mine is a little pathetic right now. We moved from San Diego out of a tiny 900sq ft apartment with three of us, to this house. So with all this new space I’ve planned on a late May  visit to my house in South Dakota which still has my workbench and much of my test equipment. I’ll post a new photo in a few months, you still won’t see much test equipment, I can’t stand being crowded with test equipment; I like plenty of project/arm room. The bench I’m bringing back was a lucky score; I bought it off an electronics factory (that got out-sourced to China)… Not to mention boxes and boxes and boxes of books. I love looking at workshop photos, please comment with yours!

I think we're suppose to call these "Hacker Spaces" now right?
I think we’re suppose to call these “Hacker Spaces” now right?

Homebrew TDR

One of my favorite vloggers is w2aew. A recent posting has got me thinking TDR…. supersized. I was planning on playing around with a compass/barometic pressure sensor with the Raspberry Pi but that may wait.. (or perhaps I should pick up a cheapo model A). I don’t use a lot of coax these days but a TDR for CAT5 might be handy. If you watch this video I imagine you can fill in the blanks and see how I believe with an A2D converter and a stable parts (read: frequency) you could have yourself a real nice basic TDR.

5 EA 74AC14 ‘s are $3 and some change right now on eBay. I had some eBay bucks ready to expire so I ended up getting mine for “free”.

I tried the circuit out with a 74LS14 which is obviously turtle powered compared to the ‘AC14.. I could still determine the approximate length of my CAT5 even with the circuit on a breadboard. If you make an attempt the value’s used in the video will not work. If you need a little help ( http://www.electronics-tutorials.ws/waveforms/generators.html ) If you’re going the same route don’t forget CAT5e’s impedance is roughly 100ohms so make the necessary changes in your parallel resistors.

Barometric pressure

I was reading an elektor article and ran across the “BaroStick” Article. ( http://www.elektor.com/magazines/2013/may/barostick.2457910.lynkx ) — I have a Raspberry Pi on my birthday wishlist which I’m fairly certain I provided adequate hinting that it was the “to buy” present. It was the CanaKit that comes with all the typical goodies. I’ve been a long time user of the Microchip PIC chips and I’ll continue using them in designed but I felt that I need to break out of my VB.NET and assembler shell. Python actually looks worthy enough to tie up some neural connections; in the process of reading Simon Monk’s “Programming The Raspberry Pi” . The very same elektor also has an interesting article on BASIC to Python (May 2013 pg 26). Those of you who know me know I’m not a huge fan of C. You can keep your C and just chalk me up to a lost cause if you desire.. C is just not for me. I’ve done all the handy C introductions and hello worlds and manipulated it where I HAD to…but I’ll stick to assembler and BASIC thank you. I’ve also dabbled in plenty of PERL and COBAL and was formally educated with Pascal. While we’re talking about ridiculous aversions; I also have a huge, totally un-based, beef with Arduino… Like Apple vs. Microsoft beef. So you won’t catch me with an Uno unless I needed it to test the dielectric properties of FR4.

Okay stay with me… almost there.

Because of that distaste for all things Arduino; I never visit Adafruit ( http://adafruit.com ) unless I want to be reminded how perfectly lovely female EE’s can be. That being said I had purchased a BMP085 from my favorite website to visit when I’m feeling project-idea-block… Sparkfun last March. ( breakout board found at: https://www.sparkfun.com/products/11282 )  I love their breakout boards.. a second stop would be http://www.tindie if you’ve been under a rock and find yourself trying to consider some “fun” projects to take on. With this BMP085 breakout board I have on my “to-do” list to build a altimeter for hiking. Is it heavier, yep.. going to use more power? Yep… look as attractive as that Suunto $500 watch? No where near.. but it’ll come off my bench. Turns out in my web expeditions to save myself some coding out dearest Limor has taken all of the work out of it.. ( http://learn.adafruit.com/using-the-bmp085-with-raspberry-pi/overview )  with a small fix: ( http://forums.adafruit.com/viewtopic.php?f=19&t=38293#p191390 ). Will I be visit adafruit more often? Maybe so…

I’ll report back on this project once my birthday rolls around.

US Forest Service Website Down.. maybe they ran out of money?

Forest Service website down over missing file or missing budget?
Forest Service website down over missing file or missing budget?

The Us Forest Service website was down this morning. Perhaps a bill went unpaid, or someone accidentally deleted index.html? I guess we’ll see if they come out with an explaination or not. For now it looks like I’m SOL on road conditions in the Northern Cascades unless I want to drive up and talk to the ranger or drive a few more miles and go look for myself.

8088 PC Computer

Under the hood of a 8088 XT PC desktop computer
Under the hood of a 8088 XT PC desktop computer

A friend of mine was moving and no longer had room for this treasure. I generally only like to collect older computers in particular I’m fond of S-100 equipment or CDP1802 based items. This was too much to pass up though. On the top you’ll see the 5-1/4″ floppy to the left, followed by the (I believe to be) 20MB MFM hard drive which is tiny (in physical size, typical for memory capacity) for it’s day… the DIP memory to the right, I’m fairly certain by memory part numbers I’m looking at 640kB of memory. .. then in the 8 bit ISA slots on the bottom you have the MFM hard drive controller card on the left, then the floppy… a serial port adapter (25 Pin D-SUB) and finally 9 pin monochrome video adapter with a built in parallel port. Unfortunately the monitor he gave me has a 15 pin D-SUB which I thought they started at VGA but perhaps it’s an EGA monitor–it’s poorly marked. At least it came with the 5 pin DIN keyboard. As soon as a built an adapter for the video I’ll give it a chance at a boot-up. I’m considering a trip down to Alphatronics this weekend to see if they have an 8087 co-processor since they weren’t typically installed and that seems to be the only stuff Alphatronics has any more (old chips everyone’s long moved past, try getting an OP Amp there released in the last 5 years). After my visit there I’ll hit up  RE-PC in Tukwila; perhaps they will have some spare cards and extra memory if I’m really lucky. Another score for my personal museum collection.

3 Axis CNC Controller TB6560

So I bought this controller on eBay a few weeks ago. I honestly haven’t done anything with it as I’ve been a little focused on the mechanicals. It seems a little in the cheesy side as the labeling an keypad aren’t complete secure. I’ll provide an update once I power it up. I put the USB to parallel port adapter near it for a size reference. I guess we will see if this was a $130 mistake?

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