On-board computer in an old car. DIY on-board computer

Any digital device seemed like a computer to us - even a primitive tachometer with two numbers. How many computers are installed in an average car today? Things are already approaching a hundred... Moreover, the capabilities of a modern smartphone significantly exceed the potential of the computer on the Curiosity rover, which is only five years old.

What can't standard on-board computers do? Bend your fingers. They will never tell you error codes for engine, automatic transmission, door or window control systems. They rarely show engine temperature, average speed, travel time or acceleration dynamics to hundreds, and also do not like to remember errors that occur. In addition, many drivers need hazard warning lights that monitor temperature, engine speed, and speed.

The owners have their own requests - to take at least the fuel consumption of two types. Some people need automatic turning on of headlights based on a signal from a speed sensor or connection of parking sensors with adjustable sensitivity. In some cases, it may be useful to force the cooling fan on. Some people want to more accurately adjust the fuel level sensor in the tank. Various reminders will help those who are forgetful - warning about the side lights not being turned off, about ice on the road, or the need to undergo regular maintenance. Many people love simple talking toys (“Hello, master!”). Extreme enthusiasts may need a wheel slip indicator. And there is also such a function as a taximeter...

We decided to test ones suitable for budget cars. The capabilities of the devices selected for the study are different, but all the more interesting.

• trip parameters: travel time, mileage, current and average speed, instantaneous and average consumption, remaining fuel in the tank, ambient temperature, cost of the trip;
• current engine operating parameters: pressure in the intake manifold, fuel pressure in the line, injection duration, air pressure at the compressor outlet, mass air flow, oxygen sensor voltage, crankshaft speed, throttle position, gas pedal position, instantaneous fuel consumption, calculated engine load, coolant temperature;
• error parameters: ECU errors, reset and error recording;
• parking parameters (some devices turn their screen into a display of full-fledged parking sensors).

And most devices also provide a voice warning when the controlled parameters leave the specified range.

It seemed to us that the most interesting option in the presented computer company was the Multitronics MPC‑800. Mainly because such a device, which has decent “brains,” does not disfigure the interior of the car, since it is hidden somewhere inside, assigning “representative” functions to the owner’s smartphone. For many, this may be the deciding factor when choosing a device.

The on-board car computer or the “brains” of the car is the most important element for controlling and monitoring the performance of all the main components of the vehicle. BC is installed on all modern cars today. You can learn more about the principle of operation and types from this material.

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Description of the on-board computer

What is an on-board computer in a car and what tasks does it perform? First, let's look at some theoretical points. The BC is an electronic unit that allows you to react and control various processes in the operation of different car systems. That is, thanks to the BC, the driver will always be able to receive data on the operation of certain components. We figured out what an on-board computer is, now we’ll tell you about its purpose.

What the on-board computer shows:

• the device demonstrates gasoline consumption in different driving modes;
• allows you to control the injectors, as well as the vehicle ignition system;
• monitors the operation of the transmission;
• can control various additional systems via two-way communication, for example, a rear view camera, etc.;
• allows you to determine the level of engine fluid pressure and antifreeze temperature;
• regulates the voltage level in the car’s electrical circuit, monitors the battery charge;
• if the vehicle is equipped with a climate control system, then the BC controls it;
• One of the main options - the on-board computer for the car allows, if necessary, to read error codes and show them on the display so that the driver can decipher them and find out where to look for a breakdown.

Principle of operation

The principle of operation of an automobile BC for carburetor engines or injection options is not particularly complicated. The device is connected to a chain of controllers and regulators, reads the necessary data, and then processes the received information. Special software is used for processing. For example, if the BC receives data on fuel consumption according to the scheme, then the software will allow you to calculate the possible mileage with the remaining amount of gasoline.

All data is displayed on a screen installed in the vehicle interior. The display itself can be digital, monochrome, color, or four or three digits. As practice shows, a 2-inch diagonal monochrome screen is quite enough to show the driver more than ten parameters. More modern versions of bookmakers today are equipped with a high-precision liquid crystal screen.

Kinds

Today there are several types of BC:

1. Universal option Such a device combines various options and gives the car owner the opportunity not only to drive the car, but also to surf the Internet. The main purpose of such a device is to increase comfort for the car owner while driving. Typically, a universal on-board computer has a screen with a diagonal of 6-14 inches; newer models can be connected to a keyboard. It should be noted that in their design, such BCs are very similar to ordinary computer PCs, but one of the features of the devices is the low degree of integration with the car’s electrical system.
2. Route. The trip on-board computer allows you to determine the driving parameters of the car, and it does not have to be connected via GPS to the satellite. However, newer models are equipped with GPS receivers in any case. Using such a device, the driver will be able to determine the average speed of the car, fuel consumption, remaining distance to a particular point, mileage traveled, etc. In addition, depending on the model that you install in your car, the device may have a function for calculating fuel consumption during emergency braking or rapid acceleration. Typically, BCs of this type are installed in the control panel.
3. Manager and service bookmaker. The purpose of such computers is to detect breakdowns of the main components of the vehicle and warn the car owner about this. As a rule, such a BC is an integral part of the machine control system, but depending on the model, it can also be an independent device with extensive functionality. When checking a car, all combinations of errors are stored in the device’s memory and will remain there until the error is corrected and the memory is reset (the author of the video is the AvtoGSM channel).

Bookmaker setup

Making an on-board computer with your own hands is a difficult task to accomplish at home. To make a device, you will need many different elements, including a display, a chip, buttons, etc. It is impossible to make a computer on your own without experience in assembling such devices, so if you want the device to work correctly, then it is better to order this procedure or buy a new computer.

If you decide to install an on-board computer for carburetor or injection engines on your car, then you need to know how to configure the device correctly:

1. If necessary, you can always activate the automatic configuration option - then the device itself will accept the necessary configuration.
2. If this option does not suit you, then go to the settings menu - find the desired block and select it. It should be noted that in this case the bookmaker must be configured as the main device. One of the important roles in setting is determined by the choice of mode, thanks to which fuel costs will be recorded.
3. When setting this parameter, you have several options. One of them is a linear dependence, in which case the parameter will always depend on the control unit. If you decide to configure it manually, then first you will need to make a table on fuel consumption. Taking this information into account, the bookmaker will carry out calculations and display the corresponding parameters on the screen.
4. In addition, you will need to determine the parameters that the screen will begin to display; depending on the model, their number may vary. Separately, we should highlight the parameter responsible for the activation temperature of the engine cooling fan.

Price issue

The minimum cost of a bookmaker from the Multitronics company will be around 130 rubles. More expensive options can cost 7,500 rubles.

Sorry, there are no surveys available at this time.

Video “How to make a bookmaker with your own hands”

Detailed instructions for making the circuit are presented in the video (author - channel libral1973).

Modern cars are increasingly equipped with an on-board computer for recording instantaneous and average consumption. Being the owner of a Fiat Marea 1.9JTD, this function was not provided for. Factory devices refused to work or displayed scant and unimportant information.

I am a supporter of simplicity and reliability of my developments. This is completely demonstrated by the operation of the assembled device.

Homemade on-board computer (BC) via the K-Line interface for Italian cars. Tested for JTD Euro 2 and 3 (CF2, CF3). The circuit for matching the levels of the microcontroller with the K-line was taken from the ELM327 diagnostic adapter; commands (PIDs) for polling the car ECU were scanned along the K-line when running the Multiecuscan diagnostic software. We also studied the documentation [ JSC AvtoVAZ General Development Department Electronics and Electrical Equipment Design Department], [ISO/WD 14230-1 - Road Vehicles - Diagnostic Systems - Keyword Protocol 2000 - Physical layer].
ISO14230 protocol. To receive/transmit via the K-line, the PIC16F628 hardware USART interface was used. But since the transmitter pin (TX) does not have the function of the inverse operating mode required by the circuit conditions, the adjacent pin was used. Which operates programmatically in the TX transmitter mode, inverting its state.
The circuit is based on a 16x2 HD44780 indicator (power pinout may differ), a PIC16F628A controller and some passive smd elements (size 1206 and 805), the rating is not critical. Transistors can be MMBT2222 SOT-23 (2N2222). Krenka for 5V in the layout with the heatsink up for a circuit with a dip PIC. Depending on the LSD backlight (>20mA), a small heatsink may be required for cranking. Chain R10 and D16 perform the protective function of the circuit. The board itself fits into the dimensions and is glued to the back of the display.

When connecting the circuit to a car, connect the K-line last, do not allow the K-line of the BC to be shorted to positive!

The software part of the circuit begins with initializing the LCD and connecting to the car's ECU. For Euro type ECUs 2 and 3, the addressing of connection to the unit is different; the selection is made by holding the UP button until the desired type CF2 or CF3 appears. If the connection to the ECU is successful, the LCD backlight will turn on. Next, read the HW and SW numbers of the ECU for JTD. And go to the first menu, 4 parameters (instantaneous and average flow rate, engine speed and temperature), other menus can have 2 or 3 parameters. Jump by
menu with the UP or Down key (press indication is the first segment shaded). You can save the current menu (from 0 to 12) as the starting menu when you turn on the on-board computer - by holding UP for a long time (more than 2 seconds).

In menu 13 - reading errors, displaying the number of errors and up to 4 codes (P*** together), deleting errors - by holding UP for a long time.
In 14 menus (instantaneous consumption and total amount of gas oil) - you can change the number of cylinders in the car (4 or 5) to correctly calculate fuel consumption - by holding UP for a long time.
In menu 15, reset the average speed and average flow, and also adjust the LCD backlight - by holding UP for a long time.
LCD backlight control is a chain: pin13 through T2 - standard brightness; and pin3 through R12 - reduced backlight brightness.

In the update of the circuit, archive No. 2, the menus are shifted and 15 menus are allocated for continuously adjusting the brightness of the screen backlight (PWM). When you hold the button for a long time, the brightness increases smoothly from 0 to 255 and so on in a circle. When the button is released, the brightness value is saved in non-volatile memory. In this case, it is possible to lose communication with the ECU, because the poll is interrupted.
Fuel consumption is calculated based on the readings of the total amount of gas oil, revolutions and speed of the car. And the calculation occurs when the consumption menu is active. Instantaneous consumption is displayed in liters/hour at speeds up to 10 km/h, and above - in liters per 100 km. By de-energizing the BC, the average flow rate is reset and =0. Formula for calculating consumption =...Liters*100/...km. When the distance traveled is zero, the average consumption tends to infinity. As you move and the distance traveled increases, the average will approach the instantaneous flow rate.
The menu includes a set of the following parameters: engine speed, current speed, cruise control speed, engine temperature, fuel and air temperature, heating of glow plugs and fuel, total amount of gas oil, air consumption, fuel pressure and its regulator, boost pressure and its regulator; calculation of instantaneous and average flow rate, and average speed; read/delete auto errors.

The message "Error K-Lines" indicates that the K-line is shorted to negative, the circuit power is below 9V, or the circuit is faulty, in particular, transistor T1 burnt out when the K-line is shorted to positive.
In the VAZ version, all data is read directly from the ECU in one frame, including consumption in l/100 km and l/h, according to the documentation. For VAZ (Lada) BC works with the January-... block.

List of radioelements

Technology does not stand still and today car enthusiasts are offered many different options for improving their “iron horses”. One of these is Arduino. This device is a tool used for designing electronic devices. In the case of a car, the design is usually done on the windshield. How to make an on-board computer using Arduino and how to configure it correctly - read this article.

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Ideas for a car based on a small board with a small processor - Arduino

Computers have long been a part of our lives. The Arduino hardware platform is one of the latest open source developments that is built on a conventional printed circuit. We will tell you more about how to make different devices for cars using such a board.

BC

Using an Arduino board, you can build a car on-board computer that can:

• calculate fuel consumption;
• display information about the antifreeze temperature;
• calculate the speed of movement, as well as the distance of the trip;
• remove spent fuel over a certain mileage;
• determine the motor speed, etc. (the author of the video is the Arduino Tech PTZ channel).

In addition to the Arduino device, you will also need an LCD module, a Bluetooth adapter NS-05, as well as an ELM327 scanner and a 10 kOhm resistor device. Of course, it is necessary to prepare the sound indicator, installation wires and the device body itself.

The assembly procedure is as follows:

1. First we set up the Bluetooth adapter. You need to solder wires to the pins of the device - to the two lower and upper contacts.
2. The module itself is connected to the board for configuration; to do this, you need to open the Arduino IDE 1.0.6 program or any other version, then upload the sketch to the circuit via the USB output.
3. When the download is complete, you need to go to the Tools menu - Port Monitor and set the speed to 9600.
4. Then a circuit is assembled with a board, an adapter and a pre-prepared display. First, connect the Bluetooth adapter.
5. After this, a display is added to the circuit. You will find a more detailed description of the connection in the photo below.
6. A 10K resistor element is used to control the brightness and contrast of the display. Therefore, when you first connect, you may notice that there is no image, if this is the case, then you just need to adjust it by turning the resistor.
7. Next, an additional key is connected, which will perform the function of switching screens with information. One contact from the button goes to the GND element, the second to pin 10. To connect the beeper, the positive contact is connected to pin 13, and the negative contact to GND.
8. Then, using the same Arduino IDE 1.0.6 software, you need to upload the sketch. Now all you have to do is set up the on-board computer and connect it to the car.

Photo gallery “BC connection diagram”

GPS tracker

To build an Arduino-based GPS tracker, you will need:

• the board itself, the process is described using the example of the Mega 2560 model;
• GSM/GPRS module, which will be used to transfer data to the server;
• as well as an Arduino GPS receiver, in the example we will look at the SKM53 model (the author of the video about making a tracker using the SIM 808 board as an example - Alex Vas channel).

How to connect the circuit:

1. First, the module is connected to the main board; the default baud rate is 115200.
2. After connecting, you need to turn on the device and set the same speed for all ports - both serial and software.
3. The GSM transmitter is connected to pins 7 and 8 on the main chip.
4. Then the module is configured by entering commands. We will not describe all the commands; they can be found on the Internet without any problems. Let's consider only the most basic ones. AT+SAPBR=3,1, “CONTYPE”, “GPRS” - the command determines the connection type, in this case it is GPRS. AT+SAPBR=3,1,“APN”,“internet.***.ru”, where *** is the address of the mobile network operator that will be used. AT+HTTPINIT - this command initializes HTTP.
5. One nuance should be noted - when writing the server component of the interface, it is advisable to provide for receiving and outputting data for several adapters. You need to set the switch to three positions, this will make it possible to receive data from eight cars.
6. Then the sketch is written on the microcircuit. The sketch itself can also be found on the Internet; it is not necessary to write it. Please note that if two active serial ports are used, this may lead to errors in the transmission and sending of information.

Parktronic

To build a parking sensor, you will need the following components:

• the chip itself;
• ultrasonic device, in this case it is the HC-SR04 rangefinder:
• six LED elements;
• six resistor elements with a resistance of 220 Ohms;
• male-to-male connecting wires;
• piezodynamic element;
• layout diagram for assembly.

The build procedure is as follows:

1. To begin with, you need to install LED elements prepared in advance on the breadboard circuit. The negative contact of all LEDs will be common. The short contact - the cathode - should be connected to the negative bus, which is located on the breadboard.
2. To the longer contacts of the diodes, that is, the anodes, you need to connect 200 Ohm resistor elements; if you do not use them, this will lead to the diodes burning out.
3. An ultrasonic device is installed on the central part. There are four pins on this controller. Vcc is the five volt power pin, Echo is the output pin, Trig is the input, and GND is ground.
4. After the rangefinder is installed, wiring should be connected to its outputs. In particular, the Echo pin is connected to output 13, Trig - to pin 12. GND, accordingly, must be connected to ground, which is available on the controller circuit, and the remaining Vcc output is connected to the 5-volt power supply on the Arduino board.
5. After completing these steps, you need to connect the wiring to the contacts of the resistor elements. They are also connected in series to pins on the board - pins 2 to 7 are used.
6. The next step will be to connect a piezo beeper, which will warn the driver when approaching an obstacle. The negative output, as an option, can be combined with the negative contact of a previously installed rangefinder. As for the positive contact, it connects to pin number 11 on the chip.
7. In order for the device to ultimately operate in normal mode, you will additionally need to write and then load the program code into the board. In this code, it is necessary to accurately indicate the distance, when approaching which the diode elements will light up and the buzzer will be activated. Moreover, the tone of the beeper should be different so that the driver can know when approaching an obstacle will be critical. The code itself is either written independently, or a ready-made version is taken from the Internet. There are a lot of sketch options, you just need to choose the most suitable one for your device (the author of the video is the Arduino Prom channel).

Conclusion

As you can see, the Arduino microboard is a universal option with which you can create many different devices. In addition to the devices described above, you can also build a speedometer that will display speed information directly on the windshield, a start-stop button, and even an alarm for the vehicle. In general, there are a lot of options, if you approach the issue of making a homemade gadget correctly, then you will succeed.

Of course, to do this you must have knowledge in the field of electronics and electrical engineering, while minimal skills will most likely not be enough. When making devices, you will have to make your own decisions, which may not be available on the Internet. Therefore, be prepared that the assembly process may take quite a long time.

Video “How to build a control system for an electric stove motor?”

From the video below you can learn how to set up climate control by modifying the heating system regulator using the example of a VAZ 2115 car (the author of the video is Ivan Nikulshin).

On-board computer for a car- , printed circuit board and microcontroller program are available. A rain sensor is assembled on a single-sided printed circuit board made of foil fiberglass, shown in Fig. 5. As can be seen in the photograph Fig. 6, the terminals of trimming resistors R28 and R29 are bent at an angle of 90° so that the resistors themselves are installed with wide edges parallel to the surface of the board and mainly outside its contour. Since the six-pin X7 connector could not fit between the trimming resistors, it is divided into two parts: a four-pin one installed on the board (pins 3-6) and a two-pin one suspended on the connecting wires (pins 1 and 2, connected to the heating circuit R30R31).

The emitting diode and photodiode of each pair are tilted towards each other so that their longitudinal axes - the directions of maximum radiation and sensitivity - intersect exactly on the outer surface of the windshield, forming a right angle. To achieve this, the tilt of the diodes is selected when installing the sensor on the glass or the thickness of the adhesive gasket between the body and the glass is changed.

rice 7 (1,2)

Fig 8 (1.2)

A drawing of the main double-sided printed circuit board BC made of foiled fiberglass laminate 1.5 mm thick is shown in Fig. 7, and the location of the parts on it is shown in Fig. 8. This board is designed to install fixed resistors and capacitors, mainly of size 0805 for surface mounting. Resistors R3 and R36 are ordinary MLT, C2-33 or similar imported ones. Trimmer resistors - PV36W or other multi-turn. Capacitors C1 and C12 are size 3216. Relays K1 - K5 G5CLE-14-DC12, they can be replaced with others with 12 V windings, for example automobile ones.

In those shown in Fig. 8 Once the via holes are filled, short pieces of bare wire must be inserted and soldered on both sides. Only after this can you begin soldering the surface mount components, and then the remaining parts, connectors and three jumper wires. For the lithium element G1 on the board, you need to install a holder, which can be found on the motherboard of an old computer, where you can also find a sound emitter (HA1).

Upon completion of installation, the sliders of all trimming resistors are set to the middle position and the program begins to be loaded into the microcontroller. Any in-circuit programmer capable of working with ATmega64 microcontrollers is suitable for this. I would especially like to recommend the one described in the article by S. Sokol “Miniature USB programmer for AVR microcontrollers” (“Radio”, 2012, No. 2, pp. 27-30). The programmer is connected to connector X10. The microcontroller configuration is set in accordance with Fig. 9 in the program window that supports the programmer.

By applying a voltage of +12 V to pin 2 of connector X1 of the BC, perform the programming procedure. If it was successful, you can connect the HG1 LCD to the X3 connector, and the SB2-SB5 buttons to the X5 connector and begin setting up the BC. Now, immediately after power is applied, an image similar to that shown in Fig. should appear on the LCD screen. 10.

By connecting a constant voltage voltmeter between pins 2 (+) and 1 (-) of connector X1, using trimming resistor R7 we achieve equality in the readings of this voltmeter and those displayed on the LCD of the BC. Then we set the trimming resistor R20 to the desired brightness of the LCD screen backlight. If you plan to use a dial speedometer, you need to activate it in the "Other" menu, and then go to the speedometer calibration menu.

Immediately after turning on the bookmaker goes into working mode. If you now press the SB3 “Select” button, the place of the inscription “STOP”, which means that the engine is not running, will be taken by the clock readings. Repeated pressing of the same button will display the daily odometer readings on the LCD, then the permanent (non-resettable) odometer and again the tachometer (“STOP” when the engine is stopped).

Pressing the SB2 “Menu” button will display the main menu of the BC on the LCD (Fig. 11). Pressing it again will move the cursor (highlighting text by inversion) one position down, and upon reaching the end of the menu - to its beginning. Having highlighted the desired item, press the SB3 “Select” button. When the “Exit” item is highlighted, pressing this button returns the BC to the main operating mode.

Let's look at the “SETUP” menu items in order:
"Mode". At this point, you can select one of the four available modes for displaying information on the LCD provided in the microcontroller program. To proceed to its selection, highlight this item and press the SB2 button again. The image will change to that shown in Fig. 12.

The inscription “ok” is displayed next to the current mode; to select another mode, highlight the desired line and press the SB3 button. “Ok” will move to the selected item. To return to the main menu, highlight the “Exit” line and press the SB3 button or, regardless of the cursor position, press the SB4 button.

“Mode 1” corresponds to the image in Fig. 10. When selecting “Mode 2”, the location of the speedometer and tachometer readings will be swapped with a corresponding change in the size of the numbers, and the icons will be moved to another location on the screen (Fig. 13).

This mode is convenient for cars that do not have a tachometer on the instrument panel. In “Mode 3” (Fig. 14), there are no speedometer and tachometer readings on the LCD. Instead, the results of the odometer operation are displayed: daily (resettable), and below it - constant (non-resettable). The SB3 button has no effect in this mode. This mode is suitable for those who are satisfied with the operation of the factory speedometer and tachometer installed in the car. “Mode 4” has not yet been implemented. When you select it, a message about this will be displayed and “Mode 1” will be set.

On-board computer circuit shown in Fig. 2. Its basis is the ATmega64-16AUR (DD1) microcontroller, operating at a clock frequency of 16 MHz, set by the ZQ1 quartz resonator. A programmer is connected to connector X10 for programming the microcontroller already installed on the BC board.

Through the three-pin connector X1, the on-board computer is powered from the vehicle’s on-board network, to the body of which pin 1 of the connector is connected. Pin 2 is connected directly to the positive terminal of the battery. Pin 3 is supplied with +12 V after the ignition switch. It is indicated on the diagram U ACC and should only appear when the ignition key is turned to the appropriate position.

From pin 2 of connector X1 The on-board network voltage is supplied to the integrated stabilizer LM317S (DA1), resistors R1 and R2 are selected so as to obtain 5 V at the output of the stabilizer to power all components of the on-board computer, except for the LCD HG1. The 3V voltage for the indicator is obtained using an integrated stabilizer 78L03 (DA2).

The voltage U ACC through a limiter made of resistor R10 and zener diode VD2 is supplied to the PD3 input of the microcontroller DD1. If the high logic level created by the limiter at this input is absent for more than a minute, the microcontroller goes into sleep mode with reduced power consumption. The work of the bookmaker (except for timekeeping) is suspended. With the appearance of this level, when the ignition key is turned to the appropriate position, the microcontroller will “wake up” and the BC will work.

Voltage U ACC is also used to power the path sensor connected to connector X4. Any one generating from 600 to 27,000 pulses per kilometer is suitable. During the odometer and speedometer calibration process, this number will be taken into account automatically. You can use the factory-installed sensor in the vehicle's gearbox. The common (negative) wire of connector X4 is connected to pin 1, the wire on which pulses are formed during movement, the number of which is proportional to the distance traveled, to pin 2, and the positive power supply wire of the sensor is connected to pin 3.

If the car is equipped with ABS, you can use the sensor included in this system. Its output is connected to pin 2 of the X4 connector with a shielded wire (braided to pin 1 of the connector). Unfortunately, in practice, the operation of the on-board computer circuit with such a sensor has not been tested, although according to calculations everything should function correctly.

Finally, you can apply a homemade path sensor, for example, consisting of four to eight permanent magnets mounted in a circle on one of the axle shafts of the car, and a Hall sensor that reacts to their alternate approach when the axle shaft rotates.
Regardless of the type of sensor, its pulses are sent to an amplifier assembled on a VT5 transistor, and the amplified ones are sent to the PD0 input of the DD1 microcontroller.

"Odometer". Its calibration is very similar to the speedometer calibration. Having reset the odometer readings by pressing the SB1 button, you need to drive along a straight route of known length, for example, measured using a satellite navigator. Then, by selecting the “Odometer” item in the “Calibration” menu, we get an image on the LCD similar to that shown in Fig. 19. Here 6980 m is the route length measured by BC, 326 is the calibration number, which should be in the range 5-9999. Knowing the exact length of the route, we create a proportion similar to that used when calibrating the speedometer, taking into account that increasing the calibration number in this case reduces the BC odometer readings, and vice versa. Having solved the proportion, we find the new value of the calibration number and enter it using the points “+10”, “-10”, “+1”, “-1”. We save the calibration result into the BC memory using the “Save” item.

“Dat. Sveta". To properly adjust the light sensors, you should wait until the evening, so that it is such that you already need to turn on the side lights, but it is too early to turn on the headlights. When selecting “Date. light” the image on the LCD will take the form shown in Fig. 20.
The line “Ex. light YES” means that control of lighting devices based on signals from the light sensor will begin to operate immediately after turning on the ignition. When you set the word “NO” in this line, such control is normally turned off, but it can be turned on and off by pressing the SB4 “Light” button or controlled by the lighting using factory switches.

Parameters “d1” and “d2” are the current levels of sensor signals (photodiodes VD22 and VD23). Please note that the indicator displays hexadecimal values ​​of these parameters, as well as the thresholds for turning on the side lights and headlights. To set thresholds, press the SB2 button to go to the “On” line. size" and then "On. headlights" and use the SB3 button to set the required values. Typically, the threshold for turning on the headlights is set 3-7 units less than the threshold for turning on the side lights.

Two sensors illumination levels are used to reduce the likelihood of false alarms. The lights will turn on only when the signal levels of both sensors are below the threshold. If it is necessary, according to traffic regulations, to turn on the headlights or daytime running lights when moving, regardless of the ambient light, this is done using the “Turning on additional headlights” function discussed below. In this case, the thresholds for turning on headlights and side lights based on signals from light sensors must be set deliberately high, for example, 35 units.

“Dat. rain." The LCD image corresponding to this item is shown in Fig. 21. Please note that here too all numbers are hexadecimal. The top line allows you to turn the rain sensor on and off. The second and third lines display the photodiode signal levels measured with the emitting diodes turned off and on. The fourth line displays the difference between the off and on levels for the first (VD8, VD10) and second (VD9, VD11) pairs of diodes. The next line sets the threshold difference value (in this case 19), above which the windshield wiper will be turned on.

Sensor adjustment must be done directly on the car. It is recommended to do this in the evening or in cloudy weather to minimize the influence of sunlight. First of all, using trimming resistors R46 and R47, set the “off” values ​​in the range of 1-4 and equal for both pairs. Then, trimming resistors R28 and R29 are set to equal “on” values. If the “on” value does not change when the position of the variable resistor slider changes, you need to slightly, literally by fractions of a degree, change the angle of mutual inclination of the diodes of the corresponding pair. The difference between the “off” and “on” values ​​must be at least 15 units.
Having achieved this, we apply a drop of water to the outer surface of the windshield using a syringe in sensitive areas. The difference values ​​should decrease by 5-7 units, but after wiping the glass they should return to the original values. It is recommended to set the response threshold equal to or slightly less than the arithmetic mean value of the difference obtained for two pairs in the presence of water drops on the glass.
If during the daytime the “off” values ​​reach FF and they cannot be reduced with trimming resistors R46 and R47, a light-absorbing film is placed between the windshield and the sensor, for example, used for tinting car windows. The sensor adjustment is repeated again.
Over several months of operation, not a single false alarm of the rain sensor has been observed; the program monitors and corrects its operation, if possible, and if not, the sensor is turned off for a while.

“Const. ode." This item refers to a permanent (non-resettable) odometer that calculates the total mileage of the vehicle. It is available only during the first twenty starts of the bookmaker. Here you can set the initial value of the odometer reading so that it continues calculating the mileage started by the previously installed device on the car. The LCD screen takes the form shown in Fig. 22. Pressing the SB2 button moves the selection from digit to digit, and using the SB3 button changes the highlighted digit in the range 0-9. This makes it possible to set any initial value, up to 999999 km. When the mileage has been entered, go to the “Save” item, press the SB3 (Select) button, and if everything is entered correctly, the message “Value saved” will appear on the screen. The item remains available for changes until the bookmaker counts 20 inclusions.
« Rest«. This is the last item in the main menu. When you select it, the submenu shown in Fig. 1 is displayed on the LCD. 23.

In line « Art. AIDS« The dial speedometer may be turned on or off. To use such a speedometer, you must first calibrate it by selecting the “Speedometer” item in the “Calibration” menu when the dial speedometer is activated. In this case, in the image on the LCD, in contrast to the previously discussed one (see Fig. 18), a new line “Arrow=80” will appear (Fig. 24), and the speedometer needle will smoothly deflect to a position corresponding to a speed of 80 km/h.
Using the adjusted resistor R21, it must be set exactly to the corresponding scale division. Next, highlight the line “Arrow=80” and press the SB3 button. The speed value will begin to gradually increase to 120 km/h and gradually decrease to zero. The speedometer needle will follow it. Then the cycle will repeat. This will allow you to check the correctness and accuracy of the speedometer dial.

In line " Dat. rain » turn on and off the windshield wiper control from the rain sensor, and in the line “Control. dvorn." - control of the windshield wiper using the SB5 button. You can choose the first or second control method, or even prohibit the BC from controlling the wiper.
When you select the “Statistics” line, the LCD displays information about the engine operating time and travel time in hours and minutes (Fig. 25). You can reset it in two ways: by selecting the appropriate menu item or by long (more than 3 s) pressing the SB1 button. In the latter case, both statistics and odometer will be reset.

Line " Add. light« allows you to turn the daytime running lights control on or off. If it says “ok”, this function is active. The lights will turn on immediately after you start driving, regardless of weather conditions and time of day, and turn off when the engine is stopped.
All set parameters, odometer results and statistics are stored in the non-volatile memory of the microcontroller and are saved when the power is turned off.
According to the algorithm embedded in the microcontroller program, immediately after turning the ignition key, the BC begins to work, displaying information on the LCD according to the selected mode. If the warning function about the need to change the oil is turned on and less than 2000 km are left to travel, a corresponding message will be displayed, and after 2 s the BC will return to operating mode. After starting the engine, the tachometer will display the crankshaft speed, and as soon as the car starts moving, the speedometer will show its current speed.
When dusk comes and BC The side lights will automatically turn on and their icon will appear on the LCD. When it becomes completely dark and the low beam of the headlights turns on, the pictogram will take the form of a headlight on.

If the ignition is turned on in the dark, the side lights will turn on immediately, and the low beam will turn on when the car starts moving. At dawn, the headlights will be turned off first, followed by the side lights. These lights, and, if necessary, the headlights, will also turn on when entering a dark tunnel. If the car remains stationary for more than 5 minutes at night, the headlights will be turned off and the side lights will remain on. The headlights will turn on as soon as the car starts moving. You can forcefully turn off the side lights and headlights by pressing the SB4 button. Pressing it again will return lighting control to the BC. Since the factory-installed light switch remains in place, you can use it.

Where the traffic rules are require you to turn on the lighting while driving, regardless of the time of day, you can use the corresponding function. When it is active, moving the car away with the engine running will turn on the daytime running lights. They will turn off as soon as the engine is turned off.
If the windshield wiper is controlled by a rain sensor, it will work as soon as raindrops appear on the windshield within the sensor's coverage area. The windshield wiper speed is selected automatically depending on the intensity of the rain and the speed of the vehicle. You can forcefully turn off the windshield wiper by pressing the SB5 button, and pressing it again will re-enable control based on sensor signals. You can turn on the windshield wiper and washer manually using the standard switch.

If in the SETUP menu If the windshield wiper control is set with the SB5 button, then the first press on it will turn on the windshield wiper with pauses, the duration of which depends on the speed of the vehicle. Pressing it again will turn the wiper on continuously at low speed, a third time will turn it on at high speed, and a fourth time will turn it off. You can stop the wiper operation, regardless of the selected mode, by long (more than 5 s) pressing the SB5 button. All operating modes of the windshield wiper are displayed by pictograms on the LCD.

If the on-board voltage vehicle has exceeded the permissible limits, a battery icon and a description of the problem will appear on the LCD, a beep will sound three times and the LCD backlight will flash the same number of times. Then the bookmaker will return to normal operation. When the temperature outside the car is close to zero, the “Slippery road” icon and the inscription “Attention! There may be icy conditions." These warnings cannot be blocked.

The BC constantly monitors the condition of the doors, hood and trunk. As soon as at least one door, hood or trunk is open, a picture will appear on the LCD indicating their status (Fig. 26). Return to operating mode will occur when everything is closed, or after pressing the SB3 button.
After turning the ignition key in the “OFF” position, the headlights and the windshield wiper (if they were turned on) will turn off instantly, and the BC itself will turn off in about a minute. If, after turning the key, a door, hood or trunk remains open, the CU will not turn off, displaying their status until everything is closed.

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I. MAZURENKO, Odessa, Ukraine
"Radio" No. 1 2013

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