It was necessary to output data from the GGA and VTG packages to the LCD, which when maximum size a package of 80 characters is not very convenient.

When debugging, we had to display data from the GGA and VTG packets on the LCD, which is not very convenient given the maximum packet size of 80 characters.

This disgrace was due to the fact that I had, which was inconvenient to use, in which something was always shorting out and threatening the precious COM port on my PC. I wanted to make a brand new, beautiful one, in a nice case and with beautiful wiring :) A scarf was etched, the wiring of which can be downloaded at the end of the note.

Next, the board was installed from ST Microelectronics (a complete analogue), but a couple of hryvnia cheaper. Of course, I respect Maxim, but I absolutely don’t like overpaying for trivial things. The capacitors in the harness were set to 1 µF 16V tantalum, type A.


Then all this stuff was stuffed into a building that I had lying around idle since I was 13 years old. I protected the wires from being pulled out with a simple knot. A soft cable with a connector for the COM port was borrowed from an old mouse.


A sticker with the designation of the wiring was printed and pasted on the case, so as not to constantly remember where is the plus and where is the minus :). A layer of adhesive tape protects it from abrasion. Now the converter has acquired some usability, and it has become convenient to use. Have a good day.

Through some simple manipulations (the description of which is more suitable for Habr), both the bootloader and the archive were installed on the memory card and the device was turned on. However, after loading, a black screen awaited me and the green LED on the “orange” was on.

Well, no problem, I thought. A UART is wired on the “orange”, I’ll connect to it using a terminal and see what’s happening. The necessary parts and wire were purchased and a cable like this was soldered (picture under the spoiler)

Noob version of the cable

Anyone who is in the know will immediately understand where I was wrong in making such a cable, and there are more than half of those reading this. I suspected something was wrong after I saw the krakozyabrs that my “orange” was spitting into the terminal. It was the understanding of the reason for my stupid mistake that prompted me to take the actions described below.

1. What is the difference between UART and RS232

The difference is in levels. The serial interface implemented in Orange Pi and other similar devices is based on TTL logic, that is, a zero bit corresponds to zero voltage level, and a one corresponds to +5 V. RS232 uses a higher voltage level, up to 15 V, and one corresponds to - 15 V, and zero +15 V. To increase the noise immunity of the channel, any voltage level below 3 V modulo is perceived as zero. The data transfer protocol based on a sequence of logical values ​​is absolutely the same for both UART and RS232. All this is illustrated by the following byte transfer diagram

How could I forget about this? When I was working at the electric locomotive research institute, I knew these things. And then for some reason he said something stupid. In general, it became clear that some kind of level converter with signal inversion was needed. The choice fell towards connecting the entire equipment to the COM port, which is on my motherboard home computer. Although of course you could look towards UART<->USB, because the old serial interface is steadily losing relevance. However, my tendency is to be more simple solutions won and this device popped up as a candidate for acquisition

Sold on the same “Ali” for 464 rubles. In principle, this could be found in stores or at the radio market in my city, but the itch to do something with my hands was already awakened. So I rejected the idea of ​​buying an interface board and decided to try making one myself.

I must say that I’m generally good friends with a soldering iron. At school and university, before buying my first computer, soldering all sorts of useful and not so nonsense was my main hobby. But I lived in a village, it was the nineties. There wasn’t much money; components were obtained by dismantling radio junk that came into view. The source of information was books from the regional library - not everyone had the Internet back then. There were no rich instruments either. Foil PCB and ferric chloride were a legendary miracle. In general it was difficult.

After buying a computer, all my passion switched to it. And the skill of soldering small amplifiers and receivers has been put on the shelf. So I'm a "teapot". Therefore, I ask you to be lenient about much of what I write below. And this article, by and large, is for dummies like me.

2. Selection of device circuit and its computer modeling

Finding a diagram of such a device on the Internet is a piece of cake. There are really a lot of such schemes. The choice fell on this decision

The heart of the entire device is a MAX232 type chip - a level converter operating on the “charge pump” principle. The voltage is increased from 5 V by alternately charging external capacitors C4 and C5. At the moment the signal is output to RS232, these capacitors are connected in series, and the voltage accumulated in them is added up. During reverse transmission, the microcircuit acts as a divider. In both directions of signal transmission, it is inverted.

Diode VD1 plays the role of “foolproof” - it closes the power circuit when voltage of the wrong polarity is applied.

Before starting to manufacture the device, I decided to see how it would all work, so I started by modeling the future device in the Proteus environment. A virtual stand was assembled to test the circuit

The first thing I wanted to do was to simulate everything, including the power circuits, since I was interested in the effect of the diode on the operation of the circuit. By default, in Proteus, the power pins on the microcircuits are hidden and pulled to the plus of the desired level and ground. To unblock them, you first need to show hidden pins. To do this, go to the menu Template -> Set Design Colors and check the box Show hidden pins

In which we check the Draw body and Draw Name checkboxes. After that, select the entire chip, including the text that labels the pins, and right-click the menu and select Make Device. We will be asked to choose a name for the new device and save it. That's it, after this the power circuits will be explicitly included in the simulation process.

Next, we will transmit something meaningful via UART, for example, the letter “A” encoded in ASCII with code 65 in the decimal number system or the sequence 01000001b in binary. In addition, to initiate a transfer, it is necessary to send a start bit with a level of “0”, and to complete the transfer, send one or two stop bits with a level of “1”. Thus, the timing diagram of a frame transmitted via UART will look like this

To generate such a signal, we use a source called Digital Pattern Generator (DPATTERN) with settings like

A pulse width of 104 microseconds corresponds to a speed of 9600 baud. The waveform is specified by a string pattern where "L" means low level and "F" means high level. Accordingly, our string will look like “FLFLLLLLFLF”. We will control the data received in RS232 using a virtual terminal, setting it up like this:

We will not use the parity bit, and will use one stop bit. In addition, let's say that the signal supplied to the terminal is inverted, which corresponds to the RS232 protocol. By starting the circuit simulation, we get an oscillogram of the signals and output to the virtual terminal

Channel A carries the output signal supplied to the COM port. Channel B is the TTL input signal. The treasured letter “A” is displayed in the terminal. Thus, we are convinced that the proposed scheme is fully operational. In theory.

3. Selection and purchase of components

Of the stores closest to where I live where you can get hold of radio components, there are two that deserve attention: the “Radio Components” store on Budenovsky Prospekt (this is the city of Rostov-on-Don) and the “1000 Radio Components” store on Nagibina Avenue, opposite the Rio shopping center. The latter is distinguished by the fact that it has a website, albeit quite ancient, and apparently lazily updated (and made on Joomla...). After crawling through the price list, I came up with a list of what I needed to buy.

I’ll say right away that I carefully avoided SMD components due to my inexperience. That's why I chose the MAX232CPE through-hole version. I took the same electrolytes and diode. However, it turned out that only the MAX232CWE chip was available - the same thing, only... SMD! After thinking for a second, I agreed with the seller’s proposal - we must start sometime... There were no 15 V capacitors, but there were 100 V capacitors of the same capacity and the same dimensions. Okay, that's okay too. Instead of a male DB-9 connector, I was offered a female connector. Thus the following list was obtained

Ferric chloride, tsapon varnish and textolite, of course, were not fully used. In addition, I did not include the purchased tool in this list: a simple soldering station (because before that I only had a 40-watt soldering iron with a copper tip), side cutters and small pliers, metal scissors for cutting PCB, liquid rosin-alcohol flux LTI-120 well and so on. In general, this epic cost me about 3,000 rubles.

IN general components were purchased and brought home. 40-pin PLS blocks were sawed off to accommodate the required number of contacts. One of the contacts is removed to ensure unambiguous connection. The hole in the socket block corresponding to the removed pin is sealed with polyethylene.

4. Assembling the device on a breadboard and checking operation

In principle, this is not necessary for such a simple device. But I’m a novice, so before making the board, I decided to test the circuit in real operation.

The most difficult thing was with the microcircuit. To solder it onto the breadboard, I had to mess around with soldering twelve legs to the copper conductors. A monster spider with twelve legs came out

At that moment, I realized two things: it’s good that I bought a soldering station after all. The bad thing is that I’ll have to tinker a lot with this little thing. In general, the components were soldered to a “breadboard”, the circuit was assembled with an “orange” board. +5 V power taken from the “orange” - 2nd pin on a double-row 40-pin pin block

To connect to the device it was used putty terminal, which is also available for Linux, and unlike minicom, has color output and does not require additional settings to enter characters into the terminal from the keyboard.

In general, the board started working - lines of the boot log ran across the terminal screen: first from u-boot and then from the linux kernel

Needless to say, how happy I was: firstly, the scheme works correctly, and secondly, Linux on the “orange” is installed correctly, it works normally in multi-user mode

The non-functioning HDMI connector and the lack of an Ethernet interface are therefore due to the configuration of the distribution itself. These problems, of course, will be solved and we are not talking about them here. Therefore, let's move on to the next point of the program

5. PCB layout

I made it in Altium Designer. It is better to do the board layout after the components have been purchased. Perhaps, as in my case, you will need to install additional component libraries for Altium. The dimensions of the components and the layout of the footprint for each must correspond to the actual parts available. Here I made an annoying mistake, but more on that below.

I will say right away - do not use automatic wiring. Perhaps this is configurable, but the auto-wiring tried to drag a path between the legs of the capacitors, which, with a distance of 2 mm between them, makes the path about a quarter of a millimeter wide, which was too steep for me as a “dummie”. And my intuition suggested that it was advisable to avoid such things. Therefore, I used manual routing (based on the results of the automatic one), setting the width of the roads to 0.5 mm in the routing rules (Design -> Rules -> Routing -> Width)

Additionally, by default Altium assumes the board is two-layer. To force him to route a single-sided board, in the wiring rules you should specify the wiring in one layer, say in Top Layer

The circuit was typed in the circuit editor

In this case, it is necessary to take into account the fact that the free unsoldered inputs of the microcircuit (legs 8 and 10) must be pulled to the ground, otherwise Altium will not compile the circuit to transfer it to the board editor.

As a result, by independently tinkering with the program and lessons from Alexey Sabunin the goal was achieved and the payment was made

All components mounted in holes are located on the clean side of the PCB, and the microcircuit, due to the SMD design, is located on the side of the tracks. To print the circuit layout, you need to create a so-called Output Job File in the device project

Which is configured as follows. In the list of configuration options, select Documentation Output and click on Add New Documentation Output, selecting PCB Prints and the board project related to our device from the menu that appears.

We rename the documentation item that appears, let's call it LUT, for transliteration technology (LUT), which we are going to use to transfer the board design to copper. Right-click on the LUT and select Configure from the context menu. In the settings of the layers to be printed, leave only two items: Top Layer and Multi-layer and check the boxes as shown in the screenshot

The Mirror checkbox is needed in particular for mirroring drawing on the print. This is important, otherwise when transferring the drawing to copper it will turn out mirror reflection our paths, but we don’t need it. Also, you should look into Page Setup

To select the paper size and pay attention to the scale factor (Scale). When first printing it turned out to be equal to 1.36 for some reason, but should be equal to one

Now click Print. I don't have my own printer, so I printed it to PDF using Foxit Reader, and then took the resulting file on a flash drive to the sharashka nearest to me, where I printed the drawing on glossy photo paper. In the end it turned out like this

The size of the board was 62 x 39 mm; a piece of PCB was cut to this size using metal scissors. Previously, I sawed textolite with a hacksaw and often (or rather always) it turned out terrible. With scissors it comes out smoothly, without debris or damage to the conductive layer.

6. Printed circuit board manufacturing

The LUT (laser ironing technology) method was chosen because of its simplicity and accessibility. Served as a guide to action. I tried not to violate the technology: I went over the copper with a zero point, degreased it, though not with acetone, because I couldn’t find where to buy it, but with a universal degreaser based on white spirit, bought at Lerua Merlin. Carefully and with effort I ironed the sandwich made of PCB and pattern with an iron at maximum temperature. Either because I made a mistake somewhere, or because I didn’t let the workpiece cool down, or they were simply saving toner on the printer in the “sharashka”, in general it didn’t turn out very well

However, I wisely stocked up on an Edding 404 permanent marker, with which, with the help of my beloved wife (with her advanced skill in lining eyelashes and drawing patterns on nails), I outlined all the paths

Next, a solution of 6-aqueous ferric chloride was diluted at the rate of about 180 grams per 300 ml of water (water was taken from the tap, hot) and the board was thrown into the etching cuvette to be eaten. In order to etch the board without poisoning his wife, the operation was performed at sunset on the balcony

“Khlonyak” did not disappoint, there are rumors that they often sell low-quality ones. The etching took 13 minutes, the last islands of copper were disappearing right before our eyes. The main thing is not to forget to periodically kick the board with tweezers on the cuvette and monitor the process. As soon as the excess copper disappears, we urgently take out the board and rinse it with a copious stream of water.

After washing, wiping and drying, the moment of truth comes. The protective covering must be removed. I tried to do it with white spirit,

But things were going badly. Then my wife offered her nail polish remover - this miracle elixir removed the coating instantly (I am still horrified by the reagents our women use. Beauty is a terrible power!)

The marker did not disappoint either - all the paths survived

After cleaning the protective coating, you can start drilling holes. And here I made an unfortunate mistake - I didn’t have a 0.5 mm drill, and instead of postponing the matter until tomorrow, having bought the necessary drill, I rushed and took a millimeter one, thinking that it would do. As a result, I damaged many contact pads, fortunately not badly and not irreversibly. But still, never rush. As my friend Mark from the laboratory of the Department of Mechatronics at the University of Munich, where I did my pre-graduation internship, said, “Dmitry, take the right tool for every job.” And he was right a thousand times over.

7. Tinning the board and soldering components

Places where components are soldered should be covered with a thin, shiny layer of solder. This is the main condition for successful work. I didn't tin the entire tracks. Firstly, I was afraid of warping them, and secondly, I was still going to cover the board with varnish. So I only tinned the solder joints. To do this, apply rosin-alcohol flux LTI-120 to them with a brush and use a soldering iron heated to 250-300 degrees, from the tip of which a tiny drop of solder hangs, draw it along the desired points of the board. Due to the increase in surface tension by flux, the solder spreads over exactly the contact pads.

After this, the “breadboard” was disassembled, the wiring was removed from the microcircuit, and it was soldered first. Using your hands or tweezers, carefully place the microcircuit in its place in accordance with the pinout, so that each leg occupies its own area. Then we lubricate the rows of legs with flux. Using short and precise movements, we touch all the legs in turn, not forgetting to put solder on the soldering iron tip (but not too much, a small drop is enough). If everything is done correctly, then the legs are soldered to the pad very quickly and accurately, without “snot” or bridging neighbors. It took me less than a minute to solder the chip, and this is my first time doing this. Inspired me to do this feat this video, for which I am very grateful to its author. Everything turned out to be really not so scary.

I figured out the rest of the details in a similar way. The main thing here is to carefully cut the leads of the parts to the required length - I left no more than a millimeter of the lead sticking out above the track, and bend them correctly and carefully if required. It is important, extremely important not to rush anywhere and do everything thoughtfully. In the end, what happened is what happened

I couldn’t get away from the “snot”, but for the first time it turned out pretty tolerable, although I’ll probably be criticized.

8. Checking circuits and another annoying mistake

After soldering, we wash off all the flux with alcohol, pick up a multimeter and call all the circuits to check their conductivity and compliance schematic diagram. And here the bad thing crept up unnoticed. The COM port connector turned out to be wired in a mirror way! “Earth” sat on the first leg instead of the fifth, Rx on the fourth instead of the second. And I still don’t understand how, because when wiring in Altium everything was correct. This remains a mystery to me. There is no mystery - simply having in fact a “female” connector, when forming the circuit in Altium, I still used the “male”. Hence the mirror wiring that resulted. Fortunately, I solved this problem by appropriately wiring the cable intended for connecting the device to the COM port of the computer. But because of this COM errors on the board it turned out to be so “proprietary”.

Otherwise, the installation turned out to be correct and I, having unsoldered the connecting cables and tidied up workplace, connected the new board to the “orange” and the computer

The download log lines ran across the terminal window again. I was happy!

9. Bringing beauty

In order to protect the contacts from oxidation and give the device an “industrial” look, the board was painted with green capon varnish. All marks made before installation with a permanent marker were washed off with this same varnish. Oh well... Here is a photo of the finished product along with a set of cables

Now we can begin to further refine the software for the “orange”. Now I won’t be blind and dumb, but will be able to set up the system through a serial terminal.

Conclusion

It was interesting. It’s interesting for me because it’s the first time. The first device designed on a computer and assembled on printed circuit board with your own hands. And if someone smiles ironically, then let him remember that he, too, once did this for the first time... Add tags

(ArticleToC: enabled=yes)

The small-sized USB TTL PL 2303 adapter is a kind of programmer used with a board to read information from various sensors:

• humidity;
• temperature;
• movements.

This is the reason for the widespread use of the USB TTL PL2303 adapter in radio-controlled devices. The TTL USB adapter is programmed in C++, i.e. The USB TTL adapter is a "universal bus" for data transfer used in low and medium speed computing technology.

To connect it to the USB RS232 TTL adapter you need a four-wire cable. One twisted pair is needed for differential connection during reception and transmission (RX and TX), and the remaining ones are needed to supply power to peripheral devices (GND and +5V).

Provided that the maximum current of such devices does not exceed 500mA, and for USB - 900mA), they are connected without their own power source.

Despite the fact that for TTL logic 0-5 V are available standard levels, it seems like a TTL USB adapter is not needed.

But, due to the fact that the USB interface/protocol is quite complex, building a device based on it requires deep knowledge and microprocessors that process the data.

Another protocol can be used to help - UART (UART), which is the most common today. Among the family of many protocols, the most commonly used is RS-232, commonly referred to as the COM port. It is the oldest of all, but still relevant today.

It has lines:

• transmitting - TXD;
• host - RXD.

If they are used to transmit data, then there is no need for hardware control. For hardware, DTS and RTS are used.

The transmitter output is connected to the receiver input and vice versa.

RS-232 differs from standard (5-volt) logic electrical principle actions. In this version, “0” lies in the range of +3 to +12 V, respectively, one is in the range from -3 to -12.

Conclusion. The purpose of UART USB TTL adapters is to “join” a complex interface

USB with a simple and “running” UART protocol, supported by microcontrollers, and working with logic levels 0-5V.

The USB RS232 TTL Pl 2303 adapter is assembled on a PL2303 chip, which creates a virtual COM port on a PC. Used for flashing devices with microcontrollers.

Its cost is 40.84 rubles.

To deliver to Ukraine you need to pay an additional 149.74 rubles.

Main Features of PL2303 USB to TTL Module Adapter Converter:

• voltage type – regular;
• power supply – 3.3/5 V;
• purpose - for computer;
• temperature range - -40 TO +85;
• Manufacturer: Diymore.

USB 3.3V 5.5V to TTL Mini Port Adapter

Review

• Size – 36x17.5 mm (LxW);
• Pins: GND, CTS, VCC, TXD, DTR, RXD, RXD;
• Chipset FT232RL;
• Supports – 5V, 3.3V;
• Pitch – 2.54 mm.

Excellent quality modules costing 100.24 rubles. offered by online store https://ru.aliexpress.com/popular/ttl-adapter.html .

To detect a car using GPS adapter USB TTL PL2303 HX RS232 converter

Its cost is 42.7 rubles.

Features include:

• antistatic packaging that prevents the accumulation of static electricity,
• negatively affecting work;
• high reliability, stability;
• WIN7 support.

A product weighing 5 grams (without packaging) is used in student production experiments, etc. Its size is 50X15X7 mm. For converters of the USB PL2303 - RS232 model

TL has a pair of interfaces that serve to connect (five-pin male) and PC (USB standard).

FT232RL USB 3.3V 5.5V to TTL mini port

Its cost is 106.43 rubles. This is an inexpensive option to increase the possibility USB microcontrollers. For protection, a 500ma self-resetting fuse to protect against current overloads.

Characteristics

• color – red;
• power supply USB-5 or 3.3 V;
• weight – 4 grams;
• dimensions - 43x17 mm.

Its small size makes it possible to use it in developments where the size of the gadget is critical.

USB to TTL to UART on PL2303 chip

Used for Arduino programming.

The converter on the Max3232 chip converts RS-232 port signals into ones suitable for use in digital circuits based on TTL technologies.

Costs 76.11 rubles.

CP2102 USB 2.0 to TTL UART 6Pin

Consists of CP2102 board, USB2.0 full-speed built-in, crystal oscillator, UART data bus and supports signals without requiring external USB modem

• Weighs 4 grams;
• LED indicators for: power, transmit and receive;
• Working status – 3.3 and 5 V.

Costs 82.3 rubles.

Almost all microcontrollers have on board serial port — UART. It works using a standard serial protocol, which means it can be connected to a computer without any problems. COM port. But there is one problem here - the fact is that the computer RS232 it takes for logical levels +/- 12 volt, and UART operates at five-volt levels. How to combine them? For this, there are several options for level converter circuits, but the most popular one is still based on a special converter RS232-TTL. This is a microcircuit MAX232 and its analogues.
Almost every company makes its own converter, so this will also work ST232, And ADM232, And HIN232. The circuit is as simple as three kopecks - input, output, power supply and a circuit of five capacitors. Capacitors are usually placed 1uF electrolytes, but in some modifications it is installed 0.1uF ceramics. I soldered everywhere 0.1uF ceramics and usually that was enough. :) Works like a clock. If on high speeds will fail, then you will need to increase the capacity.

By the way, there is also MAX3232 this is the same thing, but its output is not 5 volt TTL, but 3.3 volt TTL. It is used for low-voltage controllers.

I made myself one such universal cord so that it would be convenient to cling to the controllers. UART. For overall compactness, I stuffed the entire circuit directly into the connector, fortunately I had ST232 in soic corpus. The result was a scarf no larger than a ruble coin. Since there were no small SMD capacitors at hand, I had to solder the capacitors from above, whatever the cost. The main thing is that it works, although it didn’t turn out very nicely.

If you doubt that you will succeed in such a small installation, then I wired the board for you to a standard PDIP case. It will be the size of a matchbox, but there is no need to chop it.

After assembly it is easy to check:
Plugs into connector COM port. Apply 5 volts of power to the circuit and then close Rx on Tx(for me these are green and yellow wires).

Then you open any terminal, at least Hyper Terminal, you connect to the port and start sending bytes, they should immediately come back. If this does not happen, check the diagram, there is a jamb somewhere.

If it works, then everything else is simple. The wire that comes from pin 9 of the microcircuit MAX232 This transmit pin, put him on your foot RxD controller. And the one with legs 10 - receiving, feel free to put him in custody TxD controller.

Some Maisku readers probably remember my review of a homemade laboratory power supply. Recently, interface converters came to catch up with it to connect it to a computer.

I ordered them noticeably later than the boards, and they took a long time, so they arrived when I had almost finished everything.
The scarves are cheap, there were more than one, but I will review their company later (if I can come up with a theme and use). The seller gave the left track to some Chinese fake website for tracking (however, he warned about this), but since the parcel is inexpensive, he was not particularly worried, he just kept an eye on the deadline for delivery of the order.
But everything arrived in perfect order, in a white envelope, packed in neat bags with a latch.

There was even some kind of sticker on the bags with a number, apparently an article number or something else, but in general this is unimportant, but I gave it to the seller for neatness - excellent.

The interface converter is assembled on the very common PL2303 manufactured by prolific, this is of course not my favorite FT232, but in principle it is quite tolerable, since I have never come across genuine FTDI microcircuits for reasonable money, and these cards cost mere pennies (especially considering , that in our market they cost 2-3 times more). Yes, there are even more “tasty” prices for these boards, but I didn’t need 10-50 pieces, so I took it that way.

The board has 3 LEDs, red for power, blue for transmitting and green for receiving.
Either the resistors are chosen incorrectly, or something else, but the red shines so much that your eyes pop out, the blue shines weakly, and the green is barely visible at all. But since these LEDs had no meaning at all for me, I did not bother to deal with them.
There is also a 5-pin connector installed on the board, to which 3.3 Volts, 5 Volts (as I understand, actually directly from USB), RX, TX and General are output.
The fee is collected according to the most the simplest scheme, 3.3 Volt output is taken from PL2303, RX is pulled up to 5 Volts, TX outputs a log level with a voltage of 5 Volts.
If you need to output other signals, you will have to suffer.
All denominations installed parts signed on the board, assembled quite neatly.

But as I wrote above, I didn’t need the boards to admire colored LEDs, so I decided to immediately use them, at least one, the second one will be for some other crafts.

I prepared everything necessary for finishing these boards and got down to business; in the process I will note some features of these boards.

I decided to use the converter board in my laboratory power supply, which I recently posted a review on. By the way, this card (galvanic isolation board) is present on the common trace with the front panel.

The actual application.

To do this, I assembled a small adapter board, on which I installed an optical isolation chip for the interface; since the speed is low, I bought the cheapest ADUM1201A.

Yes, you could, of course, try to make optocouplers using optocouplers, but given the price of the microcircuit a little more than a dollar, I didn’t really want to, maybe I was just lazy.
This chip allows you to make galvanic isolation of the interface at speeds of up to 10 Mbit (there are more high-speed versions, differ by letter)

The board is “dressed” in soft transparent heat shrink, but since for my application it was a little in the way, I decided to shorten it a little.

I also didn’t really need the connector that was installed on the board, since I find this type of connection rather inconvenient when the board is plugged directly into USB, but it depends on who. The connector was soldered quite easily, I didn’t even have to turn on the hairdryer, I made do with a regular soldering iron since the fastening tabs of the connector were not soldered, for those who will use a scarf with this connector, I would recommend soldering them.

At the same time, I also unsoldered the output connector; Ground, Receive, Transmit, Output 5 Volts, Output 3.3 Volts are output to it.
All contacts are labeled on the board itself and correspond to the inscriptions.
I needed the connector itself, but it was a little different from the one that comes with the board, so I had to bend it.
At the same time, I shortened the board, since it didn’t want to fit in the full version, and there was nothing on the cut piece. This is the kind of doping, although it’s more like peeling. :)

View from a different angle, probably everyone has already guessed why I did such manipulations with the connector.

I soldered the cable to the back panel, I thought it was better to do this before assembling the two boards into one construct. I used the simplest cable, 4x0.22 in the screen, although at such a distance it would probably work even through a rope.

I soldered a USB connector on the back side, secured the cable with ties and prepared a pair of fastening “ears” from scraps of foil PCB (I even remembered my youth when I made small cases from fiberglass by soldering cut out plates together).

I soldered the plates to the connector, the most difficult thing was to solder them evenly, otherwise they might break off when screwing them on.

I cut a hole in the power supply housing, drilled holes in the mounting lugs and cut M3 threads into them (who doesn’t know, fiberglass makes a pretty good thread, you don’t even need any nuts).

I installed this entire structure in its regular place, and it became as if it had always been there.
The photo shows that the board would not fit at its full length. However, I didn’t even measure it, it was already obvious from the very beginning.

A little closer.

Attentive readers will notice a small scarf and a suppressor, which were not in the photos in the review. These are the consequences of my experiments with MAX232. When connecting the MAX, I mixed up the 1st and 2nd legs of the microcircuit with 15 and 16, overloaded the PWM logic power supply stabilizer and the op-amp, and it released magical smoke with a beautiful fireworks display.
In a second the PWM itself burned out, burning through, 3 operational amplifier and indicator. The processor remained alive. Thanks to this (it would not have been luck, but misfortune helped) I remade the power stabilizer, replacing it with a better LM5007 (input range up to 75 Volts, output current up to 500mA), and figured out the principle of calibrating this board (I generally found this information on the Internet did not met). Calibration information has been added to the PSU review.
The native PWM did not have overload protection (there was no short circuit), which is very sad.

Due to my small miscalculation, I had to install the connector on the rear panel “upside down”, literally.

All this is of course good, but I would like to check what I soldered at all. I connected it to the computer and started trying. But I immediately received a big worldwide bummer. The software worked, but since the software is from version 6010, I received control with a shift of 1 sign. The 6010 board has a minimum current setting discrete of 10mA, the 6005 board has 1mA, respectively, I set it to 1 Ampere, and received 100mA.
Naturally, this state of affairs could not suit me in any way and I went to the Internet.
I found software for version 6005 from some Chinese electronics engineer (or an advanced seller). I removed the old one, installed the new one, and finally got what I wanted from the very beginning. Normal board control.

This has reached the logical conclusion of the epic with the laboratory power supply, which includes three (although formally four) reviews.
What I got in the end -

Converter Board Overview -

Summary.
Pros.
The boards work perfectly, no defects were found
The seller sent everything clearly and on time.
Everything arrived in excellent condition.
The scarves cost me cheaper than on the market.

Minuses.
LEDs have different brightnesses, it didn’t matter to me.
The fastening tabs of the connector are not soldered, but this even helped me.

I hope that this review will help save some money for those looking for similar boards.