The GenBoard v3 ECU is an open source, Do-It-Yourself, programmable controller that can be used for multiple applications. The primary and most popular use of the GenBoard is for Electronic Fuel Injection on internal combustion engines. The goal of this manual is to explain what is involved in using the GenBoard for use in an EFI system and to lead you through the construction, installation, programming, and tuning of this application.
The Versatile Engine Management Systems (VEMS) website is run by volunteers and is a vehicle for the research, design, and implementation of open source engine solutions that target performance, reliability, low cost, and versatility. It is also a vehicle of self-learning and fun.
Do-It-Yourself engine management became very popular around 2000 to 2001 with entry-level systems supporting batch injection only. VEMS took it to another level with the added functionality of sequential injection, direct ignition control, wideband oxygen monitoring, detonation detection, exhaust gas temperature monitoring, and the ability to expand.
While there is a large network of resources and people for helping you with the GenBoard use, you are ultimately responsible for any errors, problems, and subsequent damage that may occur to any engine running on GenBoard. You must read and understand this manual before starting your GenBoard project so that you may understand what is involved and successfully complete your GenBoard installation.
GenBoard v3 ECU Target Features
Support for most common trigger arrangements.
1-8 cylinder full sequential injection with coil on plug/coil near plug, wasted spark, or 1-2 distributors. Or, 10-16 cylinder semi-sequential with wasted-spark/ 1-2 distributors.
Wide open throttle closed loop Lambda control (WOT closed loop) - lambda (AFR) mapable through entire loadsite-range (pressure, RPM)
Self learning VE table
2 channel acoustic knock sensing. Ignition can be configured to be adjusted automatically within a range from configured reference table
Integrated fully mappable, digitally controlled BoostController
2 channel exhaust gas temperature (EGT)
Advanced idle control using bipolar stepper or (ON/OFF or PWM) solenoid and ignition advance for fine adjustments. Together with precise all-loadsites WBO2 this results in awesome idle quality if tuned properly
GenBoard v3 is the most advanced opensource engine management system ever designed. (open source means you can join the team, learn from it, add features). The firmware that was originally written for GenBoard/VerTwo (and running in daily drives since 2003 February) was extended so it supports the new design. V3 went through integration testing in February and March 2004, running real engines using ignition, injection, wide band oxygen sensor, stepper idle air control, LCD display, and table-tests. Everything works exactly as expected. Subsystems and most firmware code were tested earlier in the design phase.
GenBoard ECM and firmware features a very precise and very fast internal digital WBO2 controller that can be used for EGO correction in the full operating range, as well as wide open throttle (WOT). This feature is not available in any other opensource or reasonably priced ECM. The lambda (AFR) is fully mappable like the other tables (8x8 or 16x8); in practice, tuning to lambda-target is much easier, more precise and faster than raw VE that is required for simpler ECMs (95% on the market, and 100% below 1500 Euro). With the help of lambda-target the VE can be auto-learned. Fully mappable boost controller and individual-cylinder acoustic knock-detection (not available in any other opensource or reasonably priced ECM) are also nice features. Firmware support for some optional parts are still under development and testing, eg. the logging runtime data (without notebook or PDA, eg. in a racecar) into large capacity MMC disks for later analysis.
Assembled v3 Unit
GenBoard v3.x Resources and Specifications
8 high current and high voltage ignition drivers that can directly drive coils (max 16 cylinders with wasted spark). These can also drive other devices (with max 8A/380V load with the standard hardware)
8 high current injection drivers supporting peak-hold injectors or other devices (with max 14A/60V load with the standard hardware)
2 high current miscellaneous outputs. These drivers, as well as the 8 injector drivers can be configured as high current (14 .. 15 A) drivers for special outputs (idle pulsewidth-modulated (PWM) or ON/OFF solenoid, nitrous oxide injector, variable intake actuator, etc...)
1 Idle stepper driver. Can be used as four individual 1A push-pull drivers
4 350mA protected open collector drivers with pullup
1 350mA protected open collector driver for fuel pump relay
1 350mA protected open collector driver for small idle solenoids
2 350mA protected open collector drivers driving LED's. Available for other applications if connected on board.
2 RS232 ports
1 1-wire communications port (replaces one RS232) for very convenient anti-theft (see Button Immobilizer) support
1 onboard LCD support
1 Onboard PS/2 keyboard support
Feature connector for CAN bus and MMC (multimedia card) add-on boards
Fast serial boot loader for firmware updates
2 variable reluctance/Hall sensor inputs
2 knock sensor inputs with advanced DSP based signal conditioning
Onboard manifold absolute pressure sensor (MAP) with high precision processing. 2048 signal levels is noticably better (smoother idling, more precise tuning) than the 256 levels often used: especially on turbo engines.
Coolant temperature sensor (CLT)
Intake Air Temperature sensor (IAT)
Throttle position sensor (TPS)
2 misc inputs for resistive sensors, like exhaust back pressure and fuel pressure
2 LSU4 wideband oxygen controllers providing fast and precise digital control
2 K-Type exhaust gas temperature (EGT) sensor amplifiers
Several internal sensor inputs for custom applications
Enclusure and connectors:
Automotive grade AMP Econoseal III connectors
Extruded Alubos aluminum enclosure with CNC machined endplates
Versions : v3.0, v3.1, v3.2, v3.x
v3.0 was the initial release designed 2003 August .. 2004 February
v3.1 minor cosmetic PCB modifications for a bigger series planned 2003.04.13 after the success of v3.0
change main regulator to more available MC33269DT-5 and split supplies (add several other regulators), higher assembly level, bottom side automated as well
PWMing (low-Z support) automated with 4xMC33151D FETdrivers on all boards (so WebShop PWM-ing kit means no added items when ordered together with v3.2)
pads for 2 extra-FETs (DPAK on v3.2)
note that 8 IGBT + 10 FETs are still TO220, they were NOT assembled in the automated process (as it is only feasible to do for SMD components): nothing changes in this respect.
v3.x: general name, can be v3.0, v3.1, v3.2 ...