MSP 协议.
MultiWii Serial Protocol
updated 04 July
Multiwii serial protocol was redesigned: MSG协议已经重新设计:
- to be light, as before
- 轻量级
- to be generic: it can be used transparenlty by a GUI, OSD, telemetry or home made config tool.
ie no more specific OSD code should be coded in multiwii - 通用, 有OSD兼容。
- to be bit wire efficient: only requested data are transmitted in a binary format
- 高效，以二进制格式发送。
- to be quite secure: data are sent with a checksum, preventing corrupted configuration to be injected.
- 安全，数据校验码。
- to be header sensitive: as it is designed with a specific header, it can be mixed with other frame, like GPS frame
ie, it will be possible to connect either a GUI or a GPS on the same serial port without changing the conf - 支持头部跟踪。
- to be less sensitive to evolutions:
ie in case of parameter evolution, the main protocol will remain compatible and the GUI will be much less version dependent.
variable data length allows to consider only the beginning of a message, leaving the other octets at the end to extend transparently the message (for instance to add a new PID)
I thought first about an implementation of Mavlink, but I think it's not what Iwas looking for.
Even with a partial implementation, the predefined structures are not lightenough for what I have in mind.
Some messages are however inspired from mavlink structure.
Mavlink 不够轻量级，但是部分结构参考了它。
The main rule remains: Multiwii never sends something on its own.
A request must be done in each case to retrieve or set data.
Each messages received are acknowledged even if there is no data inside.
原则： 在没有数据请求时，飞控不发送任何数据。
There are 2 main messages to consider:
- request message to multiwii
- 请求飞控数据
- multiwii output message
- 飞控返回数据
request message to multiwii
To request simple data without parameters / send a specific command / inject newparameters in multiwii
messages are formated like this:
$M>[data length][code][data][checksum]
1 octet '$'
1 octet 'M'
1 octet '>'
1 octet [data length]
1 octet [code]
several octets [data]
1 octet [checksum]
[data length] can be 0 in case of no param command
multiwii output message
messages are formated like this:
$M>[data length][code][data][checksum]
1 octet '$'
1 octet 'M'
1 octet '>'
1 octet [data length]
1 octet [code]
several octets [data]
1 octet [checksum]
if the message is unknown:
$M|[0][code][checksum]
1 octet '$'
1 octet 'M'
1 octet '|'
1 octet 0
1 octet [unknown code]
1 octet [checksum]
list of message codes
multiwii output message
MSP_IDENT
multitype + version
硬件版本
MSP_STATUS
cycletime & errors_count & sensor present & box activation 周期、错误数、传感器状态、激活状态
MSP_RAW_IMU
9 DOF output 9自由度输出
MSP_SERVO
8 servos 8个舵机
MSP_MOTOR
8 motors 8个舵机
MSP_RC
8 rc chan 8个Futaba遥控通道
MSP_RAW_GPS
fix, numsat, lat, lon, alt, speed GPS数据
MSP_COMP_GPS
distance to home, direction to home 离家距离，离家方向
MSP_ATTITUDE
angles and heading 航向
MSP_ALTITUDE
altitude 高度
MSP_BAT
vbat, powermetersum 电池、功
MSP_RC_TUNING
rc rate, rc expo, rollpitch rate, yaw rate, dyn throttle PID 遥控参数
MSP_PID
table of P I D PID表
MSP_BOX
tabl of checkbox CheckBox
MSP_MISC
powermeter trig 其它
MSP_MOTOR_PINS
which pins are in use for motors & servos, for GUI 电机、舵机对应引脚
MSP_BOXNAMES
the textual aux switch names (it's a way to build a more generic GUI, allowingan easier extension for future checkbox)
MSP_PIDNAMES
the textual PID names PID名称
MSP_WP
get a WP, WP# is in the payload, returns (WP#, lat, lon, alt, flags) WP#0-home,WP#16-poshold
MSP_DEBUG
debug1,debug2,debug3,debug4 variable
multiwiiinput message
MSP_SET_RAW_RC
8 rc chan: it's a way to command multiwii via a "serial RCtransmitter"
MSP_SET_RAW_GPS
fix, numsat, lat, lon, alt, speed: it's a way to inject in multiwii GPS datacoming for instance from an OSD with an integrated GPS
MSP_SET_PID
8 P I D 设置8个PID
MSP_SET_BOX
11 checkbox 设置11个选项
MSP_SET_RC_TUNING
rc rate, rc expo, rollpitch rate, yaw rate, dyn throttle PID 设置遥控选项
MSP_ACC_CALIBRATION
to calibrate ACC 校准ACC
MSP_MAG_CALIBRATION
to calibrate MAG 校准MAG
MSP_SET_MISC
powermeter trig 设置其它
MSP_RESET_CONF
to reset all params to default (new feature) 重置全部参数
MSP_EEPROM_WRITE
to write current params to EEPROM 当前参数保存到EEPROM
===============================================================
原始资料：
[sf]
MSP协议.pdf
(113.04 KB, 下载次数: 95)
[/sf]
| 
发表于 2018-8-18 15:40
