QUASAR ARM (Quasar ARM) is a metal detector with direct processing, developed on a modern basis using an ARM processor.
Main characteristics of the device:
Main characteristics of this assembly:
Sensitivity:
Equipment:
It should be especially emphasized that the quality of the Quasar ARM metal detector (I prefer the Latin spelling Quasar ARM) fundamentally depends on the quality of manufacturing and layout of the printed circuit board (there are more than ten options sold, and not all are good), the quality of components and installation, and especially - on the quality of the sensor. Therefore, it is funny to read negative reviews about the device as a whole, based on the experience of assembling clumsy parts from parts found in the trash. Moreover, judging by information from various specialized forums, such ugly crafts make up the bulk of the instruments and sensors offered for purchase. Faster, cheaper, and that will do - apparently, this is the main goal of most sellers (I by no means speak for everyone). Of course, this approach entails a lot of negative reviews about the device, although it would be wise to write a review about the manufacturer. To set up a Quasar workstation well and make a decent sensor, you need not only knowledge and experience, but also normal measuring equipment, not to mention the ability to use it. Craftsmen often make do with a Chinese tester from a flea market... this is also possible, but is it worth expecting a good result? Another point, many “Kulibins”, without even having basic knowledge in the field of electronics, try in every possible way to “modify” and “improve” the author’s circuit (I often cite it as an example of high-quality development), created by a professional. Based on these, so to speak, improvements, printed circuit boards are then hastily laid out and immediately put on sale. What can I say... only that such crafts have nothing to do with the real Quasar ARM and any reviews about such “Quasars” are nothing more than a painting of one’s own incompetence. Here and further we will talk exclusively about devices assembled with direct hands according to the author’s scheme.
Quasar AWP, assembled by me on the author's board revision 1.4, the firmware current at the time of writing this review is version 2.2.10. A family of homemade sensors from a sniper rifle to a “steering wheel” for medium frequencies of 7..9 kHz. The scheme is the author's, no changes.
I can immediately responsibly declare that a Quasar AWP correctly assembled from high-quality components, equipped with a well-manufactured sensor, has search characteristics that are often superior to the top-end devices of leading manufacturers in their segment (single-frequency ground-based IB devices). This does not negate the mandatory understanding of the principles of operation and the ability to configure the Quasar workstation for specific conditions, as, indeed, any branded metal detector.
In addition to Quasar ARM, I collected and tested analog devices such as Tesoro Vaquero and Lobo, Whites Classic in different variations, some ancient Fisher... they were all single-tone, I personally didn’t like it. The plans are to build something like Golden Mask 4, two-tone analog... but these are plans. From digital cameras I collected Quasar AVR, pulse variants of Clone (author Andy_F), Fortuna-M. Among the branded ones were “Koshchei-25K”, Terka-705, I tried new digital Whites, now I use Deus (studied and touched up and down). This is all to say that I have something to compare with. It may seem to some that I am “singing praises” to the device... this is not so. He, like everything in the world, has shortcomings, I will definitely write about them. Therefore, without false modesty, I can say that my review of Quasar AWP will be objective and honest.
So, from the very beginning.
Schematic diagram. As an electronics engineer by training and hobby, I rate the circuit 4.9 points out of 5.0. Here it is appropriate to quote a teacher-professor: “Only the Lord God knows the strength of materials perfectly, I know a B, and all of you (students) know a C at best!” No matter how much I looked at the diagram, I couldn’t improve anything (I’m not a guru, of course, but I have experience in development and implementation in production). Do it differently - yes, but improve it - no.
Printed circuit board. From the point of view of signal wiring, the author’s one is good, but it’s a little difficult to make on your own due to the large number of vias, and it was also originally designed for a non-standard and scarce type of display. You can install a regular one on it, with a couple of “extra” wires, this is not critical. Otherwise, it’s one of the best, if not the best. There will be a separate review about all other boards.
Components used. Widespread, not scarce and not expensive. The total cost does not exceed $40 if you buy everything new. It is better to use an OLED display, but it is somewhat more expensive than a regular LCD.
Repeatability. High... no, highest. Everything works without any adjustments to the hardware, the main thing is to assemble it correctly from serviceable components and properly rinse the board from flux. The operation is practically independent of the variation in the parameters of the parts - a sign of a high-quality circuit design.
Flexibility of settings. Everything you need for an effective search. It is especially worth noting the perfectly working sensor imbalance compensator (allows you to work normally even with a “floating” sensor, or with an “almost suitable” factory one), switchable automatic ground balance with adjustable reaction time, a set of ground filters (speeds) for all occasions, 8 memorized profiles , arbitrary mask for voice acting. Vector cutting of soil, allowing you to very accurately “cut” it without loss of range (well, almost without loss). There is a static pin mode with discrimination and VDI display. The set of settings corresponds to a professional level, so it is advisable to understand the issue a little and not use it at random. However, by default everything is fine.
Voice acting, display. Three voice-over schemes, including polyphony (scheme 1), which I consider the most informative. The sound is soft and pleasant. Adjusting the volume of weak signals, several additional ones. options, including thrashhold. 16-sector signograph, display of VDI number, signal strength, battery charge level, current ground angle, transmitter current. Signograph display delay adjustment. Again we see a set for a professional. Very informative and convenient. The latest versions of the circuit and board have a built-in FM transmitter for using wireless headphones. It works great, all adjustments are in the menu. Do you know many devices with wireless “ears” by default and with transmitter adjustments?
Depth. Depends on the settings, mainly on the filter. The threshold also affects. The slower, the deeper. On the slowest filter with threshold 3, with a DD25cm sensor, you can “feel” a patch of tips at 35..38cm. This is in light soil, for example, Deus with a 28cm sensor catches only barely better, “at the end”, at similar “depth” settings.
Identification and division of goals. In fact, everything here depends more on the sensor and settings. But if we compare with identical sensors, then at maximum speed the Quasar ARM approximately corresponds in speed to the Deus in “second gear”, that is, Reactivity = 2 (out of 5). Very good, with a small sensor on the garbage it is very comfortable. The separation with the appropriate filter settings is excellent, the separation of color against the background of black signals is also at the Deus level, no subjective differences were found. If they see, then both devices, if they don’t see, then both.
Stability, overall comfort. On high. If the same Deus with “quiet” settings turns into a pumpkin, then the Quasar ARM almost does not lose in depth. That is, with a normal Quasar, it is more comfortable to search for an automated workplace than with a Deus, this is in clean places. In the trash, Deus has no equal, but if there are not many signals, you can walk with Quasar in almost silence, and Deus will be a little babbling - but he is also somewhat deeper. Quasar ARM is one of the most comfortable in search of all the devices that I have had.
Flaws. What would it be like without them... true, they are all subjective, but still. To begin with, I don’t like the small number of voice-over schemes and the inability to customize the frequencies and volumes of the sectors to suit you. In the same Koshchei-25K, Fortuna-M it was and it’s convenient. I really hope that the author will eventually listen to this opinion, it is not only mine. Then the speed, it (after Deus) seems a little insufficient for strong trash cans. In pin mode, sometimes (rarely) it “starts up”, it is cured by resetting it with the “left” button (this binds to the current response level). I’m attracted to the ears: for an effective search it requires some knowledge in this area, an understanding of the physics of processes. However, like any other professional device.
Conclusion: Quasar ARM is, in my opinion, the best of the home-made devices in terms of the totality of characteristics. No more, no less.
Quasar is a selective IB metal detector with metal recognition and direct signal processing. The VDI scale in Quasar is divided into 16 columns, with the ability to remove any of the columns from the search (Closing them with a mask) as well as audio multi-tone indication. In the latest firmware versions, the Quasar's operating frequency can be up to 17 kHz and depends on the search coil.
The Quasar metal detector circuit has an average level of complexity (The only component in short supply is the MCP3201, so there is already a metal detector circuitand Quasar AVR where, thanks to replacing the microcontroller, this problem was also eliminated). But the presence of a programmable microcontroller and coil for Quasar, as for any other selective metal detectors, creates some difficulties for radio amateurs. The manufacture of Quasar is carried out by people with experience in the manufacture of metal detectors. In general, the Quasar metal detector has medium difficulty level for making it yourself.
Download the Quasar metal detector diagram in pdf format —
The presence of an accessible screen makes the Quasar a very convenient and easily repeatable metal detector with metal recognition.
Working screen of the metal detectorQUASAR as follows:
Metal detector discrimination scaleQUASAR divided as follows:
The KVASAR metal detector is controlled by 6 buttons:
Firmware for the Quasar metal detector Version 1.4.5 (the latest firmware version for today) –
For flashing the microcontroller of the Quasar metal detector, programming fuses must be arranged as follows:
The developer of the Quasar metal detector gives a brief description of the search coil he made. Coil type DD with outer diameter 230 mm. TX – 40-45 turns with 0.5 mm wire and RX – 200 turns with 0.2 mm wire. The TX winding is connected to a metal detector with serial resonance, the capacitance of the capacitor is 0.3 mF, the resonant frequency is 8.192 kHz, the RX winding is connected to a metal detector with parallel resonance, and is adjusted to a frequency 1.5 - 2 kHz below the TX resonant frequency.
Below is diagram for connecting such a coil to the Quasar metal detector
Description of launching and setting up the KVASAR metal detector with oscillograms -
Description of the menu and settings in the Quasar metal detector -
Conclusion: The QUASAR metal detector has a simple circuit and inexpensive components (microcontroller, screen, etc.), which makes it very attractive for self-production. In operation, Quasar shows quite pleasant characteristics and good results, and can easily compete with entry-level branded metal detectors.
The metal detector project received its continuation in versions and QUASARAVR, Therefore, it’s worth starting to manufacture these particular versions of the metal detector, since the author has stopped releasing firmware updates for QUASAR!
When writing, materials were used from the author’s website - http://fandy.ucoz.org/
All questions about the Quasar metal detector can be asked in the comments to this article. And also write your review, wishes and suggestions for adding to this material.
And so, in the article we’ll talk a little about the Quasar Avr metal detector, look into history, analyze the characteristics and consider all aspects related to its creation.
Quasar AVR metal detector - this device is based on the principle of inductive balance, or, in simple terms, IB. Selective and has VDI, 16 discrimination sectors, each can be closed. All spare parts, according to the author, are available. Direct signal processing.
Quasar technical characteristics:
Overall, this is a fairly complex metal detector to assemble. It’s definitely not suitable for beginners; there’s a lot of hassle with both the board and the coil. But if you are a more or less experienced fighter, then reserve your strength and move forward.
In principle, there is nothing to say about the diagram; you need to look and figure it out yourself, all on your own and with your own hands. Here is a picture of it and below is a link to it.
Now let's talk about how to make a coil for a quasar. For a quasar, a DD sensor is used, which has the following parameters:
The connection diagram itself looks like this:
As you can see, TX is connected according to a circuit with a series resonance, and RX is connected with a parallel one. TX is adjusted to a frequency from 4.5 to 9 kHz, in RX to a lower frequency - from 1.5 to 2 kHz.
Let's talk a little about the settings of this device, what operational settings it has. This means that the Quasar Avr metal detector has the following settings:
We've finished setting up the quasar arm, now let's talk about the firmware.
In principle, there’s not even anything to tell here, download the latest version on the author’s website or from us, and flash it. Here are images of how the fuses should be.
In general, the Quasar metal detector has received very good reviews. One of the most popular homemade devices, in many respects it can be compared with mid- and high-level industrial metal detectors. An excellent device that competes with many devices. Its subsequent versions are further developed. Beginners should think about it, because a quasar is cheaper, even if you order from someone else, than the same ICQ 150 or 250, and its characteristics are many times better. So think, decide. But if you decide to buy, the main thing is to find a good seller and manufacturer, so as not to suffer and swear at the device later. A lot depends on the manufacturer and build quality. Look for reviews.
And finally, a little video of a cop working with a Quasar metal detector.
