Aceinna IMU381 SERIES User manual

IMU381 Series User’s Manual
Doc# 7430-3881-02
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ACEINNA, Inc.
email: [e-mail], website: www.aceinna.com
IMU381 SERIES USER MANUAL
Document Part Number: 7430-3881-02

IMU381 Series User’s Manual
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Doc# 7430-3881-02

IMU381 Series User’s Manual
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Revision History
Date
Document
Revision
Firmware
Applicability
Description
Author(s)
Mar 12,
2018
Rev. 1.0
v19.1.x
Baseline release of IMU381
manual
Feng Liu
Feb 15,
2019
Rev. 2.0
•Update SPI functionality
•This document only describes
usage of the IMU381.
References to other products
have been removed
•Corrections and clarifications
•Removed references to
magnetometer, GPS, and
EKF algorithms, including
some Appendixes
John Newton
Joe Motyka
YiFan Li
David Garnett

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Table of Contents
1Introduction .............................................................................................................................. 1
Manual Overview .............................................................................................................. 1
Overview of the IMU381 Series Inertial Measurement Unit ............................................ 2
2Interface.................................................................................................................................... 3
Electrical Interface ............................................................................................................ 3
2.1.1 Connector and Mating Connector .............................................................................. 3
2.1.2 Power Input and Power Input Ground........................................................................4
2.1.3 Serial Data Interface................................................................................................... 4
2.1.4 Reserved – Factory Use Only..................................................................................... 5
Mechanical Interface ......................................................................................................... 5
3Theory of Operation ................................................................................................................. 6
IMU381 Series Default Coordinate System ...................................................................... 8
3.1.1 Advanced Settings...................................................................................................... 9
IMU381 Theory of Operation ........................................................................................... 9
3.2.1 IMU381 Advanced Settings....................................................................................... 9
3.2.2 IMU381 Built-In Test .............................................................................................. 10
4IMU381 SPI Port Interface Definition ................................................................................... 11
IMU381 Register Map..................................................................................................... 11
IMU381 SPI Register Read Methodology ...................................................................... 13
4.2.1 IMU381 SPI Port Polled-Mode Read....................................................................... 14
4.2.2 IMU381 SPI Port Burst-Mode Read ........................................................................ 15
Output Data Registers ..................................................................................................... 18
System Registers ............................................................................................................. 19
Diagnostic Status Register............................................................................................... 19
IMU381 SPI Register Write Methodology...................................................................... 20
Configuration Registers................................................................................................... 22
4.7.1 Self-Test/Data-Ready............................................................................................... 22
4.7.2 Output Data Rate...................................................................................................... 22
4.7.3 Rate-Sensor Scaling/Low-Pass Filter....................................................................... 23
4.7.4 Accelerometer, and Alternate Rate-Sensor Scaling ................................................. 25
4.7.5 Axis Orientation Settings ......................................................................................... 27
4.7.6 Saving the Configuration to EEPROM ....................................................................27
4.7.7 Hardware and Software Version .............................................................................. 27

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Suggested Operation........................................................................................................ 28
4.8.1 Startup Timing ......................................................................................................... 28
4.8.2 SPI Timing ............................................................................................................... 29
Signal Synchronization.................................................................................................... 30
Bootloader ....................................................................................................................... 31
5IMU381 UART Port Interface Definition .............................................................................. 32
General Settings .............................................................................................................. 32
Number Formats.............................................................................................................. 32
Packet Format.................................................................................................................. 33
5.3.1 Packet Header........................................................................................................... 33
5.3.2 Packet Type.............................................................................................................. 33
5.3.3 Payload Length......................................................................................................... 34
5.3.4 Payload..................................................................................................................... 34
5.3.5 16-bit CRC-CCITT .................................................................................................. 34
5.3.6 Messaging Overview................................................................................................ 34
6IMU381 Standard UART Port Commands and Messages ..................................................... 37
Link Test.......................................................................................................................... 37
6.1.1 Ping Command......................................................................................................... 37
6.1.2 Ping Response .......................................................................................................... 37
6.1.3 Echo Command........................................................................................................ 37
6.1.4 Echo Response ......................................................................................................... 37
Interactive Commands..................................................................................................... 37
6.2.1 Get Packet Request .................................................................................................. 38
6.2.9 Error Response......................................................................................................... 38
Output Packets (Polled)................................................................................................... 38
6.3.1 Identification Data Packet ........................................................................................ 38
6.3.2 Version Data Packet................................................................................................. 39
6.3.3 Test 0 (Detailed BIT and Status) Packet .................................................................. 39
Output Packets (Polled or Continuous) ........................................................................... 40
6.4.1 Scaled Sensor Data Packet 0 .................................................................................... 40
6.4.2 Scaled Sensor Data Packet 1 (Default IMU Data) ................................................... 41
7IMU381 Advanced UART Port Commands........................................................................... 43
Configuration Fields........................................................................................................ 43
Continuous Packet Type Field......................................................................................... 44

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Digital Filter Settings ...................................................................................................... 44
Orientation Field.............................................................................................................. 44
User Behavior Switches .................................................................................................. 46
Commands to Program Configuration............................................................................. 46
7.6.1 Write Fields Command ............................................................................................ 46
7.6.2 Set Fields Command ................................................................................................ 47
Read Fields Command .................................................................................................... 48
Read Fields Response...................................................................................................... 49
Get Fields Command....................................................................................................... 49
Get Fields Response ........................................................................................................ 50
8IMU381 Advanced UART Port BIT ...................................................................................... 51
Built In Test (BIT) and Status Fields .............................................................................. 51
Master BIT and Status (BITstatus) Field......................................................................... 53
hardwareBIT Field .......................................................................................................... 54
hardwarePowerBIT Field ................................................................................................ 54
hardwareEnvironmentalBIT Field................................................................................... 54
comBIT Field .................................................................................................................. 55
comSerialABIT Field ...................................................................................................... 55
comSerialBBIT Field ...................................................................................................... 55
softwareBIT Field............................................................................................................ 56
softwareAlgorithmBIT Field........................................................................................... 56
softwareDataBIT Field .................................................................................................... 56
hardwareStatus Field ....................................................................................................... 56
comStatus Field ............................................................................................................... 57
softwareStatus Field ........................................................................................................ 57
sensorStatus Field............................................................................................................ 57
Configuring the Master Status......................................................................................... 58
8.16.1 hardwareStatusEnable Field..................................................................................... 58
8.16.2 comStatusEnable Field............................................................................................. 58
8.16.3 softwareStatusEnable Field...................................................................................... 58
8.16.4 sensorStatusEnable Field ......................................................................................... 59
9IMU381 BOOTLOADER ...................................................................................................... 60
Updating firmware over UART Interface ....................................................................... 60
9.1.1 Jump to BootLoader Command ............................................................................... 60

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9.1.2 Write APP Command............................................................................................... 60
9.1.3 Jump to Application command ................................................................................ 61
Updating firmware using the SPI Interface..................................................................... 61
9.2.1 Boot Mode Registers................................................................................................ 61
9.2.2 Boot Mode Status Register (0x78) ........................................................................... 62
9.2.3 Boot Command Register (0x7A).............................................................................. 63
9.2.4 Boot Data Register (0x7C)....................................................................................... 64
9.2.5 Boot Loading Sequence ........................................................................................... 64
10 Warranty and Support Information ..................................................................................... 66
10.3.1 Authorization............................................................................................................ 66
10.3.2 Identification and Protection .................................................................................... 66
10.3.3 Sealing the Container ............................................................................................... 67
10.3.4 Marking.................................................................................................................... 67
Appendix A: Installation and Operation of NAV-VIEW .............................................................. 68
NAV-VIEW Computer Requirements ....................................................................................... 68
Install NAV-VIEW ................................................................................................................. 68
Connections................................................................................................................................ 68
Setting up NAV-VIEW .............................................................................................................. 68
Data Recording........................................................................................................................... 69
Data Playback............................................................................................................................. 70
Raw Data Console...................................................................................................................... 70
Horizon and Compass View....................................................................................................... 71
Packet Statistics View ................................................................................................................ 72
Unit Configuration ..................................................................................................................... 72
Advanced Configuration ............................................................................................................ 73
Bit Configuration........................................................................................................................ 74
Read Unit Configuration ............................................................................................................ 76
Appendix B: Sample Packet-Parser Code...................................................................................... 80
Overview .................................................................................................................................... 80
Code listing ................................................................................................................................ 81
Appendix C: Sample Packet Decoding.......................................................................................... 88

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About this Manual
The following symbols are used to provide additional information.
NOTE
Note provides additional information about the topic.
EXAMPLE
This symbol indicates an example that will help the reader understand the terminology.
IMPORTANT
This symbol defines items that have significant meaning to the user
WARNING
The user should pay particular attention to this symbol. It means there is a chance that physical
harm could happen to either the person or the equipment.
This manual uses the following paragraph heading formats:
1 Heading 1
1.1 Heading 2
1.1.1 Heading 3
1.1.1.1 Heading 4
Normal

IMU381ZA Series User’s Manual
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1Introduction
Manual Overview
This manual describes ACEINNA’s IMU381 IMU Inertial Measurement Unit. The IMU381 will
be referred to as “the unit” frequently in this document.
For users wishing to get started quickly, please refer to the two-page quick start guide included
with each evaluation kit shipment. Table 1 highlights the content in each section and suggests
how to use this manual.
Table 1 Manual Content
Manual Section Who Should Read?
Section 1:
Manual Overview
All customers should read sections 1.1 and 1.2.
Section 2:
Interface
Customers designing the electrical and mechanical interface to the IMU381
series products should read Section 2.
Section 3:
Theory of Operation
All customers should read Section 3.
Section 4:
SPI Port Interface
Customers designing the software interface to the IMU381 series products
SPI Port should review Section 4.
Section 5-8:
UART Port Interface
Customers designing the software interface to the IMU381 series products
UART Port should review Sections 5-8.
Section 9:
IMU381 Bootloader
Customers that intend to update Aceinna firmware in the unit should read
this section
Section 10:
Warranty and Support Information
All customers should read Section 10.
Appendix A:
Installation and Operation of NAV-
VIEW
All customers should read Appendix A.
Appendix B:
Sample Packet-Parser Code
All customers that intend to create scripts to interface with serial messages
should read Appendix B
Appendix C:
Sample Packet Decoding
All customers that intend to create scripts to interface with serial messages
should read Appendix C

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Overview of the IMU381 Series Inertial Measurement Unit
This manual describes the use of ACEINNA’s IMU381 and is intended to be used as a detailed
technical reference and operating guide. ACEINNA’s IMU381 Series products combine the latest
in high-performance commercial MEMS (Micro-electromechanical Systems) sensors and digital
signal processing techniques to provide a small, cost-effective alternative to existing IMU
systems.
The IMU381 Series is ACEINNA’s fourth generation of MEMS-based Inertial Systems, building
on over a decade of field experience, and encompassing thousands of deployed units and millions
of operational hours in a wide range of land, marine, airborne, and instrumentation applications.
It is designed for OEM applications.
At the core of the IMU381 Series is a rugged 6-DOF (Degrees of Freedom) MEMS inertial sensor
cluster. The 6-DOF MEMS inertial sensor cluster includes three axes of MEMS angular rate
sensing and three axes of MEMS linear acceleration sensing. These sensors are based on rugged,
field proven silicon bulk micromachining technology. Each sensor within the cluster is
individually factory calibrated for temperature and non-linearity effects during ACEINNA’s
manufacturing and test process using automated thermal chambers and rate tables.
Another unique feature of the IMU381 Series is the extensive field configurability of the units.
This field configurability allows the IMU381 Series of Inertial Systems to satisfy a wide range of
applications and performance requirements with a single mass produced hardware platform. The
basic configurability includes parameters such as baud rate (UART), clock speed (SPI), packet
type, and update rate, and the advanced configurability includes the defining of custom axes.
The IMU381 Series module is packaged in a lightweight, rugged, unsealed metal enclosure that is
designed for cost-sensitive commercial and OEM applications. The unit can be configured to
output data over a SPI Port or a low level UART serial port. The port choice is user controlled by
grounding the appropriate pin on the connector. ACEINNA’s NAV-VIEW 3.X Windows
application supports using the unit low level UART data port NAV-VIEW 3.X is a powerful
Windows-based operating tool that provides complete field configuration, diagnostics, charting of
sensor performance, and data logging with playback.