Information provided herein is considered accurate however is not guaranteed. Memsense reserves the right to change specifications at any time, without notice.
Document Number
DOC00290
Document Revision
J
Page 6
Graphically, the sample has the format shown in Figure 3:
Figure 3 - Sample structure
The complete structure of a sample is detailed in Table 3.
Table 3 - Sample Element Descriptions
BYTE
ELEMENT
DESCRIPTION
0 - 3
Synchronization bytes
each byte encoded as 0xFF hex
4
Message size
Size in bytes of entire data packet including complete header
5
Reserved
6
Message ID
Type of message. Data messages with MID = 0x14 hex (20 decimal).
7-8
Sample Timer
Bytes 7 (MSB) and 8 (LSB) when combined represent a 16-bit timer
value of the time at which the ADC started the conversion for the X
Gyro with a scale of 2.1701 x 10
-6
seconds/count.
9-10
Reserved
11-12
Serial Number
Unique number identifying each device
15
Payload
The payload size is calculated as follows:
payload size = message size – 13(header) – 1(Checksum byte)
37
Checksum Byte
8-bit checksum byte. Sum sample contents ( payload). DO
NOT include the checksum byte. The summed value should equal the
checksum if the message is valid. If larger than 8-bit addition is used to
calculate the checksum, the checksum will be the remainder of a divide
by 256.
