Quote: “I bring to your attention another option on how to make an original hard drive loading indicator. It is based on changes in voltage in the circuit, and converts these jumps into discrete values.”
Led indicator
loading hard drive -y for help
in creating a flash video
Introduction
I’ll make a reservation right away: I’m not a modder, so I didn’t follow the canons of the genre. I am primarily interested in functionality; I care little about the aesthetic side.
I bring to your attention another option on how to make an original hard drive loading indicator. It is based on changes in voltage in a circuit, and converts these changes into discrete values.
What you will need for this:
Radio constructor "LED level indicator". In Voronezh you can buy it for 55 rubles, which I do not recommend, since it is equipped with rather dim LEDs and is not worth the money. The only useful thing is printed circuit board. Parts will cost 15 rubles.
It is advisable to purchase a 2-10 kOhm trimmer resistor instead of R1.
LEDs (minimum 5 pieces).
Molex power connector (female). I combined my circuit with an existing device, so I didn’t need it. You can use any power connection method.
When connecting the circuit to 12 V, it is advisable to run the LEDs through resistors. It depends on what kind of LEDs you use - five-volt ones are unlikely to need resistors, but 3 V ones most likely will.
Wires, insulation/heat shrink, soldering iron (no more powerful than 40 W), soldering accessories, etc.
Notes
It all depends on the LEDs that you are going to use (each crazy person has his own program :-), or rather on their price. Personally, I used an LED line for 32 rubles. In total, all this cost me 90 rubles, and for me, the mod is worth the money.
In general, I want to say that this radio designer is not ideal - the more LEDs glow, the dimmer they glow. The problem is partially solved by increasing the voltage (12 V instead of 5 V) and connecting the LEDs through resistors (470-510 Ohms). But no one forbids you to try another similar indicator - for example, you can search in “CHIP and DIP”. So there is a lot of room for further development here.
This circuit provides 5 discrete levels of indication. We can see something similar to this in the Winamp visualization in the “Spectrum Analyzer” mode.
Of course, many people have the first desire to adapt this product for music, BUT... Since I have enough indicators for music (and sounds in general), because instead of speakers I use the center, and it has a 7-band equalizer, and even in Winamp" We don’t have one, so we won’t go into pop music and slightly diversify the scope of application.
The mod is quite simple and cheap to implement, especially for those who have been dealing with radio electronics for a long time. Let's assume that everyone knows the soldering phase (editor's note: those who don't know, read) - that is, they soldered the circuit, adjusted the power supply, distributed the LEDs by color and pins (be careful - the circuit is non-standard!) - so let's move on to the first test.
If you buy a radio designer, you should get something like this
Why "something" - because I slightly modified the diagram. I connected the blue LED so that it was lit constantly (that is, separate from the circuit). It symbolizes the “cold” boot of the hard drive, that is, the zero level. I combined LEDs 2 and 3 into level 1, and LEDs 4 and 5 into level 2. I could initially use an LED strip with 5 LEDs, but I made the mod with an eye to the future, if I suddenly find a circuit for 7-8 LEDs, for more accurate indication. The white electrolytic capacitor is not present in the original circuit; in mine it acts as a voltage stabilizer.
Connecting the power
Hint: If you hold only the positive input with your fingers, then perhaps the first or second level will light up. This means that the scheme is working.
Now we try to connect the inputs parallel to the HDD Led (that is, usually the red dim LED, but you already have it DIFFERENT, right?). My LED is connected through a special connector (white in the picture on the right), so connecting the indicator was not difficult. Those who have LEDs soldered and insulated will have to tinker a little.
Here was the first surprise. Initially I wanted to use 5V power, but this circuit had one drawback (see above). When connecting the circuit to 12 V (and adding resistors to the LEDs), the inputs connected to the HDD Led gave reverse currents, and made this same HDD Led glow at full intensity. Perhaps due to the fact that I have a sensitive red LED (with which I replaced the original dim one). By removing the input ground from the diagram, I got the desired result. This is even better - less wires. If everything works fine for you with 2 wires connected, then leave it like that. (In the picture, the remaining input is the blue wire going to the red wire in the connector)
I would like to note that this mod is not a complete replacement, but an addition to the main indicator. If HDD Led shows (relatively speaking) the channel load level (how large volumes of data are transferred), then the peak indicator displays how often (at what speed) data is transferred over the channel. If you do not need to monitor the hard drive, then you can leave only the new indicator. Personally, I now have both indicators on the front of the system unit (for reference, the height of my LED line 4 cm).
Adjustment
Most likely your tuning resistor is small and without a handle, so here we arm ourselves with a small (narrow) screwdriver and start driving the hard drive. Personally, I took as a basis the operations of archiving small files (web pages), archiving large files (clips, for example), watching a movie through Windows Media Player, copying from one logical drive to another within the physical medium. You can also try copying from one hard drive to another, or run Scandisk. We look at how the hard drive behaves, twist the resistor to set the oscillation range of the indicator. In general terms, the point is to create various situations: weak hard drive loading (small volume in rare portions) and heavy hard drive loading (large volume in an almost continuous flow). In the first case, the peak indicator should twitch at level 1-2, in the second case, levels 1-4 will light almost constantly, and level 5 will light or blink. Where to place the LEDs, circuit, etc. - that is, aesthetic issues - this already depends on everyone’s imagination. Personally, I hid the circuit in the front box, and brought out the LEDs on the left side (on a grand scale for the future - I want to make a similar circuit for the Mobile Rack on the right).
Illustration of work
Full load
HDD LED indicator in operation
High load 
Average load 
Low load Zero load Additionally
Advantages of this mod
1.
Conceptually new element in design - a great addition to any technogenic computer
2.
Some usefulness. Having two indicators has already helped me several times. For example, do not reboot the computer again (there was a suspicion that it was frozen - but the indicator twitched - and after 5 minutes the machine recovered!). Or, on the contrary, feel free to press Reset - the boot LED was constantly on, and the peak one was at zero - sure sign hang"a
3. Originality
Flaws
1.
The one that was described above in the article - the voltage is distributed among all working LEDs. However, at high voltages this is not so noticeable. And the pulsation gives “liveness” to the modified (and genetically altered:-) computer.
2. The very first question of everyone to whom I showed the mod: “Does it react to your music?” TIRED, honestly
One of the most common computer mods is replacing the standard LEDs on the case with some others. However, you must admit that this is too simple. Why not make a kind of VU hard drive loading indicator using several LEDs? Something like a VU-meter on amplifiers.
A suitable diagram was found on the above site:
It's simple. Power supply +5V, on the left in the diagram. At the bottom right, to the outputs of the optocoupler LED (legs 1 and 2), we connect the outputs on the mother, called HDD Led. If you reverse the polarity on this LED, nothing bad will happen, the LEDs will simply not light up. But at the +5V input, it is advisable not to confuse the polarity.
The advantage of such a circuit is that the HDD Led signal from the mother is not used by your circuit directly (the change in the resistance of the emitter-collector junction of the optotransistor in the optocoupler is used). And, therefore, if you connected the mother to the correct outputs of the optocoupler, then no matter how incorrectly your circuit is assembled, it will never damage (read: cover) the mother. :-)
The jumper in the diagram determines the operating mode of the LED scale. If it is closed, then the LEDs light up one after another from right to left (according to the picture), if it is open, then only one LED will always light up, i.e. you get something like a “jumping dot”. Because I didn’t like the last option, so I made the circuit without a jumper (I simply shorted this section).
So, let's look... What we need for this:
- LM3914 itself is, in fact, a microchip that controls LEDs (led bargraph driver chip);
- 4N25 (or 4N26, or 4N28 or TIL111) - optocoupler (optoisolator);
- Electrolytic capacitor: 220 µF at 25V (with a voltage reserve);
- Resistors (one piece each): 3.3KOhm, 10KOhm, 470Ohm, 330Ohm, all 0.25W.
- LEDs for 2.5-3.5V - 10 pcs, cool - multi-colored.
Because I found the diagram on an import site, so first I decided to assemble everything on cardboard and wires to check its functionality, check it out:
For testing purposes, I was too lazy to solder all 10 LEDs, so only five pins from the main device were used. Since I checked it worked, you can skip this step :-).
For ease of connection, you can also stock up on the following components:
- Colored wires (black and red) for connecting to the mother and power supply;
- Molex connector for connecting to a standard power supply; you can buy 2 (male and female for attaching to a wire) and make another coupler if there are no free connectors on the power supply;
- Thin wires, a cable, or a block with screws on a board for connecting LEDs;
- Beds for microcircuits (18 and 6 legs) - highly recommended;
- What you will solder this whole thing on: circuit board, foil PCB/getinax, cardboard (ghetto-mod:-)).
In principle, it can be made more compact, but that was not my task. Don't forget the mounting holes in the board if you need them!
I made the board as follows. I didn’t want to get involved with ferric chloride, varnish and solvent, so I glued a board printed on paper in a 1:1 format with an adhesive stick onto the PCB from the foil side (laugh in vain, it [the adhesive stick] is easy to use, provides good adhesion of the paper to the foil and , at the same time, the paper is easy to tear off later without the use of additional tools). I drilled holes in it just like that. I tore the paper off the foil, connected the required holes with a pencil according to the board layout, and cut out the tracks with a knife. The holes for the power wires can be made with a diameter of about 1.5mm if you are going to use standard wires from the power supply (I did so, taking them from an old power supply).
In general, there is nothing complicated here, but you need to very carefully solder the narrow paths going from the microchip to the LEDs, because There are a lot of them and you can’t make them thick. Although I soldered a lot at one time, it was still not very easy... The main thing is that after cutting, thoroughly clean and degrease the board before soldering. The better you clean/degrease, the easier it will be for the tin to stick to the foil and the less chance it will come off the board. It is better to solder immediately after stripping, and all the elements at once, without putting it off until the next day, otherwise, if you solder half of it today and, without treating the board in any way, leave it for a week, then you will have to hemorrhoidally clean the pads again or heat them up more strongly with flux, from which, most likely, the tracks will come unstuck.
Here's what I got:
I decided not to mess with a bunch of LEDs and installed a set of ten LEDs in one housing, connecting it to the board with an 11-wire cable, cutting the cable from the drive accordingly. I soldered the cable directly into the board, but only then did it occur to me that I should have installed a connector there.
I highly recommend using cribs for microcircuits. Firstly, you won’t overheat when soldering onto the board (micrugs are inserted last), and secondly, if a mikrukh is found to have a manufacturing defect (not working, in short), then you can easily change it in the store where you bought it, and the soldered one will be yours will not be replaced.
When you have soldered the whole thing, you can check the functionality as follows:
- When power is turned on, no LED should be lit;
- If you close contacts 4 and 5 of the optocoupler (those that go into the circuit), then all the LEDs should light up (or only the last one, if you assembled a circuit with a break instead of a jumper).
If everything works, you can experiment, for example, with the order of connecting the LEDs, for example, so that the even ones in a row light up first, and then the odd ones, etc.
Analog hard drive loading indicator
For fans of analog technology, we can offer this option:
Those. Instead of a circuit and LEDs, you can connect some existing dial indicator with decent internal resistance, for example, from some kind of tape recorder. Use a potentiometer to set the current limit. We connect to the HDD-Led connector on the mother. Unlike the previous option, here, if you take a device that is too powerful and not very sensitive (with low internal resistance), you can easily damage the motherboard and then you will not have any HDD operation indicator.
The LED indicator (Light Emiting Diode, LED) of the hard drive (can be green, yellow or red) is usually located on the front panel of the case and is used to monitor the operation of the hard drive. Each call to the hard drive is accompanied by an indicator lighting up, usually Indicators, switches and connectors 33
indicated on the control panel system unit like HDD. Don’t be alarmed by the fact that the hard drive indicator is not constantly on, but flashes periodically. The point here is not a bad connection, but a visual display of quick access to the hard drive.
PC power indicator
The PC power indicator should always light up when you turn on the computer. The cable of this indicator is marked in most cases green. We are talking about a two-core wire that ends in a three-pin plug, with the middle pin not used. The color of the cable corresponds to the color of the indicator - green-black or green-white cable.
Typically, the PC power-on indication cable is combined with a KeyLock cable (PC keyboard lock cable). In this case, the cable is equipped with a five-pin connector. Motherboard manufacturers, as a rule, label all connector connections to the motherboard, so the corresponding terminal can be found without problems. The connection location of the KeyLock connector can be easily identified even without markings. Look on the motherboard for a single row of five pins, with one of the five pins missing. This missing pin is a kind of key for the correct connection of the connector.
Since this plug does not have guides, there is a high chance of connecting it incorrectly. The result of this error will be no indication of operation. In this case, you need to rotate the plug 180P.
Network switch Typically, the network switch is already connected to the power supply. If this is not the case, you should use the operating instructions and connect it.
Attention!
When purchasing, make sure that the switch is connected to the power supply. If there are no instructions, then entrust the connection of the network switch to a specialist. Due to the wide variety of power supplies, there is no uniform color coding for power switch terminals. Be extremely careful when connecting it! We are talking about a network voltage of 220-240 V.
By turning on the computer using the network switch, a cold start of the PC is carried out, i.e., the system starts from a state of rest (cold state). During a cold start, you should wait at least half a minute before turning on the computer again, since the mechanics of the drives require a certain time to completely stop.
Attention!
Frequently turning the computer on and off without pauses using the network switch can lead to serious damage to the floppy drives and hard drive.
After turning on the PC, the power supply performs a self-test for about 0.3-0.5 seconds. If all supply voltage levels are within acceptable limits, motherboard Power_Good signal is received. This signal is sent to the motherboard, where the clock generator chip generates the processor initial setting signal.
In the absence of a PowerGood signal, the clock generator chip will constantly supply the initial setting signal to the CPU, preventing the PC from operating with an “abnormal” or unstable supply voltage. When the Power Good signal arrives at the generator, the processor initialization signal will turn off and the PC test program (Power On Self Test, POST) stored in the ROM BIOS will begin. After successful completion of testing, the system will boot.
Some cheap power supplies do not have a Power Good signal conditioning circuit at all, and this circuit is simply connected to the +5 V supply voltage.
Some motherboards are more sensitive to an incorrect Power Good signal than others. Startup problems often arise precisely because of insufficient delay of this signal. Sometimes after replacing the motherboard, the PC stops starting normally. In such a situation it is quite difficult to understand, especially for an inexperienced user, who thinks that the reason lies in new board. But do not rush to write it off as faulty, because it often turns out that the power supply is “to blame”: either it does not provide enough power to power the new motherboard, or the Power Good signal is not supplied or is generated incorrectly. In such a situation, it is best to try connecting the motherboard to a different power supply.
Our regular readers are quite well aware of the work of specialists from the Cyber Security Research Center at Ben-Gurion University, Israel, who specialize in inventing unusual methods of hacking and stealing information from the depths of the most secure computer systems. And recently they managed to discover another potential source of information leakage, which is the familiar LED indicator that displays activity hard drive computer.
Let us remind our readers that computers that perform critical operations or contain top-secret information are in most cases protected by the so-called “air barrier”. This means that this computer is not connected to itself, nor to other computers connected to networks that have access to the Internet. This makes ordinary hacking impossible, and in order to extract information from the depths of such a computer, it is necessary to resort to very sophisticated tricks.
In their studies, the researchers found that by programming the sequence of program calls to the computer's hard drive in a certain way, it is possible to make the LED activity indicator blink at a speed of about six thousand times per second. This frequency is quite enough to transmit data at speeds of up to 4 thousand bits per second. Of course, transferring one megabyte of data at this speed will take a little over half an hour, but it will take very little time to transfer stolen messages, passwords, encryption keys and other similar information.
To use the hard drive LED as a transmitter, you will need to install it on the attacked computer special program-spy LED-it-GO, already developed by Israeli researchers. Currently, the operation of this system has been tested on computers running operating system Linux, however, researchers are confident that in exactly the same way it is possible to organize the theft of information from computers running Windows control. Positive feature this method is that all people have long been accustomed to the chaotic blinking of the computer hard drive indicator and are unlikely to notice changes in the nature of its operation. And the modulation of the LED glow with a frequency of several kilohertz is far beyond the perceptual capabilities of the human eye.
But ensuring the transmission of information through the hard drive's LED is only half the process of stealing information. The second part of the work can be taken over by a tiny spy drone equipped with a high-speed camera and photo sensors. The camera lens can be focused exclusively on the computer's LED, and then the sensitivity of the sensors will be sufficient to capture information even through the tinted glass of a closed window.
There are several options to protect against information theft in this way. The easiest option is to turn off the hard drive LED indicator. If for some reason this cannot be done, then you can position the protected computer so that its LEDs are not visible from any window in the room. And another, more complex option is to use a special program that accesses the hard drive at random intervals, this, in turn, will create insurmountable interference for any other program trying to transmit information through the hard drive's LED.
And, as a last resort, Israeli researchers advise simply covering the LED indicator with a piece of opaque tape. This method is a clear demonstration of how common and simple materials, such as a piece of ordinary electrical tape, can effectively counteract the most sophisticated and modern spy technologies.
One LED is used to indicate the loading of IDE disks, which is hardly very informative. I got tired of evaluating the load “by brightness” and I made a scale:
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The circuit can also be implemented in an integrated design, but I wanted to achieve a smooth and soft indication, which is difficult to achieve with ready-made microcircuits. However, I came up with the voltage-position converter itself a long time ago and it showed very good results in level indicators.Comment on the diagram
Relatively speaking, the circuit consists of two nodes - a circuit for averaging disk access pulses on R27, R26, D1, R28, R29, C1, C2, Q13 and a voltage-to-position converter on the remaining elements.
The circuit does not need any adjustment, only resistor R26 needs to be set to 100% when constantly accessing the disk. Circuit R24, R25, R11, Q11 sets the background current in the absence of a signal. If you want the last segment to be illuminated in the absence of a signal or, on the contrary, not to be illuminated, you need to slightly change the value of resistor R24 or R25.
The printed circuit board was not routed - I used breadboard“from nothing but holes” and SMD components, everything took up very little space, a little more than the indicator itself. The circuit is powered by +5V, pin P1 must be connected instead of or together with the “HDD LED”. If you mix it up and plug the “HDD LED” into the wrong pin, nothing will happen, there will simply be no indication.