Answers for F.A.Q. about the microprocessor ignition system SECU-3.
Usually, it takes 3-5 working days to prepare your order for shipment (excluding days off and holidays).
You can view status of your order in the Personal area.
Without going into details, the installation of the microprocessor ignition system will provide the injector advantages to your carburetor. Including:
- better acceleration and dynamics in all operating modes of engine
- engine operation stability (independence of mechanical “whims” of distributor)
- automatic support of idle running by means of ignition advance angle (idle running rotations don’t change when headlights, heater and other powerful consumers are switched on)
- easier startup in winter time
- separate and independent setting of gas. Car drives using gas or benzene equally.
- during acceleration the detonation is absent (“pin knocking”), which destroys piston
- it is possible to control the rotation speed of cooling fan (lower noise, more stable engine temperature)
- starter is shutting down automatically when engine is already running
- it is possible to control the electrical fuel pump (pumps fuel only when it’s necessary)
- it’s possible to install individual coils on each cylinder
- it’s possible to control the choke by means of stepper motor (choke position is set automatically depending upon the engine temperature)
And also: outlet for tachometer, built-in stroboscope for ignition adjustment, control of idle cut off valve, power valve control, switching of performance on the run using button (switching between 4 settings), reassignable inputs-outputs, lambda probe connection for engine operation analyses and etc.
All main parameters of microprocessor ignition system SECU-3 could be adjusted on the run using laptop.
Microprocessor ignition system SECU-3 could be installed on cars with carburetor.
Most often microprocessor ignition system is installed in classic cars; it is easy enough to install microprocessor ignition system in Tavria. The author of the SECU-3 project installed microprocessor ignition system firstly in Moskvich 2141. But this is far from being a full list. There are users, who installed our microprocessor ignition system in AUDI, OPEL, VW and other cars. They install microprocessor ignition system in foreign brand cars either because of high price of distributor or when standard ignition system fails, which is difficult to find or its value exceeds the value of SECU-3 in many times.
It’s also possible to install microprocessor ignition system on monoinjector to control the ignition.
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We answer all the questions, even foolish ones)))
The warranty for production lasts till 6 months since sale.
The warranty is valid on conditions that there is no intervention into the electrical circuit of unit and that there are no electrical damages.
If you are not satisfied with operation of the microprocessor ignition system you can return it during 2 weeks.
Delivery expenditures and bank fee are not indemnified to customer.
Yes, we do. All units of microprocessor ignition system SECU-3T without exception are tested on test board and programmed with the last firmware release. You receive units, which are completely tested and ready for adjustment for concrete engine.
The units have following modifications:
- With USB interface with or without built-in MAP sensor
- With RS232 interface (COM port) without built-in MAP sensor
The synchronization mode from the distributor Hall sensor is available. Thus it’s possible to install microprocessor ignition system SECU-3T without using a pulley for synchronization. Thereby to install microprocessor ignition system SECU-3 unit you will minimally need only SECU-3 unit with MAP sensor and simple alteration of distributor, where you will simplify it.
To get more exact formation of ignition advance angle it is recommended to use a pulley for synchronization. The system supports pulleys with teeth quantity from 16 to 200. The most widespread pulley is 60-2 (60 teeth and 2 of them are missing). This pulley should be placed on the crankshaft and in front of its teeth the CKP sensor should be fastened. Usually they take the pulley from injector version of this engine or produce it themselves.
Also it’s obligatory to install the MAP sensor if it’s missing in microprocessor ignition system unit, limit switch of carburetor and CTS advisable.
These are minimal configurations for connection of SECU-3T ignition unit.
Other system components could be installed as an option or necessarily.
The delivery is carried out worldwide by means of air mail with track number.
The delivery is carried out in Ukraine by Ukrposhta, Novaposhta or by other private carrier according to arrangement.
Ready-made units are programmed with the latest for sale date release.
You may need to program the unit if you want to use new functions, which have appeared in new release. The programming is carried out by manager. More detailed information is given in answers below or in manager manual
Release – is stable and tested version of program. In our case – of unit firmware and manager program.
Site menu – download section – software releases. Choose the latest by date.
Manager version is not compatible with firmware.
Use manager from the same release as unit firmware!
1. Connect unit to PC and supply power to it, run manager from the same release as firmware.
2. Go to the tab “Firmware data” in manager and push the button “Operations with firmware” there.
3. In menu, which will appear, choose the line “Record FLASH to SECU-3 from file”.
4. The window for choosing file will appear. Choose Hex instead of Bin in falling down list in the line “File type” below.
5. Go to folder containing firmware archive, choose the needed firmware file and press “Open”.
6. Wait till the programming finishes (percentage scale will run at the foot of manager window).
Do not disconnect power supply, do not close manager and do not go to other tabs during programming!
1. Download the latest firmware and manager from the page The last tested firmware and manager
2. Program the unit using old manager with new, downloaded firmware.
3. After the programming finishes use new downloaded manager.
In some cases (update from very old firmware) it is necessary to carry out the procedure of EEPROM reset after programming. Hereby all settings will reset to on default.
You don’t have to reset EEPROM obligatory, if you update from previous release and the necessity to reset EEPROM is not specified obviously.
Read the next answer to get to know how to program.
Yes, it is possible. For this aim you need to open firmware file on the manager tab “Firmware data”. To open firmware file you need to choose menu item “Open firmware from file”. Menu is activated by pushing the button “Actions with firmware”.
After opening of firmware it’s possible to edit all curves included in firmware and, besides, import set of curves from files *.s3f, *.mpz, *.mpx and other firmwares.
*.s3f – is own format of microprocessor ignition system SECU.
This files format contains characteristics set of ignition advance angle and tables of attenuator, CTS, choke opening and accumulation time.
The parameter “Upper pressure” on the tab “Functions” is set to value, which is displayed by device as “Absolute pressure” with throttle fully opened and maximal load, for instance, on 4-th drive and speed 40km/h. The parameter “Lower pressure” is set to value, which is displayed with device as “Absolute pressure” with throttle fully closed and maximal rotations, for example, forced idling. As a rule this means 90kPa and 30kPa.
This is very important question, because in case of incorrect connection the problems with ignition operation may appear because of high noises created by high currents and voltages on igniters outputs and ignition coils. “+” of igniters power supply and of unit should be connected to ignition lock with their own separate wire and ignition coils with their own separate wire. “-” of unit power supply and of each igniter should be connected to the ground also with separate wires. The wires should have the appropriate cross section.
To install this system the idle cut off valve is not obligatory; the system can operate even without it.
The sensors and components list for microprocessor ignition system SECU-3 is available on the page Sensors and components
For wireless connection to microprocessor ignition system SECU-3T unit.
Yes, it will operate, but not simultaneously. If USB cable is connected you should break the wireless connection and vice-versa, if you connect via Bluetooth – disconnect USB cable.
To control the choke you will need microprocessor ignition system SECU-3T unit and also:
– choke control unit (availability and price are on the page Production )
– stepper motor 2170-8127100 (Servomotor of air flow distribution) http://kzta.ru/portfolio-item/motoreduktor-raspredeleniya-vozdushnogo-potoka-2170-8127100/
Manual for servomotor installation on carburetors “Solex” is available here here.
Yes, it is possible. The firmware can be built by means of GCC not only on MS Windows, but also on Linux. To run SECU-3 Manager on Linux use Wine (http://www.winehq.org/). The development of software for Linux, which is analogous to SECU-3 Manager, is carried on simultaneously.
Install Wine in any suitable way for you (for instance, using Ubuntu Software Center, from terminal, from sources and etc.). Then adjust needed COM port. To view the list of available COM ports, type in terminal:
As the devices name in Windows and in Linux is different, it’s needed to create a link for device (e.g. /dev/ttyUSB0) in folder ~/.wine/dosdevices by typing the command
ln -s /dev/ttyUSB0 ~/.wine/dosdevices/com1
Besides you need to point the correct device name and needed number of COM port. That’s all!
Q: What is the difference between boards of revision А (revA) and revision B U4 (revB U4)?
A: Revision B is newer than revision A. Differences of revB U4 in comparison with revA:
- pin configuration is carried out only for USB
- ESD protection of controller ADC intputs was added (pin configuration is separate)
- The pin configuration ability for TPS hardware support was added
- Board contour was changed
Q: Several variants of printed circuit boards for unassisted production are available on site, which one should I choose?
A: Choose the one, which you are able to produce and assemble by yourself. Possibly, alternative printed circuit boards will have lower functionality, but they could be simpler to produce. It’s a good idea to care about case before you start printed circuit board production.
Q: I heard that optical isolation of microcontroller with PC СОМ was weak point in system. What cross coupling should I assemble?
A: Problems occurred in earlier scheme on two optical couplers. In last variant of original scheme was applied optical isolation on three optical couplers, in this case no problems occur. The optical isolation favors better protection of microcontroller and PC input circuits, which is especially important if you connect laptop with power supply from autoinvertor 12->200V. If optical isolation is not actual, it is possible to assemble the scheme based on classical MAX232, on two transistors, or use ready-made bridge USB2COM taken out of Chinese USB data cable. Besides, SECU-3T units with board of rev. 9 and higher have USB support (optionally).
Q: There a slot on scheme marked as ISP Adapter, what is this?
A: This is slot for initial controller programming. That is controller soldered firstly, and then programmed, but not vice-versa. Simple adapter, which is connected to parallel PC port, is used as programmer. The simplest adaptor will consist of five wires, more complex adaptors contain buffer chip. One of adaptor variants is available in this archive . Read more here and here . Besides, there is a lot of ISP programmers, which are connected to PC via USB, e.g. AVR910 USB.
Q: How and by means of what can I program SECU-3 unit primarily after assembly?
A: To program the unit means to record the program into flash memory of microcontroller. This program, being once recorded, can program itself besides its main functions. This function is carried out by so called boot loader, which size is equal to 512 bytes and which is located at the end of flash memory. But to use the boot loader abilities you need once to record it there. That is why:
After device assembly it needs to be configured once and programmed via service slot, which is marked on the scheme as ISP Adapter. It is recommended to carry out both operations by means of AVReAl. Of course, during such operations the needed unit power supply should be from +12V.
Run parameters of avreal.exe are following.
Fuses installation (configuration):
avreal32.exe -as -p1 +atmega16 -o16MHZ -w -fBODLEVEL=ON,BODEN=ON,SUT=01,CKSEL=F,CKOPT=ON,EESAVE=ON, BOOTRST=ON,JTAGEN=OFF,BOOTSZ=2
avreal32.exe -as -p1 +atmega16 -o16MHZ -e -w secu-3_app.a90
p.s. examples are given for ATMega16, LPT1 port is used.
Archive with bat-files for check sum patching, fuses installation and programming here
Pay special attention that in service mode firmware file means file in hexadecimal (hex) format with extension *.a90 or *.hex, with size > 30kb, and containing symbols of hexadecimal system only 0-9ABCDEF. If everything is done correctly, during next reboot the unit will “blink” once with LED, which is connected via the resistor between CE output and ground (SECU-3) or +12V (SECU-3T). At this moment the service mode can be considered as finished and all following program changes could be done in user mode.
User mode: For user mode you will need manager (control program for PC) and operational COM port, connected to SECU-3 with usual COM port extender.
If your unit is equipped with USB interface, you will need USB-cable (like for printer). If manager reports during the start about the impossibility of COM port opening, then you need to adjust the correct port number in manager or look for troubles in operating system.
Pay special attention that in user mode the firmware file means file in *.bin format containing any symbols, but size of this file can be only: 16384 bytes for ATMega16 or 32768 bytes for ATMega32. To convert firmware from hexadecimal format to binary, you need to use utility hex2bin.exe. The reverse converse will be not needed. SECU-3 recognizes files both in hexadecimal and binary formats. User mode could be divided into boot loader mode and operating mode: Boot loader mode: Entry to this mode happens when power is supplied and jumper “boot loader” is installed. At this moment the main part of program doesn’t operate, only boot loader is operating, which is able to read or record the main program into microcontroller flash memory by commands from manager. For this aim you need to set check box “Boot loader is running in emergence” on the tab “Firmware data” in manager and choose the needed operation by pushing RMB. This mode should be used only in case if the main program is corrupted, if it still operates, all these operations could be done in usual mode, of course, only when engine is not operating. Operating mode: jumper “boot loader” is removed, status is “connected”, tab “Parameters and monitor” is active. Operations by pushing RMB are available on tab “Firmware data”.
Q: Where can I find the last versions of firmware and manager?
A: Firmware in hexadecimal format here , to convert it to binary format use utility hextobin.exe. Several different firmware files are available in repository (for SECU-3 and different versions of SECU-3T ). Manager is available here.
Q: Where can I find tested versions of firmware and manager?
A: On the main page of site, section “Downloads”.
Q: What speed of СОМ port should be chosen in manager settings?
A: Both speed values could be set less or equal to 57600 bauds.
Q: How to carry out the ADC calibration correctly?
А:Measuring with digital voltmeter the voltage, which comes to analogue unit outputs, try to obtain the same values in manager with option set “Show raw values of sensors”. For this aim you need to choose parameters on tab “ADC error compensation”. As a rule, you need to change only factor, unlikely you will need the compensation. Probably, all three factors will be the same.
Q: How to carry out the MAP sensor calibration correctly?
А: You need to choose the value of parameters “Offset” and “Slope” on tab “Functions” so that with engine not operating the device “Absolute pressure” would show current atmospheric pressure. As a rule, this value averages 99-10kPa. Table of pressure conversion to different units. Sense of parameter “Offset” is described on picture. Parameter “Slope” defines by how many kilo-Pascals should the pressure change so that the voltage at sensor output would change by 1 volt.
Settings for MAP sensor МРХ4100: Curve slope – 18.51 kPa/V, curve offset – 0.78V.
1. Slope is specified in technical specification – 54mV/kPa. We need units kPa/V. Correspondingly, curve slope measured in our units will be equal to 1 kPa/ 0.054 volt= 18.51 (kPa/V). This is the curve slope, which we will set in program manager.
2. It is necessary to find pressure and corresponding voltage in technical documentation for sensor. It is pointed in technical specification that by pressure 20kPa sensor gives approximately 0.3V. These values are usually available in documentation for sensor or on diagram or in table.
Then, according to formula, we find “Curve offset”.
Curve offset = (pressure from documentation/curve slope) – voltage from documentation.
Curve offset = 20/18,51-0,3V = 0,78 V
Well, we calculated “Curve slope” = 18,51 kPa/V, and “Curve offset” = 0,78 V.
Now we need to set obtained values in program manager.
Sometimes you can find MAP sensors with reverse characteristic (shown on picture).
The offset for such sensors is calculated with the same formula:
Curve offset = (pressure from documentation/curve slope) – voltage from documentation.
Example: Sensor gives 4.5V with pressure 20kPa and has curve slope equal to -25.7 kPa, then:
Curve offset = (20/25,7) – 4,5 = -3,72V
To point that we use the sensor with reverse characteristic it necessary to point the curve slope with “-” sign. E.g. as shown below:
Q: On mpsz.ru they use such terms as “Starting pressure” and “MAP sensor slope”, how to do, like they have it?
A:“Starting pressure” = “Atmospheric pressure” – “Upper pressure”
“MAP sensor slope” = (“Upper pressure” – “Lower pressure”)/16/”Curve slope”/0,02-3.
“Upper pressure” = 94kPa, “Lower pressure” = 30kPa, then “Pressure range” = 94 – 30 = 64kPa
One consumption contains 64/16 = 4kPa, or one consumption contains 4/20 = 0,2 V.
In “micro chip” discretes of ADC this will make 0,2/0,02 = 10 discretes;
Altogether MAP sensor slope: 10 – 3 = 7 “parrots” (dimensionless units).
Q: Will the system operate if I don’t install HIP9011? I’m in difficulty to buy it.
A: Yes, it will operate. Installation of HIP9011 is not obligatory (optional).
Q: How to make manager operate on WIN98SE?
A: Try to copy these libraries to C:\Windows\System, or put them near the manager.
Q: I have troubles while reading FLASH from SECU-3 or during other operations, connection with unit breaks…
A: Try to set hardware control of flow in settings of COM-port.
Q: How to choose the frequency of band-pass filter HIP9011 correctly?
A: The frequency of band-pass filter should be equal (approximately) to detonation frequency. Detonation has different frequency in different engine types. To calculate the theoretical detonation frequency of your engine, use simple formula: 900/(Pi * radius). Thus, if you use cylinder with diameter 81mm, you can calculate following detonation frequency: 900/(3.141 * 40.5) = 900/127.2105 = 7.074 kHz. Also you can use online calculator.
Set the band-pass filter to frequency, which is the closest (kHz) to calculated detonation frequency.
Reliable method to find out the exactly detonation frequency is to record the sound of your engine operating with detonation. Then carry out spectral analysis. The spectral analysis could be carried out, for instance, by means of sound editor Cool Edit Pro.
Q: Is it bad, if schematic circuit drawing, printed circuit board drawing and electronic components specification have different revisions?
A: While editing of each document, the number of revision increases by 1. These are different documents, and if one of them is edited, other ones could remain unchanged; correspondingly, the revision numbers will be different.
Q: What is needed for this ignition system to operate with six-cylinder engine?
A: The same as for another number cylinder engine – CKP sensor, MAP sensor and etc. The system supports 1, 2, 3, 4, 5, 6- and 8- cylinder engines. System SECU-3T can operate in 6-ignition channel mode (separate coil for each cylinder). If desired, number of ignition channels can be increased up to 8.
Q:What MAP-sensors could be used besides 45.3829?
A: Any else with similar characteristic. For example: 14.3814 (analog 12.569.240), MPX4250, MPX4100A and so on.
Following will be suitable:
ALFA ROMEO 60811534, CITROEN/PEUGEOT 1920 4S, CITROEN/PEUGEOT 1920 FC, CITROEN/PEUGEOT 5946 07, CITROEN/PEUGEOT 5946 09, DAEWOO 16137039, FIAT 7696064, FORD 1144809, FORD 1C1Y 9F479 AA, GENERAL MOTORS 12 569 240, GENERAL MOTORS 16 137 039, GENERAL MOTORS 9 389 131, HOLDEN 16017460, HOLDEN 16137039, HOLDEN 8161370390, HYUNDAI 39330-24750, KIA 0K950 18 211, OPEL 12 38 788, OPEL 62 38 927, OPEL 8 15 701, RENAULT 77 00 706 876, RENAULT 89 33 000 153, VOLVO 1378162, VOLVO 3411400, DELPHI PS10075, DELPHI PS10075-11B1, FACET 10.3001, HELLA 6PP 009 400-071, INTERMOTOR 16800, MEAT & DORIA 82052, PIERBURG 7.18222.01.0
Q: What is the meaning of parameters “fact.” and “corr.” on parameters’ tab of SECU-3 “7:ADC errors corr.” in manager?A: These parameters are needed for ADC calibration and input voltage dividers at ADC input. Meaning of these parameters can be described with a simple formula: Uadjusted = (Uincoming * factor) + correction
factor – scales the function;
correction – offsets the function.
Q: Manager hangs and in couple of minutes Windows 7 crashes into blue screen. SECU-3 is connected to laptop via USB–>COM adapter. What can be the reason?
A: The trouble of blue screen on Windows 7 (and not only) is caused by low quality of drivers for Chinese USB–>COM adapters. Trouble occurs when big data flow comes to receiver input. To solve the problem you can try to increase the period of SECU-3 data sending (see SECU-3 parameters’ tab “Misc” in manager).
Q: Do I need to compile the firmware?
A: The part of firmware functionality is determined during compilation time. You need to recompile the firmware only if options, with which it was compiled on default, seem to be not suitable for you. The binary file of latest firmware version is available in repository together with source code.
Q: Why do I need the dwell time and how do I calculate it correctly for my coil?
A: SECU-3 can control dwell time of ignition coils. This gives an opportunity to refuse to use igniters and to apply the ignition modules or simple schemes on IGBT. The control task is to pass the current through the coil when current’s increasing brings to magnetic field amplification in coil. If we “undercharge” the coil we’ll have poor spark, if we’ll try to “overcharge”, the current will be limited by active resistance of coil and excess energy will turn into the heat. Dwell time is easy to define by two methods.
First method. To measure practically by means of square-ware generator, laboratory power supply and oscilloscope (to measure the current in coil, voltage at shunt is measured). For set voltage you should choose pulse frequency and observe changes of the current on oscilloscope screen. Fill the table with obtained values for each voltage value.
Second way. Calculate according to formula (You need to know L and R).
T = (-L / R) * ln( 1 – (R * I / V)),
T – dwell time (in seconds), L – coil inductance (Henry), R – coil resistance (Ohm), I – current (A), V – voltage (Volts),
ln – natural logarithm (is available in any calculator).
Q:What is the difference between SECU-3T and SECU-3 units?
A: SECU-3T is further development of SECU-3 unit. Many small suggestions of users are taken into account and some functions are added in it. For instance, support of the USB interface appeared in the SECU-3T (by user desire it can be assembled either with USB or RS-232 interface with optical isolation). SECU-3T has several additional inputs and outputs. Both units have the same firmware (compatibility on the level of program’s source code).
Q: Manager doesn’t see the unit after firmware update.
A: New firmwares can storage data in EEPROM in format, which is not compatible with old firmwares, in this case you need to run the unit after programming with jumper set “Default EEPROM”. The jumper should be removed after first run and connection with manager. It should be mentioned, if you reprogram the unit for the same firmware version, which was before, it is not obligatory to set the jumper “Default EEPROM” by first run of unit.
Q: Here can be your question!