Overview

The OpenRB-150 is a new open source Arduino compatible embedded controller.

The controller features the same pinout and the form factor as the Arduino MKR to ensure compatibility with physical accessories, and has support for programming using the Arduino IDE.

The OpenRB-150 also features 4 dedicated DYNAMIXEL ports, and supports the DYNAMIXEL Wizard 2.0 testing and calibration software.

note

NOTE : Specialty firmware is required to utilize the OpenRB-150 with DYNAMIXEL Wizard. This firmware is included in the OpenRB board manager package.

Specifications

Item	Specification
MICROCONTROLLER	SAMD21 Cortex-M0+ 32bit low power ARM® MCU
BOARD POWER SUPPLY	(USB 3.0) 5 V (VIN -or Terminal) 3.7 ~ 12.6 V
SUPPORTED BATTERY	Li-Po 1 - 3 cell (3.7 - 11.1 V) XT60 connector ready
DC CURRENT FOR 3.3V PIN	Max 300 mA
DC CURRENT FOR 5V PIN	Max 300 mA (Before change) Max 150 mA (After change)
DC CURRENT FOR DYNAMIXEL PORTs	3,000 mA
CIRCUIT OPERATING VOLTAGE	3.3 V
DIGITAL I/O PINS	24
PWM PINS	12 (0, 1, 2, 3, 4, 5, 6, 7, 8, 10, A3 - or 18 -, A4 -or 19)
UART	2
SPI	1
I2C	1
ANALOG INPUT PINS	7 (ADC 8/10/12 bit)
ANALOG OUTPUT PINS	1 (DAC 10 bit)
EXTERNAL INTERRUPTS	10 (0, 1, 4, 5, 6, 7, 8, A1 -or 16-, A2 - or 17)
DC CURRENT PER I/O PIN	7 mA
FLASH MEMORY	256 KB
FLASH MEMORY FOR BOOTLOADER	8 KB
SRAM	32 KB
EEPROM	no
CLOCK SPEED	32.768 kHz (RTC), 48 MHz
LED_BUILTIN	3
DYNAMIXEL TTL Port 1	4 (Max 1 Mbps)
Board Dimensions	25 x 66 mm
Supported Software	Arduino IDE, DYNAMIXEL Wizard 2.0
Supported DYNAMIXEL2	X Series, MX Series, AX Series, P Series

1

Baud Rate	Margin od Error
1M [bps]	0.000 [%]
115,200 [bps]	-0.160 [%]
57,600 [bps]	-0.160 [%]
9,600 [bps]	0.000 [%]

1 RS-485 models will require DYNAMIXEL Communication Bridge to convert TTL to RS-485.

2 24V models require a separate power connection.

note

NOTE: The 5V regulator has been updated as of 2024, resulting in a modification to the DC current (5V) value from 300mA to 150mA.

danger

• The current from the USB port is limited to 500mA with the built-in fuse, but a high current draw may cause damage to USB ports used to power the OpenRB-150.
• For applications requiring rapid movement or high torque, use of the terminal block to supply power is recommended.
• Always confirm the operating voltage of your DYNAMIXEL modules before connecting them to the OpenRB-150.
• The maximum voltage that the I/O pins can tolerate is 3.3V. Applying voltages higher than 3.3V to any I/O pin could damage the board.
• Do not connect or disconnect DYNAMIXEL actuator cables while power is being supplied.

danger

DANGER
(Ignoring these warnings may cause serious injury or death)

• Never place items containing water, flammables/open flames, or solvents near the product.
• Never place fingers, arms, toes, and other body parts near product during operation.
• Cease operation and remove power from the product if the product begins to emit strange odors, noises, or smoke.
• Keep product out of reach of children.
• Check input polarity before installing or energizing wiring or cables.

warning

CAUTION
(Ignoring these warnings may cause mild injury or damage to the product)

• Do not insert blades or other sharp objects during product operation.

warning

ATTENTION
(Ignoring these warnings may cause minor injury or damage to the product)

• Do not disassemble or modify the product.
• Do not drop the product or apply strong impacts.
• Do not connect or disconnect DYNAMIXEL cables while power is being supplied.

Hardware Layout

Pinout

Reset Button

Pressing the Reset Button hard reboots the microcontroller, double pressing the Reset Button reboots the microcontroller into bootloader mode.

The OpenRB-150 will not load it's Arduino sketch(or firmware) when in bootloader mode.

warning

WARNING
Resetting the microcontroller will also reset the power of any connected DYNAMIXELs (Power Switch).

It is important to only reset the microcontroller when the acutators are in a safe postion, to avoid possible damage or injury when the acuators are reset.

DYNAMIXEL Power Switch

Power to the DYNAMIXEL ports is controlled by the FET on the bottom of the microcontroller.

The FET can enable and disable the power to the connected ports, by default the FET is turned off whenever the OpenRB-150 is powered on.

When the FET is turned on, the DXL RED LED will also be turned on to confirm the power supply status.

Terminal VIN

The included terminal block provides compatiblity with a wide range of input power sources.
ROBOTIS recommends using the terminal block to supply power when possible.

To supply power to the OpenRB-150 controller via the Terminal VIN, set the jumper to VIN(DXL) side as shown below.

Terminal VIN jumper setting

Power input circuitry

warning

CAUTION
Do not charge the battery when connected to the controller.

XT60 Connector

The XT60 connector is widely used in the RC products and it can be assembled on the back of the OpenRB-150 controller.
Please remove the Terminal Block before soldering the XT60 right angle connector.

XT60 Connector Ready

Power Source Jumper

OpenRB-150 can be powered with three sources.
In order to properly supply power to the controller and DYNAMIXEL, the power source jumper needs to be set properly.

When using USB or VIN	When using Terminal Block or XT60

DYNAMIXEL Ports

4 DYNAMIXEL Ports are ready for any TTL supported DYNAMIXEL.

Item	TTL
Pinout	1 GND 2 VDD 3 DATA
Diagram
Housing	JST EHR-03
PCB Header	JST B3B-EH-A
Crimp Terminal	JST SEH-001T-P0.6
Wire Gauge for DYNAMIXEL	21 AWG

note

NOTE: Above circuit is designed for 5V or 5V tolerant MCU. Otherwise, use a Level Shifter to match the voltage of MCU.

RS-485 supported DYNAMIXEL can also be used when connected with the DYNAMIXEL Communication Bridge.

DYNAMIXEL Communication Bridge

Serial Port

The Serial Port assigned to Serial2 can be used to connect various devices for debugging the code or controlling the controller.

LEDs

Three LED indicates the status of the OpenRB-150 controller.

• PWR (Green) : This LED is turned on whenever the OpenRB-150 is powered.
• USER (Orange) : This LED can be controlled by user via Pin 32 or LED_BUILTIN in the Arduino sketch code.
• DXL (Red) : This LED will be turned on when the DYNAMIXEL port is powered on.

Pin Name Definitions

// Battery
#define ADC_BATTERY	(33u)

// LEDs
#define PIN_LED     (32u)
#define LED_BUILTIN PIN_LED

// DYNAMIXEL POWER FET
#define BDPIN_DXL_PWR_EN  (31u)

Connecting Power

OpenRB-150 controller can be powered with three power sources.

USB C

VIN

Terminal VIN

danger

WARNING

1. Always check the polarity of any power supplies before connecting them to the OpenRB-150.
   Incorrect polarity can permanently damage the microcontroller.

2. Make sure to set the Jumper correctly depending on the power source.

Connection Examples

When running 5V DYNAMIXEL with the USB power

danger

WARNING
For applications that require high velocity or torque, please supply power via Terminal VIN.
USB port is not a suitable power source for dynamic motor operation.
Drawing excessive power from the USB port may cause reboot or damage on the PC.
Using an external power source is recommended as shown below.

When running 12V TTL DYNAMIXEL

When running 12V RS-485 DYNAMIXEL

Development Environment

DYNAMIXEL Wizard 2.0

OpenRB-150 supports DYNAMIXEL Wizard 2.0.
In order to configure and manage DYNAMIXEL with DYNAMIXEL Wizard 2.0, please upload the usb_to_dynamixel sketch in the OpenRB-150 board manager example.

note

NOTE
usb_to_dynamixel sketch is uploaded to the OpenRB-150 as a factory default firmware.
Up to 1 Mbps baudrate is supported with usb_to_dynamixel sketch.

Connect the USB C cable to OpenRB-150 and Upload the usb_to_dynamixel sketch

OpenRB-150 supports most features of DYNAMIXEL Wizard 2.0 including testing DYNAMIXEL, firmware management, packet analyzing, data plotting, control table backup, etc.

Various baudrates up to 1 Mbps are supported

DYNAMIXEL Firmware Recovery and Update are supported

Graphing feature is supported

Analyzing DYNAMIXEL packet is supported

Install the Arduino IDE

Installl on Linux

1. Download the Linux 64 bit version of Arduino IDE from the official Arduino download page.
   https://www.arduino.cc/en/software

2. Extract the downloaded file to the desired folder and execute the install script as below in the terminal.

$ ./install.sh

3. To run the Arduino IDE on Linux platform, enter the command below in the terminal.

$ arduino

Install on Mac

1. Download the Mac OS X version of Arduino IDE from the official Arduino download page.
   https://www.arduino.cc/en/software

2. Drag the downloaded Arduino file into the Applications.

3. Run the Arduino IDE.

Install on Windows

1. Download the Windows Installer version of Arduino IDE from the official Arduino download page.
   https://www.arduino.cc/en/software

2. Install the downloaded file.

3. Run the Arduino IDE.

Please refer to Arduino Software Installation instruction video

Install Board Manager

On the Arduino IDE, go to File > Preferences from the top menu.
When the Preferences window appears, copy and paste following address in the Additional Boards Manager URLs textbox.

https://raw.githubusercontent.com/ROBOTIS-GIT/OpenRB-150/master/package_openrb_index.json

Arduino SAMD Board Manager

The OpenRB-150 requires Arduino SAMD board manager for building and uploading sketches to the controller. Follow the instructions below to install the Arduino SAMD Board Manager.

1. Go to Tools > Board > Boards Manager.
2. Search for Arduino SAMD and Install the latest version.

OpenRB-150 Board Manager

Follow the instructions below to install the OpenRB-150 Board Manager.

1. Go to Tools > Board > Boards Manager.
2. Search for OpenRB and Install the latest version.

Library API

There are three ways to add libraries to the Arduino IDE.

• Using the Library Manager
• Importing a .zip Library
• Manual installation

Each way is described in detail in the Arduino Official Guide, so please refer to it if necessary.
Below is an example of using the Library Manager.

Search for DYNAMIXEL2Arduino from the Library Manager and install the library.

If the DYNAMIXEL2Arduino library has been successfully installed, useful examples to control DYNAMIXEL can be found under the DYNAMIXEL2Arduino category.

Dynamixel2Arduino Library

Dynamixel2Arduino Class

• begin()
• getPortBaud()
• ping()
• scan()
• getModelNumber()
• setID()
• setProtocol()
• setBaudrate()
• torqueOn()
• torqueOff()
• ledOn()
• ledOff()
• setOperatingMode()
• setGoalPosition()
• getPresentPosition()
• setGoalVelocity()
• getPresentVelocity()
• setGoalPWM()
• getPresentPWM()
• setGoalCurrent()
• getPresentCurrent()
• getTorqueEnableStat()
• readControlTableItem()
• writeControlTableItem()

Master Class

DYNAMIXEL2Arduino class inherits below public functions from the Master class.

• read()
• write()
• syncRead()
• syncWrite()
• bulkRead()
• bulkWrite()
• getLastLibErrCode()

Upload Sketch

Uploading a sketch to the OpenRB-150 is similar with Arduino controllers.
Connect the OpenRB-150 to the PC via USB cable, select the OpenRB-150 board and the port that is connected to the OpenRB-150, then click on the Upload icon.

note

Note If error occurs during the Upload process, please try uploading the sketch in the bootloader mode by double clicking the Reset Button.

Downloads

• OpenRB-150 BOM (BOM)
• OpenRB-150 Schematic (PDF)
• OpenRB-150 2D Drawing (PDF, DWG)
• OpenRB-150 3D Modeling (STL, STEP)
• OpenRB-150 Gerber (GBR)
• OpenRB-150 Board Manager (GitHub Repo)
• DYNAMIXEL2Arduino Library (GitHub Repo)