The Seed Robotics smart actuators run Seed Robotics own firmware that is developed in paralel and as part of the EROS architecture.

At present, the micro28, micro57, mini67 and micro448 actuator models are used in different Seed Robotics models.

The control table below applies to all of them. As part of the EROS initiative commitment, we wish that all our hardware is exposed and controlled by the user under one single command and control architecture.

The control table entries are either of WORD type (2 bytes) or BYTE type (1 byte) depending in the range of values they handle.

A BYTE value is written directly to the memory position.

A WORD value however is written in Little Endian style, that is you must break the word in two bytes. The Low order byte mus be written first, to the memory address shown in the control table, followed by the high byte:
[ADDRESS AT CONTROL TABLE] LOW BYTE
[ADDRESS AT CONTROL TABLE + 1] HIGH BYTE

In pseudo code, it would be:

# PSEUDO CODE. Writing a WORD value 
word OUT_VALUE = 2048

uart_write_byte(OUT_VALUE & 0xFF)
uart_write_byte((OUT_VALUE << 8) & 0xFF)

It is also important to note that WORD values should be written in one single WRITE command.
Splitting the WRITE of a WORD value in two individual commands, and sending it as individual Bytes, is unsupported and will yield incorrect results: the first command with the LOW byte is discarded; the next command with the HIGH byte is processed and assumes a low byte of 0 since the low byte was not included in the second command.
Therefore writing WORD values should be done in one single command that will include both the LOW and HIGH bytes simultaneously.

For more information on how to WRITE to the control table see the protocol documentation: you can do it using the Dynamixel Protocol or the STP Protocol.

All memory positions are typically readable.

READing from a memory position will return the state of that variable at the time of processing the READ request.
Here are a few examples of READING the control table:

• If you have set Torque Enable (position 24) to Off (0), you can query the Present Position (memory position 36) while you move the joint with your hand. You will see the values being updated in real time. This technique can be used to capture key frames for example.
• If you have set a Target Position (memory position 30), you can read memory positions 36 (Present position), 38 (Present speed) and 46 (Moving) to check if the trajectory is being followed. This is especially useful for detecting the arrival at the target or detecting anomalies such as stalling, normally due to external physical blockage

WRITing to a memory position will usually either configure a parameter or trigger an action.

As an example:

• To make the servo move to a specific position, WRITE your target to the memory position 30 (Target Position). If Torque is not enabled, it will be automatically enabled and servo will seek the Target position.
• If you wish to control the moving speed, you may WRITE to the memory position 32 (Target Speed) prior to setting your target position.

For more information on how to READ and WRITE to the control table see the protocol documentation: you can do it using the Dynamixel Protocol or the STP Protocol.