RunCam Device Protocol

1. Read camera information

Command	ID	Function	Device feature requirements
RCDEVICE_PROTOCOL_COMMAND_GET_DEVICE_INFO	0x00	Read the basic information of the camera, such as firmware version, device type, protocol version	Null

Request packet structure, the length is 3 bytes：

Header	Command ID	crc8
0xCC	0x00	Check code

Response packet structure

Field	Value	Type
Header	0xCC	uint8_t
Protocol Version	Protocol version	uint8_t
Feature	Device feature	uint16_t, Refer to the Feature section for details
crc8	Check code	uint8_t

Feature

Features	Value	Description
RCDEVICE_PROTOCOL_FEATURE_SIMULATE_POWER_BUTTON	1 << 0	Simulation Click the power button
RCDEVICE_PROTOCOL_FEATURE_SIMULATE_WIFI_BUTTON	1 << 1	Simulation Click the Wi-Fi button
RCDEVICE_PROTOCOL_FEATURE_CHANGE_MODE	1 << 2	Switch the device operating mode
RCDEVICE_PROTOCOL_FEATURE_SIMULATE_5_KEY_OSD_CABLE	1 << 3	Simulation 5-key OSD remote control
RCDEVICE_PROTOCOL_FEATURE_DEVICE_SETTINGS_ACCESS	1 << 4	Support access to device settings
RCDEVICE_PROTOCOL_FEATURE_DISPLAYP_PORT	1 << 5	The device is identified as a DisplayPort device by flying controller and receives the OSD data display from the flight controller
RCDEVICE_PROTOCOL_FEATURE_START_RECORDING	1 << 6	Control the camera to start recording video
RCDEVICE_PROTOCOL_FEATURE_STOP_RECORDING	1 << 7	Control the camera to stop recording video
RCDEVICE_PROTOCOL_FEATURE_FC_ATTITUDE	1 << 9	If the device support requests attitude of the remote device(like Betaflight flight controller), it should contain this flag when initializing on the remote device.

2. Camera control

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_CAMERA_CONTROL	0x01	Camera control，For example: through this instruction, send an instruction to simulate the actions of power button to the camera	RCDEVICE_PROTOCOL_FEATURE_SIMULATE_POWER_BUTTON, RCDEVICE_PROTOCOL_FEATURE_SIMULATE_WIFI_BUTTON, RCDEVICE_PROTOCOL_FEATURE_CHANGE_MODE, RCDEVICE_PROTOCOL_FEATURE_START_RECORDING, RCDEVICE_PROTOCOL_FEATURE_STOP_RECORDING

Request packet structure, the length is fixed to 4 bytes：

Header	Command ID	Action ID	crc8
0xCC	0x01	Please refer to the 'Action' section for specific values	Check code

Action

Action	Value	Description
RCDEVICE_PROTOCOL_SIMULATE_WIFI_BTN	0x00	Simulation Click the Wi-Fi button
RCDEVICE_PROTOCOL_SIMULATE_POWER_BTN	0x01	Simulation Click the Power button
RCDEVICE_PROTOCOL_CHANGE_MODE	0x02	Switch the camera mode
RCDEVICE_PROTOCOL_CHANGE_START_RECORDING	0x03	Control the camera to start recording
RCDEVICE_PROTOCOL_CHANGE_STOP_RECORDING	0x04	Control the camera to stop recording

3.Simulate Press command of the 5 key remote control

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_5KEY_SIMULATION_PRESS	0x02	Send the Press event of the 5 key remote control to the camera	RCDEVICE_PROTOCOL_FEATURE_SIMULATE_5_KEY_OSD_CABLE

Request packet structure, the length is fixed to 4 bytes：

Header	Command ID	Action ID	crc8
0xCC	0x02	Refer to the Action section for specific values	Check code

Action

Action	Value	Description
RCDEVICE_PROTOCOL_5KEY_SIMULATION_SET	0x01	Simulate the confirmation key of the 5 key remote control
RCDEVICE_PROTOCOL_5KEY_SIMULATION_LEFT	0x02	Simulate the left key of the 5 key remote control
RCDEVICE_PROTOCOL_5KEY_SIMULATION_RIGHT	0x03	Simulate the right key of the 5 key remote control
RCDEVICE_PROTOCOL_5KEY_SIMULATION_UP	0x04	Simulate the up key of the 5 key remote control
RCDEVICE_PROTOCOL_5KEY_SIMULATION_DOWN	0x05	Simulate the down key of the 5 key remote control

Response packet structure, the length is fixed to 2 bytes：

Header	crc8
0xCC	Check code

4.Simulate Release command of the 5 key remote control

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_5KEY_SIMULATION_RELEASE	0x03	Send the Release event of the 5 key remotre control to the camera	RCDEVICE_PROTOCOL_FEATURE_SIMULATE_5_KEY_OSD_CABLE

Request packet structure, the length is fixed to 3 bytes：

Header	Command ID	crc8
0xCC	0x03	Check code

Response packet structure, the length is fixed to 2 bytes：

Header	crc8
0xCC	Check code

5.Simulate handshake/disconnection command

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_5KEY_CONNECTION	0x04	Send handshake events and disconnected events to the camera	RCDEVICE_PROTOCOL_FEATURE_SIMULATE_5_KEY_OSD_CABLE

Request packet structure, the length is fixed to 4 bytes：

Header	Command ID	Action ID	crc8
0xCC	0x04	Refer to the Action section for specific values	Check code

Action

Action	Value	Description
RCDEVICE_PROTOCOL_5KEY_FUNCTION_OPEN	0x01	Initiate a handshake action to the camera
RCDEVICE_PROTOCOL_5KEY_FUNCTION_CLOSE	0x02	Initiate a disconnection action to the camera

Response packet structure, the length is fixed to 3 bytes：

Header	Action ID + Response result combination	crc8
0xCC	[ (Action ID << 4) + Response result(1：Succes 0：Failure) ]	Check code

 

6.Reuqest attitude of the remote device

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_REQUEST_FC_ATTITUDE	0x50	Request attitude of the flight controller	RCDEVICE_PROTOCOL_FEATURE_FC_ATTITUDE

Request packet structure, the length is fixed to 3 bytes：

Header	Command ID	crc8
0xCC	0x50	Check code

Response packet structure, the length is fixed to 8 bytes：

Header	Roll	pitch	yaw	crc8
0xCC	Type: uint16_t	Type: uint16_t	Type: uint16_	Check code

Device Setting Access

Reserved Setting IDs

Setting	ID	Type	Description	Access Mode
SETTINGID_DISP_CHARSET	0	TEXT_SELECTION	This setting is store current charset of the device	Read & Write
SETTINGID_DISP_COLUMNS	1	UINT8	Read the number of columns displayed on the screen line	Read only
SETTINGID_DISP_TV_MODE	2	TEXT_SELECTION	Read and set the camera's TV mode(NTSC,PAL)	Read & Write
SETTINGID_DISP_SDCARD_CAPACIT	3	STRING	Read the camera's memory card capacity	Read only
SETTINGID_DISP_REMAIN_RECORDING_TIME	4	STRING	Read the remaining recording time of the camera	Read only
SETTINGID_DISP_RESOLUTION	5	TEXT_SELECTION	Read and set the camera's resolution	Read & Write
SETTINGID_DISP_CAMERA_TIME	6	STRING	Read and set the camera's time	Read & Write
RESERVED	7 - 19	-	these setting are reserved	-

6. Get sub settings with special setting ID

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_GET_SETTINGS	0x10	get a sub settings info with special parent setting id，including setting name, type and current value(in string format)	RCDEVICE_PROTOCOL_FEATURE_DEVICE_SETTINGS_ACCESS

Request packet structure, the length is fixed to 5 bytes：

Header	Comman ID	setting ID	Chunk Index	crc8
0xCC	0x10	Retrieve the sub settings through the parent setting ID	chunk index	Check code

Response packet structure，the length is not fixed:

Field	Value	Size
Remaining Chunk	remaining chunk count	uint8_t
Data Length	The length of data from current field to the CRC field. This length does not include the current field and the CRC field
Setting ID	unique id (Relative to the entire setting tree)	uint8_t
Setting name	setting name	char[], a null-terminated string
Setting value	value of setting	char[], a null-terminated string
Setting ID	unique id (Relative to the entire setting tree)	uint8_t
Setting name	setting name	char[], a null-terminated string
Setting value	value of setting	char[], a null-terminated string
...	...	...
...	...	...
crc	crc8 code	uint8_t

7. Read a setting detail

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_READ_SETTING_DETAIL	0x11	Retrieve the detail of setting, e.g it's maybe including max value, min value and etc. This command can not be called for the setting type with Folder and Static	RCDEVICE_PROTOCOL_FEATURE_DEVICE_SETTINGS_ACCESS

Request packet structure, the length is fixed to 5 bytes：

Header	Comman ID	Setting ID	Chunk Index	crc8
0xCC	0x11	setting ID	Chunk Index	Check code

Response packet structure，the length is not fixed:

Field	Size	Description
Remaining Chunk	remaining chunk count	uint8_t
Data length	uint8_t	The length of data from current field to the CRC field. This length does not include the current field and the CRC field
setting type	uint8_t	the type of setting，refer to 'setting type' section to know more
value	current value, the size is depending on setting	the current value of setting
min value	the size is depending on setting	max value
max value	the size is depending on setting	min value
decimal point	uint16_t	the digtal count after decimal point
step size	the size is depending on setting	the increment/decrement value when modifying the setting
max string size	uint8_t	max size of string
text_selections	char[]	a null-terminated string，the content is all available string in the setting, they are separated by a semicolon(;)
crc	uint8_t	crc8 code

setting type

available setting type	setting id
UINT8	0
INT8	1
UINT16	2
INT16	3
FLOAT	8
TEXT_SELECTION	9
STRING	10
FOLDER	11
INFO	12

INTEGER

when setting type is UINT8, INT8, UINT16 or INT16，the min value, max value, step size will be returned from Device，and the size of min value, max value and step size are depending on their setting type, e.g if the setting type is UINT8, then min value and max value are uint8_t.

FLOAT

min value, max value, decimal point, step size will be returned, the type of step size is int32_t

TEXT_SELECTION

text_selections will be returned as a null-terminated string, the content is all available string in the setting, they are separated by a semicolon(;)

STRING

max string size will be returned, it's used to limit the max size of the string when user editing it.

FOLDER

If the setting type is FOLDER, means it contains a set of settings. This setting can't be modified, when you call Get Detail Command(0x7) with it, it will return a empty response and the error code won't be zero.

INFO

if the settings type is INFO，this field is same with FOLDER, can't be modified.

COMMAND

not design yet

8. Write a setting

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_WRITE_SETTING	0x13	change the value of special setting，can't call this command with the setting type of FOLDER and INFO	RCDEVICE_PROTOCOL_FEATURE_DEVICE_SETTINGS_ACCESS

Request packet structure, the length is not fixed：

Header	Command ID	Setting ID	value	crc8
0xCC	0x13	setting ID	value of the setting, size is depending on setting type	Check code

INTEGER

when setting type is UINT8, INT8, UINT16 or INT16，the value type is integer, the difference is the size, e.g if the setting type is UINT8, the vlaue field size is uint8_t, same with others.

FLOAT

a null-terminated string, it describing a float value

TEXT_SELECTION

the index in text_selections that point to new value.

STRING

a null-terminated string

COMMAND

not design yet

Response packet structure，the length is fixed to 4 bytes:

Field	Size	Description
result code		uint8_t
update menu items	uint8_t	if the value of this field is not zero, the FC size should resend the RCDEVICE_PROTOCOL_COMMAND_GET_SETTINGS(0x10) to retrieve the settings of current page.
crc	uint8_t	crc code

9. Fill screen area

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_DISP_FILL_REGION	0x20	Fill a area with a special char

Request packet structure, the length is not fixed：

Header	Comman ID	x	y	width	height	character	crc8
0xCC	0x20	x	y	width	height	the character that going to fill the area	Check code

10. write a single character

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_DISP_WRITE_CHAR	0x21	Write a character at special position

Request packet structure, the length is not fixed：

Header	Comman ID	x	y	character	crc8
0xCC	0x21	x	y	the character that going to draw	Check code

11. Write a string horizontally

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_DISP_WRITE_HORT_STRING	0x22	Write a character at special horizontal position

Request packet structure, the length is not fixed：

Header	Comman ID	string length	x	y	string	crc8
0xCC	0x22	the length of string(60 is max length)	x	y	the string that going to draw	Check code

12. Write a string vertical

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_DISP_WRITE_VERT_STRING	0x23	Write a character at special vertical position

Request packet structure, the length is not fixed：

Header	Comman ID	string length	x	y	string	crc8
0xCC	0x23	the length of string(60 is max length)	x	y	the string that going to draw	Check code

13. Write a chars

Command	ID	Function	Camera feature requirements
RCDEVICE_PROTOCOL_COMMAND_DISP_WRITE_CHARS	0x24	Write a character at special position

Request packet structure, the length is not fixed：

Header	Comman ID	data length	data	crc8
0xCC	0x24	the length of data(60 is max length)	The data is used to draw different characters at one or more locations, each of which needs to occupy 3 bytes, which is x, y, char. Allows up to 20 sets of data, that means the maximum length can not exceed 60 bytes.	Check code

 

 

CRC checksum implementation

uint8_t crc8_dvb_s2(uint8_t crc, unsigned char a)
{
    crc ^= a;
    for (int ii = 0; ii < 8; ++ii) {
        if (crc & 0x80) {
            crc = (crc << 1) ^ 0xD5;
        } else {
            crc = crc << 1;
        }
    }

    return crc;
}