acconeer a121-v1.3.0 Presence Detector User Guide

acconeer a121-v1.3.0 Presence Detector

Product Information

Specifications:

• Product Name: I2C Presence Detector
• Manufacturer: Acconeer AB
• Version: a121-v1.3.0
• Date: October 6, 2023

FAQs

• Q: How to troubleshoot if the detector is not responding?
  A: If the detector is not responding, try the following steps:

1. Check the connections.
2. Verify power supply.
3. Refer to the troubleshooting section in the user manual.

• Q: Can the detector be used outdoors?
  A: The detector is designed for indoor use only and may not function correctly outdoors due to environmental factors.

Acconeer SDK Documentation Overview

To better understand what SDK document to use, a summary of the documents are shown in the table below.

Table 1: SDK document overview.

RSS API documentation (html)
rss api| The complete C API documentation.| –  RSS application implementation

–  Understanding RSS API functions

User guides (PDF)
A121 Assembly Test| Describes the Acconeer assembly test functionality.| – Bring-up of HW/SW –  Production test implementation
A121 Breathing Reference Application| Describes the functionality of the Breathing Reference Application.| – Working with the Breathing Reference Application
A121 Distance Detector| Describes usage and algorithms of the Distance Detector.| – Working with the Distance Detector
A121 SW Integration| Describes how to implement each integration function needed to use the Acconeer sensor.| – SW implementation of custom HW integration
A121 Presence Detector| Describes usage and algorithms of the Presence Detector.| – Working with the Presence Detector
A121 Smart Presence Reference Application| Describes the functionality of the Smart Presence Reference Application.| – Working with the Smart Presence Reference Application
A121 Sparse IQ Service| Describes usage of the Sparse IQ Service.| – Working with the Sparse IQ Service
A121 Tank Level Reference Application| Describes the functionality of the Tank Level Reference Application.| – Working with the Tank Level Reference Application
A121 STM32CubeIDE| Describes the flow of taking an Acconeer SDK and integrate into STM32CubeIDE.| – Using STM32CubeIDE
A121 Raspberry Pi Software| Describes how to develop for Raspberry Pi.| – Working with Raspberry Pi
A121 Ripple| Describes how to develop for Ripple.| – Working with Ripple on Raspberry Pi
XM125 Software| Describes how to develop for XM125.| – Working with XM125
I2C Distance Detector| Describes the functionality of the I2C Distance Detector Application.| – Working with the I2C Distance Detector Application
I2C Presence Detector| Describes the functionality of the I2C Presence Detector Application.| – Working with the I2C Presence Detector Application
Handbook (PDF)
Handbook| Describes different aspects of the Acconeer offer, for example radar principles and how to configure| –  To understand the Acconeer sensor

–  Use case evaluation

Readme (txt)
[README| Various target specific information and links| – After SDK download

I2C Presence Detector Application

The I2C Presence Detector is an application that implements the Acconeer Presence Detector with a register based I2C interface.

The functionality of the presence detector is described in A121 Presence Detector User Guide.pdf or in Acconeer Docs.
Note: Some of the registers like start and end have a different unit in the I2C Presence Detector, millimeters instead of meters, to make it easier to handle the register values as integers.

Usage
The module must be ready before the host starts I2C communication.

• The module will enter ready state by following this procedure.
  • Set WAKE UP pin of the module HIGH.
  • Wait for module to be ready, this is indicated by the MCU INT pin being HIGH.
  • Start I2C communication.
• The module will enter a low power state by following this procedure.
  • Wait for module to be ready, this is indicated by the MCU INT pin being HIGH.
  • Set the WAKE UP pin of the module LOW.
  • Wait for ready signal, the MCU INT pin, to become LOW.

1. Read Detector Status
   The status of the module can be acquired by reading the Detector Status register, The most important bits are the Busy and Error bits.
   The Busy bit must not be set when a new command is written. If any of the Error bits are set the module will not accept any commands except the RESET MODULE command.

2. Writing a command
   A command is written to the Command register. When a command is written the Busy bit in the Detector Status register is set and it will be cleared automatically when the command has finished.

3. Setup and Start Detector
   Before the module can perform presence detection it must be configured. The following steps is an example of how this can be achieved.
   Note: The configuration parameters can not be changed after a APPLY CONFIGURATION command. If reconfiguration is needed the module must be restarted by writing RESET MODULE to the Command register.

   • Power on module
   • Read Detector Status register and verify that neither Busy nor Error bits are set.
   • Write configuration to configuration registers, for example Start register and End register.
   • Write APPLY CONFIGURATION to Command register.
   • Poll Detector Status until Busy bit is cleared.
   • Verify that no Error bits are set in the Detector Status register.
   • Write START DETECTOR to Command register.
   • Poll Detector Status until Busy bit is cleared.
   • Verify that no Error bits are set in the Detector Status register.
   • Read Detector Result register
   • If PRESENCE DETECTED is set presence is currently detected.
   • If PRESENCE DETECTED STICKY is set presence has been detected since last read.
   • If DETECTOR ERROR is set an error has occurred, restart module with the RESET MODULE command.
   • If presence was detected, the presence distance can be read in the Presence Distance register.

4. Stop and Restart Detector
   The detector can be stopped and restarted.

   • The following steps is an example of how to stop the detector.
   • Read Detector Status register and verify that neither Busy nor Error bits are set.
   • Write STOP DETECTOR to Command register.
   • Poll Detector Status until Busy bit is cleared.
   • Verify that no Error bits are set in the Detector Status register.
   • The following steps is an example of how to re-start the detector.
   • Read Detector Status register and verify that neither Busy nor Error bits are set.
   • Write START DETECTOR to Command register.
   • Poll Detector Status until Busy bit is cleared.
   • Verify that no Error bits are set in the Detector Status register.

Advanced Usage

1. Debug UART logs
   UART logging can be enabled on the DEBUG UART by writing ENABLE UART LOGS to the Command register.
   The detector configuration can be logged on the UART by writing LOG CONFIGURATION to the Command register.
   UART logging can be disabled by writing DISABLE UART LOGS to the Command register.

2. Reset Module
   The module can be restarted by writing RESET MODULE to the Command register.
   After the restart the detector must be configured again.

3. Presence Detection on GPIO
   The I2C Presence Detector can be configured to set MISC GPIO0 pin HIGH when presence is detected, and LOW when presence is not detected. To enable presence detection on GPIO, write 1 to the Detection On Gpio register. To disable presence detection on GPIO, write 0 to the Detection On Gpio register.

Register Protocol

I2C Slave Address
The default slave address is 0x52.

Protocol Byte Order
Both register address, 16-bit, and register data, 32-bit, are sent in big endian byte order.

1. I2C Write Register(s)
   A write register operation consists of an I2C write of two address bytes and four data bytes for each register to write. Several registers can be written in the same I2C transaction, the register address will be incremented by one for each four data bytes.

   • Example 1: Writing six bytes will write one register, two address bytes and four data bytes.
   • Example 2: Writing 18 bytes will write four registers, two address bytes and 16 data bytes.
     Example operation, write 0x11223344 to address 0x0025.Description| Data
     ---|---
     I2C Start Condition|
     Slave Address + Write| 0x52 + W
     Address to slave [15:8]| 0x00
     Address to slave [7:0]| 0x25
     Data to slave [31:24]| 0x11
     Data to slave [23:16]| 0x22
     Data to slave [15:8]| 0x33
     Data to slave [7:0]| 0x44
     I2C Stop Condition|

2. I2C Read Register(s)
   A read register operation consists of an I2C write of two address bytes followed by an I2C read of four data bytes for each register to read. Several registers can be read in the same I2C transaction, the register address will be incremented by one for each four data bytes.

   • Example 1: Writing two bytes and reading four bytes will read one register.
   • Example 2: Writing two bytes and reading 16 bytes will read four registers.
     Example operation, read 0x12345678 from address 0x0003. Description| Data
     ---|---
     I2C Start Condition|
     Slave Address + Write| 0x52 + W
     Address to slave [15:8]| 0x00
     Address to slave [7:0]| 0x03
     I2C Stop Condition|
     I2C Start Condition|
     Slave Address + Read| 0x52 + R
     Data from slave [31:24]| 0x12
     Data from slave [23:16]| 0x34
     Data from slave [15:8]| 0x56
     Data from slave [7:0]| 0x78
     I2C Stop Condition|

Register Protocol – Low Power Mode

1. I2C Communication with Low Power Mode
   • Low power example

File Structure

The I2C Presence Detector application consists of the following files.

• acc reg protocol.c A generic protocol handler implementation.
• presence reg protocol.c The specific register protocol setup for the I2C Presence Detector.
• presence reg protocol access.c The register read and write access functions for the I2C Presence Detector.
• i2c application system stm32.c System functions, such as I2C handling, GPIO control and low-power state
• i2c presence detector.c The I2C Presence Detector application.

Embedded Host Example

This is an example implementation of the host read and write register functions using the STM32 SDK.

Register Read/Write functions

Detector setup functions

Registers

1. Register Map**
   Address| Register Name| Type**
   ---|---|---
   0x0000| Version| Read Only
   0x0001| Protocol Status| Read Only
   0x0002| Measure Counter| Read Only
   0x0003| Detector Status| Read Only
   0x0010| Presence Result| Read Only
   0x0011| Presence Distance| Read Only
   0x0012| Intra Presence Score| Read Only
   0x0013| Inter Presence Score| Read Only
   0x0040| Sweeps Per Frame| Read / Write
   0x0041| Inter Frame Presence Timeout| Read / Write
   0x0042| Inter Phase Boost Enabled| Read / Write
   0x0043| Intra Detection Enabled| Read / Write
   0x0044| Inter Detection Enabled| Read / Write
   0x0045| Frame Rate| Read / Write
   0x0046| Intra Detection Threshold| Read / Write
   0x0047| Inter Detection Threshold| Read / Write
   0x0048| Inter Frame Deviation Time Const| Read / Write
   0x0049| Inter Frame Fast Cutoff| Read / Write
   0x004a| Inter Frame Slow Cutoff| Read / Write
   0x004b| Intra Frame Time Const| Read / Write
   0x004c| Intra Output Time Const| Read / Write
   0x004d| Inter Output Time Const| Read / Write
   0x004e| Auto Profile Enabled| Read / Write
   0x004f| Auto Step Length Enabled| Read / Write
   0x0050| Manual Profile| Read / Write
   0x0051| Manual Step Length| Read / Write
   0x0052| Start| Read / Write
   0x0053| End| Read / Write
   0x0054| Reset Filters On Prepare| Read / Write
   0x0055| Hwaas| Read / Write
   0x0080| Detection On Gpio| Read / Write
   0x0100| Command| Write Only

Register Descriptions

1. Version**
   Address| 0x0000
   ---|---
   Access| Read Only
   Register Type| field
   Description| Get the RSS version.
   Bitfield| Pos| Width| Mask**
   ---|---|---|---
   MAJOR| 16| 16| 0xffff0000
   MINOR| 8| 8| 0x0000ff00
   PATCH| 0| 8| 0x000000ff
   • MAJOR – Major version number
   • MINOR – Minor version number
   • PATCH – Patch version number
2. Protocol Status**
   Address| 0x0001
   ---|---
   Access| Read Only
   Register Type| field
   Description| Get protocol error flags.
   Bitfield| Pos| Width| Mask**
   ---|---|---|---
   PROTOCOL STATE ERROR| 0| 1| 0x00000001
   PACKET LENGTH ERROR| 1| 1| 0x00000002
   ADDRESS ERROR| 2| 1| 0x00000004
   WRITE FAILED| 3| 1| 0x00000008
   WRITE TO READ ONLY| 4| 1| 0x00000010
   • PROTOCOL STATE ERROR – Protocol state error
   • PACKET LENGTH ERROR – Packet length error ADDRESS ERROR – Register address error
   • WRITE FAILED – Write register failed
   • WRITE TO READ ONLY – Write to read only register
3. Measure Counter**
   Address| 0x0002
   ---|---
   Access| Read Only
   Register Type| uint
   Description**| Get the measure counter, the number of measurements performed since restart.
4. Detector Status**
   Address| 0x0003
   ---|---
   Access| Read Only
   Register Type| field
   Description| Get detector status flags.
   Bitfield| Pos| Width| Mask**
   ---|---|---|---
   RSS REGISTER OK| 0| 1| 0x00000001
   CONFIG CREATE OK| 1| 1| 0x00000002
   SENSOR CREATE OK| 2| 1| 0x00000004
   SENSOR CALIBRATE OK| 3| 1| 0x00000008
   DETECTOR CREATE OK| 4| 1| 0x00000010
   DETECTOR BUFFER OK| 5| 1| 0x00000020
   SENSOR BUFFER OK| 6| 1| 0x00000040
   CONFIG APPLY OK| 7| 1| 0x00000080
   RSS REGISTER ERROR| 16| 1| 0x00010000
   CONFIG CREATE ERROR| 17| 1| 0x00020000
   SENSOR CREATE ERROR| 18| 1| 0x00040000
   SENSOR CALIBRATE ERROR| 19| 1| 0x00080000
   DETECTOR CREATE ERROR| 20| 1| 0x00100000
   DETECTOR BUFFER ERROR| 21| 1| 0x00200000
   SENSOR BUFFER ERROR| 22| 1| 0x00400000
   CONFIG APPLY ERROR| 23| 1| 0x00800000
   DETECTOR ERROR| 28| 1| 0x10000000
   BUSY| 31| 1| 0x80000000
   • RSS REGISTER OK – RSS register OK
   • CONFIG CREATE OK – Configuration create OK
   • SENSOR CREATE OK – Sensor create OK
   • SENSOR CALIBRATE OK – Sensor calibrate OK
   • DETECTOR CREATE OK – Detector create OK
   • DETECTOR BUFFER OK – Detector get buffer size OK
   • SENSOR BUFFER OK – Memory allocation of sensor buffer OK
   • CONFIG APPLY OK – Detector configuration apply OK
   • RSS REGISTER ERROR – RSS register error
   • CONFIG CREATE ERROR – Configuration create error
   • SENSOR CREATE ERROR – Sensor create error
   • SENSOR CALIBRATE ERROR – Sensor calibrate error
   • DETECTOR CREATE ERROR – Detector create error
   • DETECTOR BUFFER ERROR – Detector get buffer size error
   • SENSOR BUFFER ERROR – Memory allocation of sensor buffer error
   • CONFIG APPLY ERROR – Detector configuration apply error
   • DETECTOR ERROR – Detector error occured, restart necessary
   • BUSY – Detector busy
5. Presence Result**
   Address| 0x0010
   ---|---
   Access| Read Only
   Register Type| field
   Description| The result from the presence detector.
   Bitfield| Pos| Width| Mask**
   ---|---|---|---
   PRESENCE DETECTED| 0| 1| 0x00000001
   PRESENCE DETECTED STICKY| 1| 1| 0x00000002
   DETECTOR ERROR| 15| 1| 0x00008000
   TEMPERATURE| 16| 16| 0xffff0000
   • PRESENCE DETECTED – Presence detected
   • PRESENCE DETECTED STICKY – Presence detected, sticky bit with clear on read
   • DETECTOR ERROR – The presence detector failed
   • TEMPERATURE – Temperature in sensor during measurement (in degree Celsius). Note that it has poor absolute accuracy and should only be used for relative temperature measurements.
6. Presence Distance**
   Address| 0x0011
   ---|---
   Access| Read Only
   Register Type| uint
   Unit| mm
   Description**| The distance, in millimeters, for the detected presence
7. Intra Presence Score**
   Address| 0x0012
   ---|---
   Access| Read Only
   Register Type| uint
   Description**| A measure of the amount of fast motion detected.
8. Inter Presence Score**
   Address| 0x0013
   ---|---
   Access| Read Only
   Register Type| uint
   Description**| A measure of the amount of slow motion detected.
9. Sweeps Per Frame**
   Address| 0x0040
   ---|---
   Access| Read / Write
   Register Type| uint
   Description| The number of sweeps that will be captured in each frame (measurement).
   Default Value**| 16
10. Inter Frame Presence Timeout**
    Address| 0x0041
    ---|---
    Access| Read / Write
    Register Type| uint
    Description| Number of seconds the inter-frame presence score needs to decrease before exponential scaling starts for faster decline. Should be between 0 and 30 where 0 means no timeout.
    Default Value**| 3
11. Inter Phase Boost Enabled**
    Address| 0x0042
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Enable to increase detection of slow motions by utilizing the phase information in the Sparse IQ data.
    Default Value**| False
12. Intra Detection Enabled**
    Address| 0x0043
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Enable to detect faster movements inside frames.
    Default Value**| True
13. Inter Detection Enabled**
    Address| 0x0044
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Enable to detect slower movements between frames.
    Default Value**| True
14. Frame Rate**
    Address| 0x0045
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| mHz
    Description| The presence detector frame rate. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 12000
15. Intra Detection Threshold**
    Address| 0x0046
    ---|---
    Access| Read / Write
    Register Type| uint
    Description| The threshold for detecting faster movements inside frames. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 1300
16. Inter Detection Threshold**
    Address| 0x0047
    ---|---
    Access| Read / Write
    Register Type| uint
    Description| This is the threshold for detecting slower movements between frames. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 1000
17. Inter Frame Deviation Time Const**
    Address| 0x0048
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| ms
    Description| The time constant of the low pass filter for the inter- frame deviation between fast and slow. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 500
18. Inter Frame Fast Cutoff**
    Address| 0x0049
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| mHz
    Description| The cutoff frequency of the low pass filter for the fast filtered absolute sweep mean. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 6000
19. Inter Frame Slow Cutoff**
    Address| 0x004a
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| mHz
    Description| The cutoff frequency of the low pass filter for the slow filtered absolute sweep mean. Note: This value is a factor 1000 larger than the RSS value.
    ---|---
    Default Value**| 200
20. Intra Frame Time Const**
    Address| 0x004b
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| ms
    Description| The time constant for the depthwise filtering in the intra- frame part. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 150
21. Intra Output Time Const**
    Address| 0x004c
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| ms
    Description| The time constant for the output in the intra-frame part. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 300
22. Inter Output Time Const**
    Address| 0x004d
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| ms
    Description| The time constant for the output in the inter-frame part. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 2000
23. Auto Profile Enabled**
    Address| 0x004e
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Enable/Disable automatic selection of profile based on start point of measurement.
    Default Value**| True
24. Auto Step Length Enabled**
    Address| 0x004f
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Enable/Disable automatic selection of step length based on the profile.
    Default Value**| True
25. Manual Profile**
    Address| 0x0050
    ---|---
    Access| Read / Write
    Register Type| enum
    ---|---
    Description| The profile to use. The profile will only be used if profile auto selection was disabled.
    Default Value| PROFILE4
    Enum| Value**
    ---|---
    PROFILE1| 1
    PROFILE2| 2
    PROFILE3| 3
    PROFILE4| 4
    PROFILE5| 5
    • PROFILE1 – Profile 1
    • PROFILE2 – Profile 2
    • PROFILE3 – Profile 3
    • PROFILE4 – Profile 4
    • PROFILE5 – Profile 5
26. Manual Step Length**
    Address| 0x0051
    ---|---
    Access| Read / Write
    Register Type| uint
    Description| The number of steps between each data point. The manual step length will only be used if step length auto selection was disabled.
    Default Value**| 72
27. Start**
    Address| 0x0052
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| mm
    Description| The start point of measurement interval in millimeters. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 300
28. End**
    Address| 0x0053
    ---|---
    Access| Read / Write
    Register Type| uint
    Unit| mm
    Description| The end point of measurement interval in millimeters. Note: This value is a factor 1000 larger than the RSS value.
    Default Value**| 2500
29. Reset Filters On Prepare**
    Address| 0x0054
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Enable/Disable reset of the presence filters during start/restart.
    Default Value**| True
30. Hwaas**
    Address| 0x0055
    ---|---
    Access| Read / Write
    Register Type| uint
    Description| The hardware accelerated average samples (HWAAS).
    Default Value**| 32
31. Detection On Gpio**
    Address| 0x0080
    ---|---
    Access| Read / Write
    Register Type| bool
    Description| Output presence detection on generic gpio
    Default Value**| False
32. Command**
    Address| 0x0100
    ---|---
    Access| Write Only
    Register Type| enum
    Description| Execute command.
    Enum| Value**
    ---|---
    APPLY CONFIGURATION| 1
    START DETECTOR| 2
    STOP DETECTOR| 3
    ENABLE UART LOGS| 32
    DISABLE UART LOGS| 33
    LOG CONFIGURATION| 34
    RESET MODULE| 1381192737
    • APPLY CONFIGURATION – Apply the configuration
    • START DETECTOR – Start the presence detector
    • STOP DETECTOR – Stop the presence detector
    • ENABLE UART LOGS – DEBUG: Enable UART Logs
    • DISABLE UART LOGS – DEBUG: Disable UART Logs
    • LOG CONFIGURATION – DEBUG: Print detector configuration to
    • UART RESET MODULE – Reset module, needed to make a new configuration

Disclaimer

The information herein is believed to be correct as of the date issued. Acconeer AB (“Acconeer”) will not be responsible for damages of any nature resulting from the use or reliance upon the information contained herein. Acconeer makes no warranties, expressed or implied, of merchantability or fitness for a particular purpose or course of performance or usage of trade. Therefore, it is the user’s responsibility to thoroughly test the product in their particular application to determine its performance, efficacy and safety. Users should obtain the latest relevant information before placing orders. Unless Acconeer has explicitly designated an individual Acconeer product as meeting the requirement of a particular industry standard, Acconeer is not responsible for any failure to meet such industry standard requirements. Unless explicitly stated herein this document Acconeer has not performed any regulatory conformity test. It is the user’s responsibility to assure that necessary regulatory conditions are met and approvals have been obtained when using the product. Regardless of whether the product has passed any conformity test, this document does not constitute any regulatory approval of the user’s product or application using Acconeer’s product. Nothing contained herein is to be considered as permission or a recommendation to infringe any patent or any other intellectual property right. No license, express or implied, to any intellectual property right is granted by Acconeer herein. Acconeer reserves the right to at any time correct, change, amend, enhance, modify, and improve this document and/or Acconeer products without notice.
This document supersedes and replaces all information supplied prior to the publication hereof.

© 2023 by Acconeer AB – All rights reserved

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