I've been looking for an inexpensive and compact oscilloscope to round out my test equipment collection. I'd seen some of the ones that are PC based, and wasn't really interested in something tethered to a computer - I don't have one on my electronics workbench. After a bit, I found the DSO Nano, an open source Digital Storage Oscilloscope based on the ARM CortexTM-M3 32 bit processor. It's not especially powerful or capable, but does the basics and is quite inexpensive: $89 delivered.

It has a 320x240 pixel color display, a micro SD card for waveform storage, is powered by a lithium polymer battery, and is rechargeable via USB cable. It has a built in, basic signal generator, and comes with a set of probes. It fits neatly in the palm or your hand, and also comes with a simple stand that makes it very comfortable on the bench top.

As I mentioned, the device is open source, meaning that its firmware is available and hackable, and it has well and truly been hacked. Nobody who has used one of these little gems for long sticks with the standard frmware. There is a free replacement written by someone calling himself benf, that is a great improvement over the original, adding greater sensitivity and accuracy, a more coherent set of menus, better performance, and many new modes operation.

This morning I upgraded my firmware to benf 3.62. While it took me a while to figure out all the pieces I would need to do this and gather them from the far corners of the net, once I got it all together, the upgrade was simple, painless, and quick. I have uploaded all the files necessary to upgrade any model of DSO Nano to benf 3.62 in a single zip file in the Documents section of my own profile.

I'm waiting on an Elenco basic signal generator, which should be here in the next day or so. When it arrives, I'll play more with the scope, and post some pictures, and mayne even video here.

You wouldn't pick one of these up hoping for Tek or B&K capabilities, but if you just need the basics, the DSO Nano looks like a great deal.

More later.

My undergraduate degree is in Electrical Engineering, but I really can't remember much of it. Heck, I graduated in 1980 and I really can't remember much of anything that far back. I guess I learned lots of theory: power systems, circuits, electromagnetic fields, solid state stuff - you name it.

Not too upset that most of it is hazy in my mind.

We also learned quite a bit about test equipment in our labs: oscilliscopes, signal generators, frequency counters, and a bunch of other doodads I can't remember.

That stuff I wish I remember better!

I've been playing with a variety of electronics stuff, mostly related to the N8VEM project and the Arduino, both very cool things to do if you like being close to computer hardware and tinkering. Follow the links if you want to know more about either project.

Both of these projects require me to breadboard, solder, and test. They provide a great excuse to buy more stuff: a digital temperature controlled soldering station, a multimeter, a logic probe, a circuit board vise, a variety of minuiature hand tools, and most lately, a mini-osclloscope. I've also collected a batch of electronics parts: resistors, capacitors, switches, relays, LEDs, and a bunch more. I've even put together a small lab. Great fun!

I'll follow up this post with others containing information about the equipment I've amassed over the last few months, hoping others that would like to get into electronics might want similar, relatively inexpensive things.

The back bedroom is free again, and I've reinstalled all the stuff that was most important: the 3B2/600, Quadra 800, and P1. Networking is back in operation with a small switch in residence, and this time I've elected to keep only one monitor attached to the Quadra. All access to the other systems is via telnet. If I need to in the future, I can always hook up the KVM switch, but this time I'm really going to try to keep down the level of clutter.

That leaves a lot of extra stuff laying around: cables, disk drives, cd-roms, floppy drives, modems, terminals and old computers. I've got to do something with them. As I mentioned in a previous post, I'll be giving away some computers, and I think I have a bunch of miscellany to give away or scrap.

I'll be posting on the rescue list or craigslist.

Well, it's a little late for Spring, but clean I will. It's time to get rid of some of the clutter.

Up for grabs are three (mostly) working Kaypro 4's, each with dual 5.25" floppy drives and software. I will give these away for the price of packing and mailing.

Also free is a Mac Workgroup Server. I think it's a G3 or maybe a G4. I 'll look and get a full configuration. As far as I know it is fully functional.

I will also be junking a bunch of cables of various kinds, and lots of other flotsam and jetsam.

Those interested should get in touch. Otherwise I will advertise them on the rescue list. If there are no takers, I will likely scrap them. I imagine the Kaypros will go pretty quickly.

I keep most of my collection of old machines and operating systems running 24x7, and they live in my spare bedroom, which over time gets quite cluttered with computers, parts, documentation, ancient books, floppy disks, and other flotsam and jetsam. I'm afraid it's mostly because I'm a pack rat and something of a pig. Still it works for me, mostly.

The problems start when we have guests, thankfully not very often.

My parents are moving from CA to VA, and have bought a house just down the road from us and will be staying with us in said back bedroom for about a week. My lab and network will need to be dismantled and stored while they are staying with us.

It's a sad day. I've got to find a place to store my 3B2/600-G, my Mac Quadra running A/UX, and my P1 running UnixWare 2.01, plus a lot of spare parts and miscellaneous stuff.

On the other hand, it will certainly give me the opportunity to clean things up, get rid of some junk, and store more valuable things more sanely.

Maybe I will even learn a lesson, though if history serves, I doubt it.

The Wyvern Network will be down sometime next week till approximately the first week in June. Sorry!

On a hunch, I brought the PockeTerm in to work this morning and at lunch I got a chance to plug it into my LCD display here.

It worked!

Looks like the problem was compatibility with the monitors I tried. The keyboard did not work, but I bet there is some dumb compatibility problem there, too. When I get home, I'll try a variety of the keyboards I've got lying around. I bet I can get something to work.

Tonight I think I'll be using the terminal to talk to one of my Unix boxes!

Huzzah!

Oh, never mind! I pulled out another keyboard, this one an old Dell here at the office, and it worked fine. I guess the PockeTerm hardware is a little choosey about what it works with.

Now I know I'll be playing with this thing on real hardware tonight!

I managed to resolder the caps last night and then get the rest finished up according to the instructions. Initial power test was fine: on/off switch worked, and the LED lit when power was applied.

I then mounted the ICs in their sockets and plugged the thing into a LCD monitor and a USB keyboard with USB to PS2 converter.

Unfortunately, there was no signal to the display. Power at the 5v voltage regulator is fine.

So... tonight I'll try some different displays and if that doesn't work, I'll start checking the board for potential bad solder joints. If that doesn't lead anywhere, I'll go begging for help on the Briel site.

I'll post a picture or three now.

I spent about an hour last night identifying and inventorying all the components for the PockeTerm and beginning the assembly.

As I grow older, it gets harder and harder to make out the codes on very small resistors and capacitors. I've got one of those magnifiers that you wear like a huge pair of glasses to help. Luckily, mine came with three magnifications, so I was able to see the tiny writing on the tiny caps. I would never have been able to do it without them.

So, after getting it all straightened out, I fired up the soldering station and began. The resistors, switches, IC sockets, and the crystal went in fine. Capacitors were no problem till I got to the polarized tantalum caps, and soldered two of them in backwards. Oops!

So at that point I figured it was time to quit for the night. Tonight I'll desolder them and turn them around if I can do so without destroying them. I figure the PockeTerm will be completed and maybe even tested tonight. If I destroy the caps, I'll have to go out to the electronics parts store and buy some new ones. Guess it would be this weekend.

I'll also take some pictures!

A little company called Briel Computers makes a Propeller microcontroller based serial terminal call PockeTerm.

This is a tiny thing that draws almost no power, provides full VT100 emulation, and uses a standard VGA monitor and PS/2 keyboard for I/O. It connects via standard DB9 serial (DTE or DCE).

Mine came in the mail as a kit tonight. I inventoried all the parts and will likely solder it all up tomorrow. Pictures tomorrow.

This is the beginning of the N8VEM project!

While looking around at the N8VEM project, I also happened on the Arduino. The Arduino has to be one of the coolest things I've ever run across.

Years ago I played, very briefly, with a Paralax Basic Stamp. This is a micro controller that can be used to build fun circuits, and is programmed in Basic.

The Arduino is its big brother, and amazingly, all the hardware and software are Open Source. Well, not the individual chips, but all the boards, the development environment, the documentation, and tons of interesting circuits, machines and projects.

See much more at the Arduino Home Page.

I got involved  because it's an easy way to get into reading schematics, examining circuit boards, and soldering electronics together. Sean and I have already built some pretty cool stuff with Arduino, including a couple of piggy-back boards, called Shields inthe Arduino language, some basic LED circuits (blinking, fading, controlling), a 20x4 LCD panel board, and a doodad that is somewhat like a Theremin. Our first real project will be to design and build an infrared proximity alarm.

I'll upload some pictures as soon as I get a chance.