One of the most successful developments of the St. Petersburg specialist - Andrey Fedorov (nickname Andy_F) - is the IB (induction-balanced) metal detector Kvazar ARM, a more advanced version of the popular Kvazar. In the second version, a modern and very high-speed microcontroller of the STM32 family was used, which allowed the new device not only to greatly improve the speed indicators (the first Quasar slowed down, which is already there ..), but also to acquire features characteristic only of top branded models - such as an automatic tracking ground balance, electronic semi-automatic sensor unbalance compensator, etc.

Along with very impressive search characteristics, Quasar AWP is distinguished by a very high repeatability and independence of characteristics from the subjective parameters of the components. This means that you do not have to select capacitors, go through dozens of microcircuits, trying to find the "least noisy and bugless", etc. A properly assembled and wired device works immediately and does not require any "low-level" adjustments - everything is done from the menu using the software. Separately, it is worth highlighting the self-diagnostic system embedded in the program, which, using a blinking LED, can report the problem with which of the controller outputs, if any. One cannot but praise the built-in tools for configuring and monitoring sensors: everything is extremely simple, automated and bug-free. In general, bug-freeness is a distinctive feature of this device. A simple but very competent circuit together with a "polished" program almost does not give a chance for error, so I dare to recommend the Quasar AWP as the best home-made device today in terms of its characteristics. In this case, not scarce and not expensive parts are used. I would like to note that I spent an intensive search season with this device, and besides a lot of positive emotions and finds, I did not receive any negative. A stable, tenacious and deep apparatus that becomes, as it were, invisible - you just hear and see what is under the sensor. At the same time, there are still reserves of processor power and the author does not cease to improve the firmware, mostly following the requests of user-diggers. There is an excellent forum, where you can get a lot of useful information, including a branch on the Quasar AWP. But since it has hundreds of pages, where it is difficult to find grains of knowledge among the mass of incompetent opinions, I took the trouble to somewhat systematize and summarize everything that I had time to study and learn about this wonderful device. But I want to note right away that the manufacture of this device requires certain skills and at least basic knowledge of radio electronics. Of the instruments, a multimeter is needed, an L and C meter is highly desirable, at least a simple oscilloscope will not interfere.

So, brief characteristics:

• Operating principle: induction-balanced, single-frequency
• Operating frequency: 4 ... 20 kHz, depending on the sensor
• Sensor type: resonant TX (serial circuit) + resonant PX (parallel circuit)
• Operating modes: dynamic and static
• Display: LCD or OLED, 2x16 character spaces
• Display: Signograph 16 sectors, same + VDI digits, large VDI digits
• Indication of ground condition and battery charge
• Low battery warning (beep), threshold configurable
• Dynamic and static response strength indication
• Backlight status indication (Signograph mode only)
• Sector masks (prohibition of voice acting) - optional
• Switchable Treshhold with volume control
• Voice acting: two - three - and multi-tone (3 sound schemes), with the ability to adjust the volume gradation from the signal level
• Ground balancing: manual, semi-automatic and automatic with adjustable tuning speed
• Sensitivity adjustment (threshold): 32 gradations
• Sound volume control: 32 gradations
• Backlight intensity adjustment (if available in the applied display): 32 gradations
• 3 user profiles (all settings are saved)
• 4 filters for different search conditions (equivalent to the Reactivity parameter in XP DEUS)
• VCO pinpointer mode, with adjustable threshold and sensitivity
• Electronic compensator for sensor unbalance
• Power supply: from 6 to 15V, average consumption 150..200mA depending on settings
• Built-in sensor customization tools
• Self-diagnosis when turned on

Quasar ARM - this is one of the most popular metal detectors, the circuit and firmware of which are freely available on the author's website, for which special thanks to him. The capabilities of this device take it on a par with many commercial and expensive models. The author is constantly improving his creation and from time to time releases new firmware, each of which gives the device new capabilities, increases its stability and accuracy in determining the type of metal. In this article I will tell you how to update the firmware of a metal detector using my device as an example.

So, if you are the lucky owner Quasar ARM and want to refresh it with a new firmware, please read the instructions below carefully.
As you know (or do not know), a microprocessor serves as the brain of a quasar STM32F100C... And as much as we would like to reduce the complexity of its firmware to a minimum, we still need a special USB-TO-TTL programmer. Of course, you can assemble it yourself, but it is best to buy or borrow it from a friend for temporary use. Such programmers are sold in radio stores. Personally, I took mine on Aliexpress... For specifics, here are photos # 1 and # 2, in which the required programmer is shown from both sides.

Photo # 1 - programmer - top view

Photo # 2 - programmer - bottom view

After you have the programmer in your hands, you need to properly make friends with the operating system. I have installed on my computer Windows 10 and I confess that I had to smash my head a little to achieve a positive result in this direction. So, if you haven't saved up for MAC and use standard Windows, do the following: insert the programmer into any port USB computer and go to the task manager to see how it was defined in the system. Most likely you will get something like the following picture (photo # 3).

Photo number 3 - a problem in determining the programmer

From the above photo you can see that Windows defined the programmer and assigned a virtual port to it COM9... However, a small exclamation mark next to the device name indicates a problem with the driver and, as a result, the current inoperability of the programmer. This can be fixed by installing a special driver, which I managed to find on the Internet far from the first time. So, download the driver from this link: (downloads: 217)
Next, unpack the archive and get several files, as in photo # 4.

Photo # 4 - unpacked archive with drivers for the programmer

Run the executable file from the archive and wait for the end of the installation. After that, we return to " Device Manager", we find the line with the name of the programmer (Photo # 3), move the mouse cursor over it, press the right key and select" Update driver". The system will offer to install the driver automatically, or from the specified location on the computer - we tend to the second option, not forgetting to specify the folder with the unpacked archive, as in photo # 5.

Photo # 5 - choosing a folder with drivers

Most likely, after pressing the " OK", you will be prompted to install one of 2 drivers to choose from. You must select the one with an older version, as shown in photo # 6.

Photo # 6 - installing an earlier version of the driver

We press " Further"and wait for the end of the process. Now the programmer should be correctly detected in the system. To check this fact, reopen" Device Manager"and pay attention to the line where the exclamation mark was. If everything went well, it should disappear, as shown in photo # 7.

Photo # 7 - correct definition of the programmer (no exclamation mark)

So, the programmer is installed, it remains to configure it correctly. Right-click on the name of the programmer in " Device manager"(photo # 7), select the item" Properties"and in the window that opens, go to the" Port parameters". Here you can configure the port speed and the algorithm for communicating with the program through which in the future we will flash our processor. Set the values \u200b\u200bin accordance with the photo # 8 below.

Photo # 8 - correct settings of the programmer port

From this moment on, the first and most unpleasant stage is completed. The only advantage is that it must be performed once. With subsequent firmwares, programming is not required. Now let's decide on how to connect the programmer to your metal detector. In most cases, special pins for connecting the programmer are wired and signed on printed circuit boards. In my case, the pins were unsoldered, but not signed. It looked something like this (photo # 9).

Photo # 9 - unnamed programming connector

If you have a similar situation, then you should pick up the tester and call everything according to the diagram below (photo # 10).

Photo # 10 - programmer connection diagram

In this diagram, I depicted a way to connect the programmer to the microprocessor, regardless of the type of printed circuit board on the basis of which your Quasar ARM... This is the classic way of programming UART interface... A few explanations on the diagram. IN 99% cases the microprocessor you will have in the case LQFP48... The numbering of his contacts begins with a small round icon and goes counterclockwise. For clarity, all the necessary contacts are signed on the diagram with their numbers in brackets. Pins RX, TX and VSS microprocessor are connected directly to the programmer. Output BOOT0, serves to translate STM32 into programming mode. To enter this mode, you must close BOOT0 with power output VBAT, otherwise the processor will simply start up and operate normally. Later, I will give a specific sequence of actions so that there is no confusion in your head.
We figured out the connection - you can download the software for programming. Typically microprocessors STM32 programmed using a special proprietary program Flash Loader Demonstrator... It is free and available on the company's official website. Installation should not cause any difficulties, so I will ignore this moment. Next, go to the author's website and download the latest firmware version. At the time of this writing, the most recent version 2.3.3 , as evidenced by photo # 11, but I prefer the more stable version 2.2.18 .

Photo # 11 - the firmware I have chosen for recording in the MD

The downloaded archive must be unpacked and a file with the extension .hex... This is the firmware binary file. Now you can proceed to the final and most important stage.
First of all, we connect the programmer and close the output with a jumper BOOT0 and VBAT microprocessor. We insert the programmer into the port USB and supply power to the metal detector. If there is nothing on the screen, then we are on the right track and the microprocessor has entered the programming mode. At the moment, you should have approximately the same picture as in photo # 12

Photo # 12 - the jumper is closed, the programmer is connected, the power is on

Photo # 13 - connection settings

These are the connection settings by UART protocol... The indicated numbers must exactly match those that we set in the programmer port settings window (photo # 8). Parameter Port Name - the name of the virtual port assigned Windows programmer. It will probably be different for you. This name can be seen in " Device manager"using the example of photo # 7. When all the settings are set, press" Next"to proceed to the next stage (photo # 14)

Photo # 14 - the program saw the microprocessor

The FAQ section was created for the convenience of obtaining basic information about metal detectors. Here you can find a description of how to set up, video instructions, diagrams, etc. Answers to frequently asked questions. We recommend everyone who is interested in this or that device to start by studying the information in this section. You can fill in the information in this section by contacting the administrator. We welcome the participation of each forum participant. As the section is filled with information, each of us will be able to fully study the device of interest, its capabilities and characteristics, receive information assistance as a foundation for subsequent successful development and maximum effective use.

• Quasar ARM

• Quasar ARM is a selective metal detector with an LCD screen and the distribution of metals into 16 groups. This is a continuation of the project of the Kvazar metal detector. The new circuit uses a more powerful ARM32 microcontroller and adds additional features. This metal detector has an average level of difficulty, for DIY playback! Only people with experience should undertake its production. There are smd components (which can cause difficulties for a beginner), a programmable microcontroller, and a coil for an IB metal detector with which a lot of trouble also arises, in the absence of proper experience. But if all these nuances do not bother you, then the device will delight you!

  Technical characteristics of the metal detector Quasar ARM:

  • Working frequency - from 4 to 16 kHz;
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  • Indication - audible multi-tone and visual LCD screen.
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  • Power supply - 12 volts.
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  • The detection depth of a 5 kopeck coin of the USSR (with a 23 cm DD coil) is 30 cm.
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  Improvements in the new Quasar AWP:

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  • Removed external ADC, which was difficult to acquire.
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  • Frequency range from 4 to 16 kHz.
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  • Improved sound quality.
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  • Added three profiles to save and restore settings (A, B, C).
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  • Electronic compensation has been introduced to eliminate coil unbalance.
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DIY metal detector Quasar ARM

Metal detector Quasar ARM Is a balanced selective metal detector with metal discrimination and an LCD screen. Quasar AWP is a continuation of the project of a metal detector based on an AT Mega32 microprocessor "Quasar AVR". The updated device circuit uses a more powerful ARM32 microcontroller, and implements additional features, which will be described below.

Technical characteristics of the metal detector Quasar ARM:

• Power supply 6-9 V

• The principle of operation is single-frequency, IB.

• Working frequency - from 4 to 20 kHz;

• Indication - audio multi-tone, and visual LCD screen

• The depth of coin detection is 5 kopecks. USSR (with coil DD 23 cm) - 30 cm.

• Electronic compensation to eliminate coil unbalance.

• FM modulator for wireless headphones

• Coil current adjustment unit

• Self-diagnosis of the device when turned on

Quasar ARM metal detector circuit

Printed circuit board Quasar AWP

This board is made for surface mounting elements (SMD), which significantly saves time and money for the manufacture of a metal detector Quasar ARM. The board provides cutouts for installing the coil and power connectors. The dimensions of the board are designed for the very common Gainta 1910 case.

Parts list of Quasar ARM

Instructions for assembling the Quasar AWP board from the author of the board

Metal detector board Quasar ARM rev.05а is intended for self-assembly of a selective metal detector Quasar ARM. The scheme differs from the author's in some modifications:

• Protection against polarity reversal of the power supply has been improved taking into account the minimum voltage drop in this node.

• There is an electronic power cut-off from the front panel with a button. In the off state, the metal detector does not consume current, thereby eliminating consumption when the device is off.

• The display is powered from a separate voltage regulator, the voltage level of the display being 3.3 V or 5 Volts is selected by the type of installed voltage regulator.

• The board has the ability to assemble a current adjustment unit in the search sensor

• The board has the ability to assemble an FM transmitter assembly for connecting wireless headphones

• The board is designed to be installed in a factory serial Gainta G1910 case

Do-it-yourself quasar AWP board assembly

The fee is collected in several stages:

1) Assemble the battery polarity reversal protection circuit, the power supply circuit, solder the power stabilizers. Check the assembled units for operability. Power management: briefly press the power button - the power turns on. Press and hold the button - the board is powered off.

2) Collect the rest of the device, wash the board using special tools or an ultrasonic bath.
3) Flash the STM32 processor via USART or SWD interface.
4) Connect the display, turn on the device, adjust the screen contrast
5) When you install the FM transmitter, the sound automatically switches to it, you must turn off the FM transmitter in the settings menu to output sound to the speaker.
6) Connect the device to the search sensor, configure, check the functionality.

Some nuances when assembling the board:

Jumper JC2 is shorted when

• You do not install the FM transmitter on the board or the version of the selected firmware is lower than 2.2.2, in this case, if you do not install the JC2 jumper, the sound will not be output to the speaker

Jumper JC1 is shorted when:

• You do not assemble the current regulation unit in the search sensor (circled with a yellow marker), while you need to install a stabilizer (green marker) LM1117-5.0 and a 10 Ohm resistor R10, in the case when the unit is going you need to install LM1117-ADJ and R10 5, 1 Ohm

Display Power Stabilizer:

• It is recommended to install the stabilizer LM1117-5.0 for a regular LCD display, for OLED - LM1117-3.3

Mounting the display on the metal detector board

FM transmitter elements inhighlighted with a yellow marker, the elements indicated by the green arrow must be sealed in any case.

Assembly into the case and fixing the board:

• Install the board on the back of the case and mark the holes, drill holes for times b eat power supply and coil connection

• Paste add. racks according to the selected height 3 or 2 mm

• Install connectors and speaker

• Install and fix the metal detector board

• Cut out holes for the display, buttons according to the drilling in the top cover. Headphone jack hole is marked after the fact

Metal detector « QUASAR- ARM”, A modern digital IB metal detector built on a fairly new and modern STM32 controller.

This one has many useful features and menu device settings.

What is very pleasant is the use of a wide range of operating frequencies (one to choose from, automatic selection of frequency to resonance for the search sensor, etc.), as well as 8 user profiles (which can be saved or recalled from the menu).

Despite my skepticism about digital metal detectors, after the first time I went out with it, I practically "fell in love" with it. What I can't say about many branded devices !!!

Technical characteristics of the metal detector Kvazar ARM with a search sensor DD- 20 cm:

Coin with a diameter of 25mm (ground)…. up to 35 cm

Helmet …………………………………… .. up to 1.2 m

Maximum …………………………. up to 1.7 m

Sound indication to choose from ... ... ... ... from 2 tones or more

Visual indication VDI ………… .. yes

Installation of masks for types of metal ....... is

Operating principle ……………………… .. IB (inductive balance)

Sensor diameter ………………………… from 15 to 30 cm

(optional)

Operating frequency range ……………. from 6 to 20 kHz

(depends on firmware)

Supply voltage ………………… 3.7-5.5 Volts

Consumption current ……………………… about 100-180 mA (depending on settings)

Here is a view of the assembled device board (photo below).

... I didn’t want to make a payment, as well as to buy a completely finished device, so I limited myself to buying an empty board from This e-mail address is being protected from spambots, you need to enable Javascript to view it. (with a soldered, wired controller). Fortunately, this is now very possible and at divine prices.

The circuit of the device turned out to be very simple and I decided to assemble and configure this device myself. I had all the necessary equipment for this.

The collected board looked like this ...

The assembly and configuration was facilitated by some files, kindly provided. This e-mail address is being protected from spambots, you need to enable Javascript to view it. ...

You can download all this, as well as the instructions for the Kvazar-ARM detector.

A short video about the modes, operation and configuration of the sensor:

Well, now about my impressions:

The assembly was short-lived and very pleasant, as the board was made at the highest level (mask, part numbering and footprint).

The device started immediately and obeyed the keyboard commands;

After making a 20 cm DD sensor, the device (or rather its software capabilities) helped in setting up the sensor ...

With a 20 cm sensor, it showed good results and target selection;

Tested in a sealed plastic case under immersion conditions (chest-deep).

Confident work in the water and target selection.

Here is a short video from my release.

Well, in conclusion, I want to say: "I have not yet held the best domestic device in my hands!"

In the conditions of salt and sea, I have never used the Quasar ARM (and there are doubts, until I try it personally) ...

Well, for these purposes (sea search), I am collecting myself another device. Well, for those who want to have such a device, but are afraid to assemble it on their own, I am always ready to help. This e-mail address is being protected from spambots, you need JavaScript enabled to view it. ...

Metelodetector QUASAR- ARM will be a pleasant helper in your search. Enjoy your search!

Alexander Serbin (Kharkov)