I often unintentionally come across interesting devices and, as with a crash scene, I can’t help looking further for more details, even though there’s little chance I will actually need to buy one. Recently, I saw a small new-product announcement in a print publication—yes, I do look through such old-fashioned information sources. The RG-9 solid-state rain-detector from Hydreon uses multiple beams of IR light to detect rainfall and signal when a user-selected threshold has been reached (Figure 1).
Figure 1 When water drops hit the outside surface of the lens of the RG-9 rain detector, some of the infrared beams escape; the sensor detects the change in returned beam intensity and determines the size of the rain drop that caused the change. Source: Hydreon
The unit has a relatively simple assembly and no moving parts, and is based on the same sensing principle used in automotive rain-sensing windshield wiper controls (Figure 2). Since, it’s sealed and has a transparent cover, it is fairly immune to dirt, dust, insects, and other possible sources of sensing interference.
Figure 2 The vendor notes that most of the complexity of the RG-11 is in the software and injection-molded optics, which results in a sophisticated product that is inexpensive to produce; it also has analog circuitry for the IR emitters, light sensors, interface I/O, and power circuitry. Source: Hydreon
I can’t comment on the performance of this patented device, but when looking at its specifications more closely, I noticed one interesting point. In addition to an indicator LED and a hefty open-collector output (80 V/500 mA), it also includes a 3.3 V RS-232 output. My first thought was: Haven’t seen many of those on new products lately. However, low-speed RS-232 can tolerate long wires and at low cost, which is useful in applications such as this one.
My second thought was a question: What can it interface, except legacy equipment? Sure, you can buy “RS-232 to whatever” converters, but that would add system cost and potential set-up hassles, maybe. Still, this device looks to be suitable for many situations where immediate and unattended knowledge of reaching a rainfall threshold is critical, such as farming and irrigation control.
While looking up this product on the Internet, I unexpectedly came across another website from the RG-9 parent company which was a truly oddball item, at least to me: a “fake” TV designed to discourage burglars checking things out from outside your home. The FakeTV is a small box available in three sizes and it does not present a picture but instead makes the same sort of flickering light as a TV screen (Figure 3). The idea is that when potential burglars see the light from this non-television simulator, they assume someone must be at home, so it would be better to stay away.
Figure 3 The FakeTV is just that: a small box which stimulates the time-varying light emitted by a TV screen, and which, after diffusion, is perceived as a real and larger TV screen. Source: FakeTV
The vendor makes it clear: FakeTV is not just a flickering light or flasher! And neither is it just a “random light source.” Their technical-explanation page notes that FakeTV uses dozen of high-interest LEDs in a package that includes a processor and diffuser lens. The pattern generated by these LEDs is more than simply plain-old random; it’s based on analysis of the light intensity and color variation of actual TV programs, which led to formulas and algorithms. These were then programmed into FakeTV’s microcontroller.
Is it effective? I have no idea. Nonetheless, it’s an interesting and intriguing application of modern technology to perhaps partially solve the ongoing problem of making your home look occupied when it’s not. Of course, you could argue that it also lets potential thieves know that you have a large TV.
Also related to TV, several years ago, I read about Mitch Altman, an engineer who was so sick of loud, always-on TVs in places like restaurants that he decided “then and there” to solve the problem, at least from his perspective. He quickly devised a single-button, keychain-pendant IR remote control which cycled through all the “turn off” codes used by the various TV vendors—and there are lots of them. It required anywhere from a few seconds to a little over a minute and to hit the right one for the TV under “attack.”
His gadget, dubbed TV-B-Gone, received a lot of publicity and was sold in tens of thousands in just a short period after it was announced (Figure 4). It’s still available from the inventor’s licensee—along with knock-offs, of course—and Adafruit even sells an authorized “high-power” kit version of the unit (Figure 5).
Figure 4 The TV-B-Gone keychain accessory has one button and is designed to do just one thing; that simplicity contributes to its utility and low cost. Source: TV-B-Gone
Figure 5 A larger, more powerful, but still compact version of the TV-B-Gone—made under license—is available from Adafruit as a kit. Source: Adafruit
Clever gadgets like these which solve a problem or sooth an irritation fascinate me, even if they are limited in appeal or success. These are often more than simply “better mousetraps” offering an improved way of doing something that’s already being done. Instead, they represent new solutions to the real problems, or to those which are personally perceived as such by their developers, or perhaps to issues which you may not consider problems at all. Maybe it’s a coincidence, but they all use electro-optical components—such as LEDs and sensors—which is certainly due to their low cost and ease of incorporation into a larger circuit.
Have you seen any such quirky “small” gadgets that intrigued you, even if you were not a potential user? Have you ever worked on such items “on your own” just to get it out of your system?
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