Description of the OpenCM9.04-A control board for Dynamixel servomotors:
The OpenCM9.04-A control board for Dynamixel servomotors is an embedded board based on ARM Cortex-M3 32bit CPU.
The board comes in 2 flavours: The OpenCM9.04-A control board for Dynamixel servomotors which is simply the PCB with SMD components (no connectors, switches or headers pre soldered) and the OpenCM9.04-B control board for Dynamixel servomotors (An end-of-life product) which comes with all 3pin connectors pre soldered and switches ready to use. Type B boards also come with headers that users can optionally solder in case they wish to access the additional GPIO pins on the edges of the board.
Also, the OpenCM9.04 is a platform with open-source hardware and software. Based on Processing and Wiring languages the ROBOTIS OpenCM, an Arduino-like IDE that allows the user to easily program in C/C++, facilitates robot development with ease. ROBOTIS OpenCM is supported in Windows, Linux and MacOS computer platforms.
Package content of the OpenCM9.04-A control board for the Dynamixel servomotors
- 1 x OpenCM9.04 control board for the Dynamixel servomotors
- 1 x User guide
Main parts of the OpenCM9.04-A control board for the Dynamixel servomotors

- Power Switch: Battery connection
- Battery socket: sockets to connect Li-Ion Battery(ies). [Note: each battery provides 3.7V; batteries in both pins provide 7.4V]
- DYNAMIXEL TTL BUS: ports for TTL-based Dynamixels
- USART PIN: connect 4-pin devices such as the BT110A bluetooth communication module, BT-210, Zigbee communication kit for Bioloid robots, LN-101 USB Downloader(note: the LN-101 firmware only allows communications with the PC).
- User Switch: user-programmable switch; OpenCM9.04 recovery-mode
- Analog Reference Selection Jumper : change to 5V for analog signals
- Micro-B USB: Connect the OpenCM9.04 for communications, downloads, and 5V input power supply. Any type-B micro USB cable for Android phone is useful
- Status LED: Test LED for OpenCM9.04’s programming. The LED blinks with a high/low signal to pin D16
- Reset switch: resets the CPU
- JTAG/SWD 4 PIN: Via JTAG/SWD terminal implement other programs such as IAR, Keil
- External Sensor PIN: pins for Robotis’ Robotis’ sensors.
- 2.54 mm GPIO Header: Interface external devices to the OpenCM9.04 control board's CPU
Notice regarding the OpenCM9.04-A control board for the Dynamixel servomotors:
- OpenCM 9.04-A is a board-only product for DIY developers. Users will need to purchase the OpenCM9.04-Accessory Set and solder the product themselves to make it into a usable, full product. Please purchase OpenCM9.04-B if you're looking for the full, ready to use product
- The OpenCM9.04 is not supported by RoboPlus, but supported by ROBOTIS OpenCM program
- The input voltage of the XL-series is 7.4V
- When using the OpenCM-9.04 to control the Dynamixel,a separate power supply must be supplied to the Dynamixel