EZ-B v3 Info

The discontinued EZ-B v3 was sold between 2011 and 2013. This section provides technical support for existing EZ-B v3 users.

We will start by explaining how add-ons work with the EZ-B Robot Controller Board, and how they are connected. Throughout the documentation and DIY Projects, there are mentions of ports: ADC and Digital.

Here is a tutorial that demonstrates how to connect to the discontinued EZ-B v3 while it is still supported in EZ-Builder.

EZ-B v3 Dimensions

This dimension template will come in handy if you are mounting the EZ-B to a surface within your robot. Or, perhaps you need to verify if there is enough room in your robot for the EZ-B.

EZ-B v3 CAD Design

Our valued member Bborastero has created this Community Thread with a 3D Sketchup Design file of the EZ-B.


The EZ-B has 20 Digital Ports and 8 Analog Ports. The Digital Ports are labelled D0 through D19. The ADC Analog Ports are labelled A0 through A7

Each port has 3 pins, which are Gnd, +5 and Signal. The Gnd and +5 are for powering the device connected to the port. The Signal pin is connected to the EZ-B Microchip for reading or writing data from Digital or ADC. The Gnd and +5 pins are not connected to the Microchip, they are used only for powering the peripheral connected to the EZ-B.

For example, a servo has a 3 wire plug that connects to one of the EZ-B Digital Ports. The wires of a servo connector are Gnd, +5 and Signal. The Gnd and +5 power the motor and circuit within the servo. The Signal wire carries the information to tell the servo what position to move.

Working with digital means True (On) or False (Off). True means +5 voltage, and False means GND. There are 20 digital ports on the EZ-B (D0 to D19)

Output is writing to a port: When a port has its digital value set to True, then a +5 voltage will be outputted on that port. If the port has its digital value set to False, then the port will be GND.

Input, is reading from a port: You can read the value of a specific port. This is how you can check for voltage, On or Off. Any voltage above GND will be returned True, a short to GND will be returned as False.

Example peripherals for digital are Triggers, Switches, Servos and Buttons.

Means Analog Digital Converter, and is read only (input only). This method reads voltages into the EZ-B Robot Controller. There are 8 analog input port on the EZ-B (A0 to A7).

Reading Relative Voltage: The returned value will be between 0 and 255 that represents the input voltage on the specified port. The value will be relative to the input voltage that will between 0 and 5 volts. Example: Value 0 = 0 Volts, Value 127 = 2.5 Volts, Value 255 = 5 Volts.

Reading Absolute Voltage: Returns the value in actual volts on the specified port.

Example peripherals for analog input are Sharp GP2 Analog Distance Sensors, Pressure Sensors, Light Sensors, Sound Sensors, Color Sensors and reading voltages.

Every digital port of the EZ-B Robot Controller can transmit serial data. Serial Communication is the process of sending data one bit at a time in a sequence. Serial communication is common with many peripherals because it allows commands to be transmitted over one wire. The transmission works similar to morse code.

The Sender and Receiver need to be configured for the baud rate (speed) in which the data will be transmitted. Common baud rate speeds are 300bps, 4800bps, 9600bps, 19200bps, 38400bps, and 57600bps.

Example peripherals for serial communication are LCD Screens, Motor Controllers, Servo Controllers, Computer Communication, Arduino Communication, iRobot Roomba and more.

The I2C is also referred to as the "Two Wire Interface". It is a communication method invented by Philips that is used to communicate with peripherals. The I2C uses two wires for communication, Serial Data Line (SDL) and Serial Clock Line (SCL).

I2C devices can be chained together in a network formation. Each device is given a unique address. The EZ-B V3 has an I2C header which provides both signal wires and power. The EZ-B V2

Example peripherals for I2C communication are LCD Screens, I2C enabled Servos, BlinkM Multicolor LEDs, and more.

Click here for more information on understanding i2c addressing.

Computers are very powerful and contain interfaces that a robot controller could never duplicate, at least not for the price and size. The computer controls the EZ-B over the bluetooth connection. Meanwhile, this opens up a whole world of USB add-ons. The EZ-Builder software supports dozens of USB peripherals ranging from joysticks, cameras and more.