Chapter 3. The Hardware

Table of Contents

Basic Hardware Functions
ECU Connectors
The Econoseal Connectors
RS-232 Serial Connector
Keyboard Connection
LCD Connection
Standard Wiring Diagrams
Standard Sensor Inputs
Throttle Position Sensor
Intake Air Temperature Sensor
Coolant Temperature Sensor
Manifold Air Pressure Sensor
Wideband O2 Sensor
Exhaust Gas Temperature
Triggers
Knock
Fuel & Exhaust Pressure Sensors
Standard Outputs/Drivers
Injectors
Coils/Misc Drivers
Fuel Pump Relay
Idle Air Actuator
Idle Air Motor
Interfacing the Genboard

This chapter has been designed to help you, the user, to assemble, customize, and install the remainder of Genboard V.3 ECU. We intend to accomplish some teaching of the following items in this chapter:

We want to make this as painless as possible. The following sections will hopefully give you a basic idea of what goes on in the circuitry, a glance of Genboard potential, and a follow-up of some straightforward standard automotive wiring. Finally, we will discuss different ways to interface with your Genboard V.3 ECU. More advanced topics will be covered in the appendix and will be noted as such.

Basic Hardware Functions

The features described in Chapter 1 touched on this section. However, here the discussion will help to relate those basic features into what they can be used for generally, and then some more advanced uses will be touched upon.

The 8 ignition drivers are composed of a logic level IGBT that supports continuous 14-amps. Ignition coils, DI or DIS, are generally connected with their positive terminal to 12 volts and the negative terminal is connected to the Genboard. These drivers take the negative terminal and connect it to ground when the gate input is triggered.

The 8 injection drivers support peak-hold injectors. Each injector’s positive terminal is connected to a fused common 12-volt supply while the ground is run back to the board. These injection drivers connect the injector’s ground to an actual ground when the gate input is triggered in a pulse width modulated (PWM) format. Each injector uses a15A, 9.5nC, Rds = 0.055, logic level, insulated FET and we have incorporated flyback protection into the driver circuit itself.

There are 2 High current outputs used for miscellaneous functions. These drivers are built the same as the injector drivers and can be configured as high current (14 to 15 A) drivers for special outputs. Examples of these include:

  • Boost control with vacuum or electronic actuator

  • Nitrous control

  • Water injection

  • Alcohol injection

  • Variable intake actuator

  • Relay/Solenoid for whatever you need

Stepper driver circuit goes here just like above...

Open collector driver circuit goes here just like above …

Pulse width modulated inputs for triggers here just like above …

Analog to digital inputs for sensors here just like above …

Flyback circuits are used to protect the switching equipment (the injector driver FETs) from extremely high voltages that could occur when the inductive load is switched off. While the load is switched off, voltage builds up and must be dissipated somehow so that we don’t burn up the FETs. Some FETs can handle some abuse in this manner, but still, their ability to deal with the high voltage is not sufficient, so we use a high voltage switching flyback to take care of it. Compared to a Zener diode setup, the switching flyback allows quicker switching (for quicker closing of injectors), longer life, less heat buildup, and returns the voltage to the injector common (12-volt VBATT) instead of to a ground connection, as is used in other systems.

Anything else?