Motus Reference Manual
Page 101 of 146
Version 1.1
29/11/2019
16 Advanced Navigation Packet Protocol
The Advanced Navigation Packet Protocol (ANPP) is a binary protocol designed with
high error checking, high efficiency and safe design practices. It has a well defined
specification and is very flexible. It is used across all existing and future Advanced
Navigation products.
16.1
Data Types
The following data types are used in the packet protocol. All data types in the protocol
are little endian byte ordering.
Abbreviation Bytes
Also known as
u8
1
unsigned char, unsigned byte, uint8_t
s8
1
char, byte, int8_t
u16
2
unsigned short, uint16_t
s16
2
short, int16_t
u32
4
unsigned int, unsigned long, uint32_t
s32
4
int, long, int32_t
u64
8
unsigned long long, uint64_t
s64
8
long long, int64_t
fp32
4
float
fp64
8
double
Table 28: Data type abbreviations used in the ANPP
16.2
Packet Structure
The ANPP packet structure is shown in Table 29 and the header format is shown in
Table 30. Example code can be downloaded from the software section.
Header
Header LRC
Packet ID
Packet Length
CRC16
Packet Data
Table 29: ANPP Packet Structure
ANPP Header Format
Field
#
Bytes
Offset
Data
Type
Size
Description
1
0
u8
1
Header LRC, see section 16.2.1
2
1
u8
1
Packet ID, see section 16.2.2
3
2
u8
1
Packet Length, see section 16.2.3
