Category Archives: Diatribes and Rants

“WINGONEER Wireless Digital DC Voltmeter Ammeter Multimeter 2.4”

Purchased this thing via Amazon.

Received device yesterday, no user manual. Searched on line for “VAC8010F-80V” and found what looks to be a .pdf manual for this product. Got thing hooked up per the schematic in that manual. Battery is 12 Vdc, 2x20Ah SLA cells, on a solar PWM charger. Batteries are fully charged (14.4 Vdc) and in good shape. Disconnected batteries from charger.

Through a 12 V – 5 V dc-dc switching converter, connected 4 RTL-SDR-equipped Raspberry Pis and a DLink gigE Ethernet switch (total of about 1.5 A load at 12 Vdc). Device displays -1.6 A current draw, a little high from what my Fluke meter says at -1.5 A. Not bad!

The wireless function is kind of awesome – it just works. The range is at least good enough for having the sensors at the battery and the display head several meters separated, with some house walls in-between. The device uses the NRF24L01 chip from Nordic, so the transmission is in the 2.4 GHz band. I have multiple 2.4 GHz Wi-Fi units in the house, I can’t see how the link degrades, but it seems to be fine. It appears that one sensor unit can communicate to many display heads, or many sensor units can communicate to a single display head. Haven’t experimented with that.

The display is bright and very readable. The three buttons, from top to bottom, are “up”, “select/change”, and “down”. The function of some of the settings is a little hard to determine from the found manual, but I’ll survive. The temperature sensor is a ~100 cm long cable with temp sensor in a ring lug. I have it in-between the two batteries, and shows 28 C, which is close enough.

So the hardware is nice, but the software sucks. Seriously not good. I have had this running now for about 40 hours; the voltmeter function works fine, the current meter appears to accurately show positive current, and the temp sensor works fine, that’s about it. The running Ah and Wh meters just don’t do anything useful. I have 40Ah of 12 V SLA battery, I programmed in via the BAT function the 40.0 Ah size, I discharged the batteries a while until it reached 38.467 Ah. Then I applied a charge to the battery through the circuit, the battery capacity stayed at 38.467 Ah. The battery voltage has continued to increase to full charge, so that’s working. The BPC value is static at 96%. I tried to reprogram the BPC to 100%, but it won’t accept the value. I’ve tried changing the battery capacity to some other value to get it to reset the counters. It will not show negative current (power flowing into the battery from the solar charger). Not sure what to do about this. Probably will return it unless I get some answers soon. I guess I’ll have to wait until Sunday night (Monday in China).

China reports to be the first to arrive at the fusion “century” club

Chinese scientists have apparently created a sustained plasma temperature of over 50  million C for 102 seconds, making them the first initiates to the fusion century club, home of those nations who have hit 100 seconds.

In other news, the Chinese city of Hefei has lost all power and communications with the city have been silenced.

Ok, the second headline is probably from Faux Nooz. Really, if this is true, you scientists rock!  Gōngxi gōngxi!

The Mojave Phone Booth

I stumbled on this link when engaged in some otherwise pointless search on-line for something entirely different.

Like my desert-dog buddies, Bart R., Pete C., Greg M., and others, we all had our adventures wandering around the Mojave Desert as kids and then young and not-so-young adults. Some more than others.

The string (yes, there’s more than one) of phone booths in the Mojave was one of those fascinating, improbable, and curious marks of humanity and technology in an otherwise fairly natural and wild scene. The first time I stumbled across one was in a weekend adventure with Bart.

We’d been up in the Mountain Pass area, I think trying to suss out the Kokoweef mine/cavern mysteries, and decided to venture south into the Landfair Valley. We’d seen on the topo map an old railroad grade heading up a canyon from Ivanpah, and a bunch of old mines in the area, so it looked worthy of a visit.

Working our way up the path through the New York Mountains, passed intermittent signs of humans, some very abandoned, others fairly fresh. There were the occasional cattle, and sometimes a corral or stock tank. Even more rarely, there was what looked to be a cluster of buildings like a ranchhouse, but not much in the way of people.

Arriving at the north end of the Landfair Valley on the Goffs-Landfair-Ivanpah Road (aka Landfair Rd), it was just miles and miles of miles and miles of empty, serene desert. It was winter, so there were signs of some recent and rapidly vanishing snow over on Drum Peak, the high point at the west end of the New Yorks, and even some on the Mid Hills, to the southwest of Drum.

Anyway, we ambled along down the road until we discovered our improbable phone booth, either at the intersection of Old Government Rd or the intersection with Cedar Canyon Rd.  I’m sure that perhaps somewhere I have my own photo of it, but there are many photos of one of the booths and the surrounding desert available on the inter-webs!

Stopped and picked up the handset, and lo and behold, a dial tone. Pretty cool. We saw a sign adjacent cautioning about digging and damaging a cable underground, so it appeared that the phone may get its connection from the underground cable.

Once we got back to LA and to work the next week, I was determined to figure out how to call that phone booth and why it was there. Set me on a mission to find someone somewhere who knew. First stop was dialing “0”.

Nice operator answers, I tell her that I’d like to call this phone booth in the middle of the desert, in the Landfair Valley. I think she hands me over to a super-operator, or or maybe there’s a couple of handoffs, but ultimately I get to speak to a lady who seems to know how to contact the phone there. Sadly, I have no documentation now on this exploration from 40 years ago, but it was pretty awesome, as far as I can remember. First, that a snotty-nosed 20 year old kid could call the OPERATOR, and there was someone there who could navigate me through the arcane world of party lines and microwave links that somehow got to that one spot in the desert, and spend an hour doing it; second, that she then handed me over to someone at AT&T Long Lines (an engineer, I am pretty sure) who was excited to find a young person who was actually interested in their arcane but extremely vital universe of long-distance telephony and data communications; and finally that doing this didn’t trigger all sorts of alerts and alarms that I was interested in things like this. In today’s atmosphere, it seems like an invitation from the MIB or worse.

The story I got was that the booth was there because of tariff/regulatory rules. There was a long-distance underground cable buried there, along the old Government Road, and the rules required a public access for phone service no less than every 20 miles. This happened to be an empty spot in the desert where there were a few people living, there was a major road through here, so they put the booth there.

At this time, there wasn’t a direct-dial number for the booth, it was something like having to talk to a special operator and then asking for “Landfair 1”, or something like that. Awesome!


While I never did well in chemistry class, where they babbled about entropy regularly, I did come across something just now that made me think again about entropy.

According to the Information Philosopher (and many, many other sources, but this was the one that triggered this thought),

“…When information is stored in any structure, from galaxies to minds, two fundamental physical processes occur. First is a collapse of a quantum mechanical wave function. Second is a local decrease in the entropy corresponding to the increase in information. Entropy greater than that must be transferred away to satisfy the second law.”

So, logically, if a person (one who is capable of and does store new knowledge regularly) is decreasing their internal entropy by storing new information, then the entropy must be increasing around them. It’s like there’s a little entropy-transferring engine running in the person’s brain and as that information is encoded, the “waste” entropy is exhausted to the universe around the person. Thus, a smart person walking into a room and thinking must increase the external entropy. If there are others in the room, do they get dumber?

Can this be boiled down to “intelligent people make the dumb ones even dumber”?

Another thought – what happens in our state capitol when the Arizona Senate and House get together? Is the great roaring sound we hear that of the winds of entropy spiraling in on 1700 West Washington St?

We return you now to your previous program.