Airelectronics U-Camera, Руководство пользователя

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U-Camera User Manual - Communication Protocol
5
5
Communication Protocol
Communication Protocol
5.1 5.1 Protocol general description Protocol general description
U-Camera communicates using the U-Camera Serial Protocol, UCSP. UCSP is a serial
protocol that allows the controller (indicated as CTRL in this document) to command U-
Camera Gimbal (GMB in this document).
Source Destination Main Function
CTRL(Controller) GMB(U-Camera) Command and configuration
GMB(U-Camera) CTRL(Controller) Status Report and Answer
UCSP is a standard serial protocol at 115200 bps, 1 stop bit and no parity. The
communication messages are based on a standard packet structure defined in the next
Section 5.2.
UCSP
Configuration
Serial Speed Stop bit Parity
115200bps 1 None
The downstream flow (CTRL GMB) is controlled by the master, which decides the packets →
to be sent and when to send them. Although not required, it is recommended to send
periodically (~10Hz at least) packets regarding the command mode and desired
angles/rates.
The upstream flow (GMB CTRL) is handled by U-Camera sending periodically reports of
→
its status. When CTRL sends a request, GMB replays to the request before sending more
periodic reports. The periodic report packets are described in the Section 5.6.
5.2
5.2
Packet structure
Packet structure
The UCSP protocol is based on packets with variable length. The packet structure is
described in the following tables.
0 1 2 3 4 ... N+3 N+4 N+5
SYNC BYTE CATEGORY ID LENGTH PAYLOAD1 ... PAYLOADN CHK_A CHK_B
Position Name Description
0 Synchronization Byte 0xCC Synchronization Byte
1 Category number Upcoming Packet Category
2 Id number Upcoming Packet ID number
3 Packet Length(N) Upcoming data Length
[4, N+3] Payload Payload Content
N+4 Checksum A
N+5 Checksum B
Note that the Packet Length Number is referred to Payload, meaning that the complete
packet is composed by N + 6 bytes.
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