RoverC-Pro I2C Control Protocol

1. Basic Information

Item	Description
Product	RoverC-Pro
SKU	`K036-B`
Bus	I2C, slave mode
I2C Address (7-bit)	`0x38`
Recommended Communication Speed	`100 ~ 400 kHz`
Register Address Width	`8 bit`
Register Data Width	`8 bit`

1.1 Access Permissions

Permission	Description
`R/W`	Read/write
`Reserved`	Reserved; do not access

1.2 General Access Flow

Register Write

The host sends a 1-byte register address followed by the register data:

START + SlaveAddr(W) + RegAddr + Data + STOP

Register Read

The host first writes the 1-byte register address and then reads the register data:

START + SlaveAddr(W) + RegAddr + RESTART + SlaveAddr(R) + Data + STOP

1.3 Data Types and Byte Order

Motor speed uses INT8, with a range of -127 ~ 127.
Servo angle uses UINT8, with a range of 0 ~ 180°.
Servo pulse width uses UINT16, with a range of 500 ~ 2500 us.
Servo pulse width uses big-endian byte order: the high byte is at the lower address and the low byte is at the higher address.

2. Register Overview

Address/Range	Name	Length	Access	Default	Summary	Details
`0x00 ~ 0x03`	Motor Speed	`4`	`R/W`	Not specified	Four-channel motor speed control	`4.1`
`0x10 ~ 0x11`	Servo Angle Control	`2`	`R/W`	Not specified	Two-channel servo angle control	`4.2`
`0x20 ~ 0x23`	Servo Pulse Control	`4`	`R/W`	Not specified	Two-channel servo pulse width control	`4.3`

3. Address Conventions

3.1 Address Regions

Address/Range	Region	Description
`0x00 ~ 0x03`	Motor Control	Four motor speeds
`0x10 ~ 0x11`	Servo Angle Control	Two servo angles
`0x20 ~ 0x23`	Servo Pulse Control	Two servo pulse widths

3.2 Reserved Addresses

All addresses not listed in Section 2 are undefined in the original protocol and must be treated as Reserved. The host must not read or write these addresses or rely on their returned values or write behavior.

4. Register Details

4.1 Motor Speed

Address	Parameter	Type/Range	Access	Description
`0x00`	`Motor1Speed`	`INT8`, `-127 ~ 127`	`R/W`	Motor 1 speed
`0x01`	`Motor2Speed`	`INT8`, `-127 ~ 127`	`R/W`	Motor 2 speed
`0x02`	`Motor3Speed`	`INT8`, `-127 ~ 127`	`R/W`	Motor 3 speed
`0x03`	`Motor4Speed`	`INT8`, `-127 ~ 127`	`R/W`	Motor 4 speed

Positive and negative values select the two rotation directions.
127 and -127 represent the maximum speed in each direction.
0 stops the motor.

4.2 Servo Angle Control

Address	Parameter	Type/Range	Access	Description
`0x10`	`Servo1Angle`	`UINT8`, `0 ~ 180`	`R/W`	Servo 1 target angle in `°`
`0x11`	`Servo2Angle`	`UINT8`, `0 ~ 180`	`R/W`	Servo 2 target angle in `°`

Write a value from 0 ~ 180 to set the target angle of a 180° servo.

4.3 Servo Pulse Control

Address	Parameter	Type	Access	Description
`0x20`	`Servo1PulseHighByte`	`UINT8`	`R/W`	High byte of servo 1 pulse width
`0x21`	`Servo1PulseLowByte`	`UINT8`	`R/W`	Low byte of servo 1 pulse width
`0x22`	`Servo2PulseHighByte`	`UINT8`	`R/W`	High byte of servo 2 pulse width
`0x23`	`Servo2PulseLowByte`	`UINT8`	`R/W`	Low byte of servo 2 pulse width

Combine the pulse width as follows:

pulse_us = (PulseHighByte << 8) | PulseLowByte

The valid range is 500 ~ 2500 us. The default servo control frequency is 50 Hz; 500 ~ 2500 us corresponds to a servo angle of 0 ~ 180°.

For example, to set the servo 1 pulse width to 1500 us:

1500 = 0x05DC
0x20 = 0x05
0x21 = 0xDC

5. Version History

Document Version	Date	Description
`V1.0`	`2026-08-05`	Converted the official RoverC-Pro I2C Control Protocol PDF to structured Markdown without changing the protocol