Radex Lupin: When the Light Can Count

    Good evening everyone!

    In fact, I am a hopeless owl. In those blessed times, when you don’t have to get up anywhere and you can choose your own waking hours, I rarely go to bed before 7 in the morning and even less often get up before dinner. And I live in those latitudes where it is cold for three months, the other nine are very cold, and the sun peeks out from the horizon sometimes only so that they do not forget about it. And I’m a programmer and ... In general, artificial lighting is my sacred cow, which allows me to spit on all kinds of circadian rhythms. So when Dadget offered me a Radex Lupin light meter for review, I could not help but get this toy in my tenacious paws and walk with it through all the lamps in the house. Do you want to look at what came out of it all? Then be sure to look under the cat: today underneath is an overview of the light meter itself, a test of a bunch of light bulbs, some tips and one little surprise for geek porn lovers. And a whole bunch of photos, yes.

    Why is it necessary at all?

    Good question, by the way. The guys who are engaged in biology and other natural sciences tell us that light to some extent affects our nervous system, vision, ability to concentrate and a bunch of other interesting things that determine our condition. Even simpler - improper lighting for some time can lead a person to a state of limp and unable to concentrate on at least something decent vegetable and vice versa - high-quality light contributes to excellent health and excellent health.

    And what kind of light is the best?

    Natural, what else. But if the sun has already gone beyond the horizon, and you still do not want to go beyond the horizon, you will have to turn on the light bulb. And with her everything is already much more complicated. And in order to choose the best one, one has to remember what parameters the luminous flux has.

    Good old Wiki tells us that this is the ratio of the power of light emitted by a surface to the area of ​​its projection onto a plane perpendicular to the axis of observation . This case is measured in candelas per square meter and is even considered one of the main SI units. True, as a rule, you and I do not need it

    It depends on her whether you will break your favorite eyes about your equally favorite book or not. The same Wiki hints that illumination is a luminous quantity equal to the ratio of the luminous flux incident on a small area of ​​the surface to its area . Measured in lux, and one lux equals one lumen per square meter. To understand how many of these suites you need for comfortable work, there is such a tablet.

    By the way, at least 50 lux is recommended for reading from real paper. If you follow these recommendations, there is a rather big chance that your eyes will last you several decades longer. In my opinion, it’s quite a good reason to screw in extra paw

    Ripple factor
    While we are under natural light, this does not bother us. The only problem is that the current that almost all artificial light sources feed on is alternating. Yes Yes? Do you have a permanent one? Happy for you. But for myself - not really. Because the alternating current, oddly enough, is actually alternating and all these ripples are somehow visible to our eye. And despite the fact that we do not see the blinks themselves (something else was missing), they have a slight effect on us. Doctors do not get tired of telling us that a high pulsation rate can result in fatigue, fatigue, poor sleep, poor performance and other unpleasant contraptions that we would like to avoid. Therefore, the less your light bulb flickers, the better. True, in our country, in the Russian Federation, it is believed that all this relates only to pulsations at frequencies up to 300 Hz. Like, everything above

    Color rendering index
    The thing is not so important for you and me, but without it it’s still nowhere, especially if you are working with a camera. Roughly speaking, this index shows the degree to which the color of a certain body is visible in a particular type of lighting. So, if in the photo, your favorite red T-shirt looks slightly green, that’s just it

    Did you figure it out with the parameters? Now, let's try to measure something. First, however, you have to decide what. To determine the brightness we need a brightness meter , for illumination - a light meter , and to determine the ripple factor - a pulse meter . To hang around with a box of three gadgets is somehow uncomfortable ... Is there anything that will allow us to measure everything at once? Yeah! There is!

    What is there?

    Dadget’s Radex Lupin light meter-pulser-bright meter allows you to measure the first, second, and third with high accuracy. And he perfectly fits into the hand and is convenient to carry with him. And he knows how to determine the frequency of ripples. And he with a flick of the wrist, can turn into a portable scum ..., however, more on that later. In the meantime, let's finally look at him

    Sweet box. To be honest, I expected her to be at least twice as healthy. Have you seen enough of an ad? Then we take out the box from the wrapper.

    Modestly. For some reason, it reminds me of boxes from a Swiss watch ... Maybe the accuracy of this light meter will be the same? We’ll find out now! We are opening!

    Cool, charging is always not enough for me, somewhere they constantly fly apart. As for the light meter itself, it’s even smaller than I thought even after I saw the box. You can put this in your jeans pocket, nothing will be done with it. I wonder how it turns on?

    Yeah, just click on any of the three buttons, as he starts to show something. Okay, let's put it aside for a sweet and see what else there is

    Charging. The usual 220 AC → 5 DC adapter, judging by the inscriptions on it, is even an entire ampere. Nothing unusual, but nice, because for the sake of cheaper even some phones come with just one cord.

    Well there he is. Solid, thick USB → MicroUSB cable. True, a little short, so you can’t get far from charging. However, the cable has another purpose, about which a little later

    Wow, lace! The memories of the distant 2005 immediately climb into my head, when I finally got the first mobile phone and I immediately hung it on my neck. However, a light meter on a rope is actually convenient, because carrying it between measurements in your hand, in which there is also some kind of a sheet with the results ... in general, is a nice thing

    . Instructions. For several years, this is perhaps the first that I will read before I break the light meter. Why? Well, firstly, she is with pictures. And secondly - it says how to correctly measure the light, brightness and ripple. Want to read too? Keep

    Uh ... another instruction? No, of course I like to read, but I like the previous one more. She is prettier. So put this thing aside and finally get down to the light meter itself.

    To begin with, technical specifications:

    Hmm, if you believe them, it turns out that Lupin is never a toy, but quite a decent suite (and other) meter. At least, without creeping out of the atmosphere, it will be difficult to get to the upper limits (illumination outside the atmosphere is approximately 135,000 lux), and a lithium battery is going to save us from having to look for batteries around the house. I wait - I can’t wait when lithium starts to be put in cheap wireless mice.

    And again - the device is insanely small. And he also has a pretty nice surface with a soft-touch coating. That is, it is convenient and pleasant to hold in your hands. Management here is simple to disgrace: on the front panel there are only three buttons. The first includes a light meter, the second - a bright meter, and the third (and what remains for it) - a pulse meter. And if you do not press the buttons for as long as 70 seconds, the device will turn off and it’s not very convenient anymore, you never know what I need to measure there, especially since recharging the battery is not so difficult, even if I forgot to turn off the device. Okay, let's leave this thing to the conscience of the developer and look at the display

    We have here OLED, inverse, and even graphic. Just a holiday, especially after the same type wh1602 - similar and disgustingly readable displays. In the upper bar we have an indicator of the current mode (E - Illuminance, L - Brightness, P - Ripple) and a battery indicator. Why does he have a diagonal strip at once is not very clear, but apparently, the device is charged. At the bottom of the screen, the measurement results with units of measure, as well as the X1000 indicator, hinting that the result should be multiplied by this very thousand, because it did not fit into the screen in a different way. By the way, to get the same picture as mine, hold down the two extreme keys - look not at the firmware number and release date. Ascetic, functional, nothing more.

    Using the device is simple. We press the key that is responsible for the mode, we direct the head of the light meter to the light source where you want to measure the illumination and - we get the result. The head itself is rotary, you can twist it anywhere, but it is fixed in three positions: “up”, “on us” and “from us”. By the way, if there is not enough illumination to get reliable data, an additional icon will appear in the upper bar that looks suspiciously like the letter “O”. Figured out? Let's measure something then? For example, the illumination of my own table:

    Almost kilolux! In general, it seems to be true, a 20W fluorescent light bulb, and even the sun that has not gone beyond the horizon ... In general, it should be light for me to work. And look at the ripples?

    Not so good anymore. According to SNiP, the ripple coefficient in a room with computers should not exceed 5%. I have it right on the upper border ... Can I change a bulb?

    Well, the 10-watt LED from Navigator. The same kilolux, but there was clearly less ripple. I wonder if I will feel better?

    And what about the upper light in the bedroom?

    Oh you! Hello, Chinese non-capacitor. Here they definitely need to be exchanged for something decent as soon as possible.

    And on the street?

    I said that the sun in Siberia is a decorative thing. But it does not pulsate :-)

    Oh! And this is my homemade LED lamp. Judging by the testimony, the orange should be satisfied. However, he is actually growing quite well.

    The night, under it I usually read. More than 50 lux means you can!

    Well, poked, looked, wrote in a notebook that the bulbs need to be changed - this is not so interesting. Let's try to get a little more data? We take our light meter and connect it to the laptop via USB.

    Great, Lupin realized what they wanted from him and, just in case, started charging. But Windows didn’t pay much attention to it ... Strange, for some reason I was sure that he would define himself as a flash drive and offer to install something. Then you have to take a walk to the website of the Dadget and download this program

    here. That's better. Further, further, further, ready ... and what else is this ?!

    FTDI? That is, the light meter does not build itself a HID, but just pretends to be a COM port? Looks like I just got an interesting little idea ... Okay, let it wait a while. In the meantime, we

    ’re launching the program Wow, krakozyabry! I haven’t seen such a long time) Okay, we’ll be updated, since they’re offering

    Now, now everything is in order. We start measurement

    Visually. I wonder what standards the color stripe meets?

    This they call the professional regime. Well, in general, the way it is, at least here you can look at a couple of interesting graphs. By the way, after the word "Oscillogram" my idea became stronger in the desire to be realized. Do not forget. Let's see at what frequency my desk lamp pulsates?

    Oh, what a good lamp! Bursts at 50 and 100 Hz are clearly visible, but they are clearly not enough for the program to consider this a ripple.

    Chinese flashlight with PWM brightness. Such a chandelier should not be hung. By the way, do you remember my homemade watches on past pics? Let's poke them?

    Well, yes, dynamic indication on shift registers is nothing unusual.
    By the way, Dadget actively recommends using Lupin as a tool for testing monitors and other screens. And I have just at hand either a monitor or a screen. Let's poke it too?

    Good monitor. Judging by the spectral analysis, the PWM frequency is somewhere in the kilohertz region, while we are not interested in anything above 300 Hz. You can consider the picture almost static.

    The phone is also doing well, the light meter here does not see any bursts at all. It seems that the night gatherings in Telegram do little to hurt my eyes. I wonder what will happen if ...

    True, the picture is familiar? It’s me who transferred the flashlight to strobe mode. Well, what I wanted, I got it. True, now I still want to test one of my theory ... Let's open the device? To do this, simply unscrew the three bolts on the back cover and calmly remove it. And at the same time, we take off our hat to the developer of the gadget, who guessed not to stuff the case with latches.

    So far, I like everything: the board looks neat, the photosensor is removed, and the elements are even well soldered. True, I expected the battery to be square, not round. We remove the case and turn the board over

    It seems that the entire light meter is built on a single 32-bit ARM - a microcontroller and a bunch of strapping. By the way, where's the FTDI chip? Now it remains only to carefully look at the contacts for the photosensor and poke them with a voltmeter.

    It looks like the pinout looks exactly like that. Let’s put some meander on the data leg?

    They filed a meander - received a meander, or rather, what is trying to be it. Now pretend to be an antenna

    Yeah, he eats a tip at 50 Hz. All this means that voltage is applied to the input from the photosensor (and what did you want from the photodiode?), And the ARM controller takes care of everything else. That is, if you remove the data leg somewhere outside the case, we can get a very tolerably working oscilloscope. Cool, right? And since the data goes on the COM port, nothing prevents us from clinging to it and looking at what goes on there.

    So the data leg is grounded.

    And so, it’s the same, but drawn to power, which, by the way, is 5.00 volts throughout the whole scheme. It remains only to understand what is contained in these four bytes of data (and it seems to me that the values ​​of the ADC are there and the checksum), write a small receiver of these data, which will not recount them into suites and the pocket oscilloscope is ready! Perhaps I will do this when there is time. In the meantime, collect the device back and tighten the screws.

    And what?

    It turns out that according to all tests, Radex Lupin is an excellent suite, bright and, most importantly, a heart rate monitor that will allow you to choose high-quality lighting in the room, determine the degree of decency of the monitor, choose a really good light from a good dozen and extend your life, so necessary eyes. And if your hands grow from the right place - you can use Lupin as an entry-level oscilloscope and much more. By the way, you can use it in such a way that you can do it quite inexpensively - the retail price of a light meter will be only 4900 rubles, which is much less than that of any professional light meter included in the state registry.

    Oh yes. You can buy this device here: Sincerely your reference

    , turning a light meter into an oscilloscope and, at the same time, into a coffee maker, GrakovNe

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