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June, 2013:

Dude, Where’s (the Rest of) My Thumb Drive?

Jun 21st, 2013
by Jeff Duntemann.
2 comments

Sony-XAV-601BT.jpg

My new knobless car stereo worked beautifully…except that it couldn’t keep time. The LCD clock display was erratic from the beginning. For the first day or two it was gaining five minutes per day. Then the whole thing reset to January 1 at midnight. I set it again to the current date and time. It ran fast for a couple more days. Then it reset itself again. Nothing was done to the car in that time frame, so it wasn’t that the battery was disconnected from the stereo.

It was just a lemon. So I invoked the 30-day warranty and took it back.

Yesterday I had them swap it out for a Sony XAV-601BT. I’m watching its clock (and everything else) but so far it’s glitch-free. Oh–and it has a volume control knob! It can do hands-free Bluetooth phone wrangling, and a lot of other stuff I haven’t figured out yet. But in addition to all that, it has a USB port on the front panel. That means I can plug a thumb drive right into the stereo itself, and not into a wire dangling off the back of it.

Skin and Fit.jpg

Of course, having bent more than one thumb drive by careless use, I wanted to be sure that a casual hand-wave wouldn’t destroy a drive with every damned MP3 I own on it. So I bought me a thumb drive unlike any other: The 16GB SanDisk Cruzer Fit. Once you plug it into something, the part that sticks out isn’t quite 1/4″ long.

Dude! Where’s the rest of my thumb drive? But no, that’s all there is. It’s just a bump on the stereo front panel.

The stereo is still on probation, of course, but I’m thinking this one is a keeper. More as it (hopefully doesn’t) happen.

Odd Lots

Jun 17th, 2013
by Jeff Duntemann.
10 comments

Measuring Raspberry Pi USB Power Draw

Jun 13th, 2013
by Jeff Duntemann.
1 comment

Smartronix USB Meter.jpg

Most of the problems that turn up while configuring Raspberry Pi systems cook down to inadequate power. The infamous stuttering keyboard problem vanished immediately here when I put the RPi on a stiffer 5V supply. When I bought a second RPi for a programming system, I incorporated a powered hub capable of sourcing 500 ma from each port, and in doing so strangled the power problem in its crib.

Problem solved, but I still wondered: How much juice do these things actually need? How stiff is the 5V supply? I’m a bench tech, and not being able to do actual measurements made me nuts. So I sniffed around a bought a test instrument for measuring voltage and current at a USB port under load. It’s the Smartronix USB Power Monitor, model ST034TT05-01-001. I bought it from CyberGuys; $49.95.

It works like any current meter: You connect it between a USB port and a USB device. It simultaneously measures the voltage on the port and the current through the device. There’s a full-size Type A jack on the right side of the box for connecting the load, and a full-size AB cable plugging into a B jack on the left side of the box, which plugs into a Type A port.

Works like a charm. I did the measurements below in about ten minutes:

Raspberry Pi board running Raspbian, w/o Wi-Fi 50-73 ma
Dell 0C8639 wired USB mouse 5-17 ma
Dell SK8135 wired USB keyboard 53-56 ma
AirLink AWLL5088 Wireless N Ultra Mini USB Wi-Fi 32-80 ma
SanDisk Cruzer Mini thumb drive, 256 MB 27-30 ma
SanDisk Cruzer Micro Skin thumb drive, 256 MB 75-89 ma
San Disk Cruzer Mini thumb drive, 512 MB 7-11 ma
KingMax Super Stick thumb drive, 512 MB 35-62 ma
SanDisk Cruzer Mini 1 GB thumb drive, 1 GB 5-11 ma
SanDisk Cruzer Micro Skin thumb drive, 4 GB 75-91 ma
SanDisk Cruzer Micro Skin thumb drive, 8 GB 43-70 ma

In the readings above, the two numbers are the range across which I saw current run. In most cases, the first number is when the device is idle, the second is when it’s busy. All measurements were taken from the same USB port, one of the four ports on the Rosewill powered hub. All devices tested are USB 2.0, because the meter itself is not listed as capable of testing USB 3 devices.

I have several of most of the thumb drives, and identical models were almost alike in their power behavior. This made me wonder how the Cruzer Minis managed to use so little power while doing the same task that all the other drives did. In this case, the task was copying a 109 MB file (the Lazarus 1.0.6 installer) from the PC to the thumb drive. One would think that smaller drives would draw less current, but not so.

Probably the biggest eyebrow-raiser was how rubbery the 5V USB rail is on my quadcore. An 8GB Cruzer Micro Skin thumb drive pulled the port down from 4.99 v to 4.91 v while drawing 90 ma. The same drive pulled the Rosewill hub supply down by only .02 v , from 5.17 v to 5.15 v while drawing 70 ma. (Current draw in thumb drives is not the same on the RPi as it is on Windows.)

My only gripe about the meter is that “peak” mode displays the highest values for voltage and current, when voltage and current generally move in opposite directions as load increases. So a downward movement in voltage isn’t registered in peak mode.

Other than that, it works as described and answered a whole lot of questions about what sorts of things I can reasonably expect to connect to a Raspberry Pi’s built-in USB ports. Actually, I now recommend using the powered hub for everything, given the RPi’s touchiness about power. It makes the RPi system bulkier and snakier, but a whale of a lot more reliable.

And as for the Smartronix USB power meter, let’s say solidly (if not quite highly) recommended.

The Black Forest Fire From a Safe Distance

Jun 11th, 2013
by Jeff Duntemann.
2 comments

Black Forest Fire June 11 2013-1.jpg

I hope.

Actually, it’s about 17 miles NNE of here. I drove down Broadmoor Bluffs to where I had a good NE horizon to take the shot. The location is about 200 feet higher than downtown Colorado Springs, so it’s as good a vantage point as I’m likely to get.

We’re just looking over our shoulders a lot today. I don’t think we’re going to stop any time soon.

Something’s Burning…Again

Jun 11th, 2013
by Jeff Duntemann.
No comments yet

Noonish today, Carol asked me to go out on the porch and sniff. There was a haze in the air that we don’t generally see, and the faint whiff of fire. I knew that there were a couple of fires over a hundred miles SW of us, and didn’t give it a lot of thought. I had a writers group meeting at 1 PM up at the Pikes Perk coffee shop at Academy and Vickers. We wrapped up a little before 3, and when we got out into the parking lot, Cynthia Felice began gesturing wildly to the northeast. I was already in the car, but I jumped out and looked where she was pointing.

Immense plume of black and gray smoke. I watched for the motion of the billows to get a sense for its distance. My guess was 6-7 miles. Once I got home it was all over the local news, and we learned that it started in the Black Forest area northeast of Colorado Springs. Measured distance from Pikes Perk to the fire is about eight miles, so I was close. From our house on the other side of the city (we’re less than a mile from the NORAD entrance, if you know where that is) it’s about 18 miles to the fire. I should have snapped a picture on my phone, but I wanted to get my butt home ASAP.

And there’s another one. A new fire broke out down near the Royal Gorge to the west of Canon City at about the same time. That one is even farther away; I measure about 30-35 miles from here. Still, we’re seeing the smoke from here, and the air smells a lot more like fire.

The Black Forest fire is blowing toward the northeast, directly away from us and away from more populated areas in Colorado Springs. However, several houses have already burned, and it doesn’t sound like there’s been any progress yet in controlling the fire.

I’m putting the dog kennels in the 4Runner. I’m watching things on TV. We’re in no immediate danger, but cripes! Up in Black Forest homes were burning half an hour after the fire was reported. When there’s a 30 MPH wind, these things happen fast.

I’ll report here and on Facebook from time to time. Check Facebook first.

Odd Lots

Jun 9th, 2013
by Jeff Duntemann.
6 comments

Man, But I Miss Knobs

Jun 7th, 2013
by Jeff Duntemann.
4 comments

avh-x2500bt_hero_large.jpgThe six-disc changer in my 4Runner’s console stereo dropped dead late last summer, after serving me well for eleven years. Considering the mechanical nightmare the damned thing was internally, I’m a little surprised it lasted as long as it did. So for about ten months now, I’ve been reduced to listening to the radio, in a town where radio is not a priority. (Irony, however, is a Colorado Springs delicacy: With just about every other town and county but Denver voting to ban legal marijuana, the home of Focus on the Family looks like it will soon be the highest city in the state.)

I haven’t listened to pop radio in the car for maybe 25 years, since I started recording mix tapes off vinyl. I expected to develop (however unintentionally) an appetite for recent pop music. Hey, it worked with Madonna in 1986. Not this time. I found one band worth investigating further (Owl City) and bought four, count em, four MP3s. A couple of Owl City tracks, Kelly Clarkson’s “Catch My Breath,” and Two Door Cinema Club’s moody song “Sun,” which I bought because it contains the word “drumlins.” Just that, based on ten months of mostly cringing and reaching for the volume knob.

Now I can’t even do that.

After punting for far too long, I went down to Car Toys earlier today and had them install one of these. It had a Bluetooth phone feature I wanted, since I don’t like manhandling a phone in the car. It plays MP3s from a thumb drive, and every MP3 I have that’s worth hearing will fit on a thumb drive. (Not a big one, either.) It looks for all the world like a smartphone held sideways, complete with the little four-square menu button. All it lacks is a volume control knob. It has a mute button, which will come in handy, just like it does when The Weather Channel plays that excruciating commercial about the poor woman who’s been falling on her kitchen floor and failing to get up since before they tore down the Berlin Wall. It has firmware to update, God help us, and…cripes, I wasn’t ready for this…a remote.

At the risk of sounding like an MP3 on autorepeat, well, all it lacks is a volume control knob.

I’ll get used to it. (I got used to Madonna in 1986, after all.) Mostly what I want out of it is hands-free phone calls and MP3 playback. I know why it doesn’t have a knob: Knobs take room on the panel that you could otherwise fill with icons. And a knob would add another 85.67 cents to the UMC. Besides, knobs are just so 1952.

Just like me.