EZ-B v4 Data Sheet

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EZ-Bv4 Datasheet v0.6

The EZ-Bv4 takes robotics to the next level, with Wi-Fi, Video, Audio capabilities, and the standard features youve come to love from the previous generation EZ-B. The v4 allows your robot to track objects/motion/colors/faces, speak, play music, move servos, read sensors, control H-bridges and more. Connect your Laptop/PC or Mobile device to the EZ-B v4 through an Adhoc or Client connection over Wi-Fi. Both options can be fully configured with the embedded Web Server. The v4 leverages the power and speed of two 32-bit processors (120 MHz ARM Cortex-M3 and 80MHz Microchip PIC32). It is also very expandable with 3 x I2C headers for additional sensors and displays, 24 multi-use Digital I/O, 8 x Analog-to-Digital and Dynamixel servo support. Let the Robot Revolution begin!

Electrical Characteristics

Vin = Battery or DC Power Supply voltage supplied to the board minus the diodes forward voltage drop (0.14 to 0.36V) which is current dependent.
Vcc = regulated by the on-board switching power supply to 3.3VDC.





Voltage input (Vin)




Vin Continuous Current Draw




Vin Current Spikes




Vcc Continuous Current Draw




Vcc Current Spikes




Vin Default Low Battery Warning








Current Draw with No Peripherals




Current Draw with Camera








Digital I/O TTL Voltage Level (input high)




Digital I/O TTL Voltage Level (input low)




Digital I/O TTL Voltage Level (output)




Digital I/O Power Pin Voltage



VDC (Vin)





ADC Voltage level



VDC (5V tolerant)

ADC Power Pin Voltage



VDC (Regulated)





I2C TTL Voltage Level (input/output)




I2C Power Pin Voltage



VDC (Regulated)





UART TTL Voltage Level (input/output)




UART Power Pin Voltage



VDC (Regulated)





Camera Voltage Level (input/output)




Camera Power Pin Voltage



VDC (Regulated)


We learned from the EZ-B v3 to not use voltage regulators on digital I/O of the EZ-B v4. This is because digital ports are generally used for servos. It is very energy inefficient to regulate power for servo motors and therefore generates a lot of heat, kills batteries quickly, etc.. We recommend powering the EZ-B v4 with a 7.4v LiPo battery and therefore the servos do not need regulators. Here is a diagram of regulated and unregulated power pins.


Regulated Power Pins (green):

-           ADC

-           I2c

-           UART

-           Camera

Unregulated Power Pins (blue):

-           Digital I/O



Low Battery Warning

The EZ-B v4 includes a low battery warning feature enabled by default, designed for LiPo batteries. We recommend using LiPo batteries at 7.4v to power the EZ-B v4. The default Vin Battery Warning voltage is 6 VDC. If the EZ-B v4 is powered on with less than 6 VDC, a verbal message will repeat that the battery is low. While the verbal message is repeating, the EZ-B v4 ports will be unresponsive. The battery warning can be disabled in software.

To disable or adjust the minimum voltage of the Low Battery Warning, visit the Connection Control in the EZ-Builder Software. The Configuration Dialog of the Connection Control includes options to disable or adjust the minimum voltage for the Low Battery Warning. The EZ-B v4 must be connected to the software for changes to this setting to take effect.



Hardware Features
Main CPU

         120MHz ARM 32-bit Cortex-M3 CPU

         12-bit ADC

         12-Bit DAC

         CPU internal temperature sensor

         96-bit unique ID

         330 ohm current limiting Resistors on each Digital I/O pin

         Temperature range: -40C to +105C


Fuse Protection

         14A (Resettable) Polyfuse protecting Vin, Battery and Circuit board traces

         500mA Polyfuse protecting STM32 Chip (Green component under the yellow Polyfuse in the lower right)

Note: Polyfuses have an upper temperature limit and will trip (go open) to protect the EZ-B if it gets too hot. If this happens, disconnect the power to allow the EZ-B v4 to cool down and the fuses will reset.




Audio (Amplified)

This is information on the amplification process and how to access the amplified audio for small external speakers.


         Audio amplifier chip output rating: 0.3W max.

         Amplifier in High Pass filter configuration.

         Included Speaker rating: 8ohm 0.5W.

         Via to the upper right of the chip is raw audio from the DAC before the amplification stage.

         Speaker out (amplified audio) pins are left open for an optional external speaker.

Audio (Non-Amplified)

The non-amplified audio can be extracted for those who wish to run their own amplifiers. The pad for the non-amplified audio is directly connected to the DAC of the microcontroller. Be extra cautious when connecting this pin to not short it, or you will risk damaging the microcontroller.




Wi-Fi Specifications

         IEEE 802.11 b/g/n 2.4GHz radio frequency.

         80 MHz 32-bit Processor.

         3.33 Mbps Channel for EZ-B Data.

         3.33 Mbps Channel for Video.

         Certifications: CE, FCC, IC, Japan, South Korea.

         Access Point (AP) & Client modes supported.

         Embedded Web Server.

         WPA2, WPA and WEP encryption.

         Transmit power: +17 dBm.

         Receiver sensitivity: -97 dBm.

         Temperature range: -40C to +85C.


UART Serial Expansion Port

         Asynchronous serial Communication up to 3.75 Mbaud.

         Receive Buffer size: 5kB.

         2.54mm (0.1) Pitch Female header in bottom right corner on board.

         Represents UART0 in software.



Digital I/O Ports

         24 Multi-Use Digital I/O ports: D0-D23

         Software configurable for servos, transmit serial, output 3.3/GND, PWM, and more.

         Input Max 5 VDC TTL Logic.

         Output Max 3.3 VDC TTL Logic

         Special functions:
- D5 can control Dynamixel servos
- D5 (TX) and D6 (RX) can be used as UART1
with 5kB Receive buffer
- D18 (TX) and D19 (RX) can be used as UART2
with 5kB Receive buffer



ADC Input Ports


         8 ADC (Analog-to-Digital) ports: A0-A7.

         0-3.3VDC Range (5V Tolerant).

         Configurable 8-bit (0-255) or 12-bit (0-4095) return values in software.

I2C Ports


         3 x I2C ports (a single bus with 3 ports connected in parallel)

         Software configurable to speeds up to 1000 kHz (default: 100kHz)

         4-pin JST-PH 2.0mm pitch connector

         Pin outs from left to right: GND, 3.3VDC, SDA, SCL

Note: Do not combine 5V and 3.3VDC powered devices as the 3.3VDC SDA and SCL lines may be pulled up to 5V and damage the lower voltage devices.





EZ-Robot Camera Port


         6-pin JST-PH 2.0mm pitch connector.

         This port is proprietary for the EZ-Robot Camera.





Reset Button and LED Feedback


         RGB Wi-Fi Status LED will be white on boot up and blink blue when ready for an Adhoc connection. Will be green when connected to a client network. Will be red when unable to make a connection to client network.

         Reset button resets network settings to default pressed.

         Red Communication LED (below button) flashes with client communication activity.



The EZ-B v4s integrated Wi-Fi has an embedded webserver, DHCP server (for access point mode) and configurable connection modes. The Wi-Fi connection will also use B/G/N modes with WPA, WPA2 and WEB security. When the Reset Button is pressed, the network settings will be reset to the default configuration.

Web Server

To configure the Wi-Fi settings, the EZ-B v4 webserver can be accessed by your web browser. If the EZ-B v4 is in Access Point Mode, the default web address will be If the EZ-B is in Client Mode, you will use the IP Address that EZ-Builder has detected (i.e. http://<ip address>).



Wi-Fi Access Point (AP) Mode

The EZ-B v4 becomes a Wi-Fi Server which allows your device to connect to it. This is the default setting for the EZ-B v4. In this mode, your device (i.e. Computer, iPad, iPhone, etc.) will connect directly to the EZ-B v4 over its Wi-Fi network. You will lose access to the internet if connected this way, unless your device has two network adapters.



Wi-Fi Client Mode

The EZ-B v4 will connect to your existing Wi-Fi network as a client, much like your iPhone, iPad and Computer. When the EZ-B v4 is connected to your Wi-Fi network, you may not know the IP Address that it is assigned. The EZ-Builder software includes a network scan tool which will find all EZ-B v4s on your network.





Power Base

         Red Micro Deans connector: Positive connection recessed, Negative pin protruding.

         2.1mm Barrel Jack Center (Tip) positive voltage input.

         20A ATM automotive fuse protected (pictured).

Note: Use a No. 0 Robertson bit or equivalent flat blade screw driver (diagonally) in order to open the power base to access to the Fuse.



EZ-B Dimensions

All measurements are in millimeters.