STMicroelectronics STEVAL-MKI121V1 Discovery-M1 Evaluation board User manual

UM1744

User manual

STEVAL- MKI121V1 communication protocol

Introduction

The scope of this user manual is to present the communication protocol used between the

STEVAL-MKI121V1 product evaluation board (Discovery-M1) and the iNEMO SDK

(Software Development Kit). This communication protocol runs upon a physical communication channel based on USB virtual COM, which represents the physical channel used in the communication between the STEVAL-MKI121V1 and the PC.

The first chapter explains the general frame format and main rules used in the protocol.

The second chapter explains all the frames used in the actual release of the embedded firmware and Software Development Kit (SDK).

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Contents

Contents

1

2

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General frame format and protocol rules . . . . . . . . . . . . . . . . . . . . . . . . 4

1.1

Frame format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.1.1

1.1.2

1.1.3

Frame control field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Length field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Message ID field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1.2

Protocol rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

STEVAL-MKI121V1 frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.1

STEVAL-MKI121V1 frame types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2

Communication control frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

2.2.1

2.2.2

2.2.3

2.2.4

2.2.5

2.2.6

iNEMO_Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 iNEMO_Disconnect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 iNEMO_Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

iNEMO_Enter_DFU_Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

iNEMO_Trace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 iNEMO_Led_Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2.3

Board information frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

2.3.1

2.3.2

2.3.3

2.3.4

2.3.5

2.3.6

2.3.7

iNEMO_Get_MCU_ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 iNEMO_Get_FW_Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

iNEMO_Get_HW_Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 iNEMO_Identify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 iNEMO_Get_AHRS_Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

iNEMO_Get_Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 iNEMO_Get_Available_Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.4

Sensor setting frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.4.1

2.4.2

2.4.3

2.4.4

2.4.5

2.4.6

2.4.7

2.4.8

2.4.9

iNEMO_Set_Sensor_Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

iNEMO_Get_Sensor_Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 iNEMO_Restore_Default_Parameter . . . . . . . . . . . . . . . . . . . . . . . . . . 18

iNEMO_Save_to_Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

iNEMO_Load_from_Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Accelerometer "Sensor_Parameter" field . . . . . . . . . . . . . . . . . . . . . . . 20

Accelerometer Output_Data_rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Accelerometer full scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Accelerometer high-pass filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

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2.4.10

Accelerometer offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.4.11

Accelerometer scale factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.4.12

Accelerometer sensor name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

2.4.13

Magnetometer "Sensor_Parameter" field . . . . . . . . . . . . . . . . . . . . . . . 22

2.4.14

Magnetometer Output_Data_rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.4.15

Magnetometer full scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.4.16

Magnetometer operating mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.4.17

Magnetometer offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.4.18

Magnetometer scale factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

2.4.19

Magnetometer sensor name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.4.20

Calibration sensor frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.4.21

iNEMO_Start_HIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.4.22

iNEMO_Abort_HIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2.4.23

Gyroscope "Sensor_Parameter" field . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.4.24

Gyroscope output data rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.4.25

Gyroscope full scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.4.26

Gyroscope offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.4.27

Gyroscope scale factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.4.28

Gyroscope sensor name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.4.29

Pressure "Sensor_Parameter" field . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.4.30

Pressure sensor output data rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.4.31

Pressure sensor offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.4.32

Pressure scale factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.4.33

Pressure sensor name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.4.34

Temperature "Sensor_Parameter" field . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.4.35

Temperature sensor offset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.4.36

Temperature sensor scale factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.4.37

Temperature sensor name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.5

Acquisition sensor data frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

2.5.1

2.5.2

2.5.3

2.5.4

2.5.5

iNEMO_Set_Output_Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

iNEMO_Get_Output_Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 iNEMO_Start_Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

iNEMO_Stop_Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 iNEMO_Get_Acquired_Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

2.6

Error code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

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General frame format and protocol rules

1 General frame format and protocol rules

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This paragraph explains the format of the frame used in the STEVAL-MKI121V1 communication protocol. Because, the STEVAL-MKI121V1 exchanges data and commands with the PC GUI through a physical communication channel based on a USB Virtual COM, each frame, described below, represents the payload of a USB frame.

Figure 1. STEVAL-MKI121V1 communication architecture

The frames are described as a sequence of fields in a specific order. All frame formats are depicted in the order in which they are passed to the USB driver, from left to right. Bits within each field are numbered from k-1 (leftmost and most significant) to 0 (rightmost and least significant), where the length of the field is k bits.

The frame format is composed of a header and an optional payload. The general frame

shall be formatted as illustrated in

Figure 2

. The header is composed of three mandatory

(M) fields, each of which is 1 byte in length, while the payload is an optional field whose maximum length is 61 bytes. See LF/MF field in the following section to overcome this limit.

Figure 2. General frame format

1.1.1 Frame control field

The frame control field is 1 byte in length and contains information defining the frame type

and other control flags. The frame control field shall be formatted as illustrated in

Figure 3

.

Figure 3. Frame control field

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UM1744 General frame format and protocol rules

The frame type subfield is 2 bits in length and shall be set to one of the values listed in

Table 1

.

Table 1. Frame type list

Value

00

01

10

11

Frame type

CONTROL

DATA

ACK

NACK

The Ack subfield is 1 bit in length and specifies whether an acknowledgment is required from the recipient on receipt of a DATA or CONTROL frame. If this subfield is set to one, the recipient shall send an acknowledgment frame only if, upon reception, the frame passes all the needed levels of filtering. If this subfield is set to zero, the recipient device shall not send an acknowledgment frame. It is possible to embed a payload in an acknowledgment frame

(piggybacking) to send useful information to the transmitter and avoiding further transactions. When the Ack field is set to one and upon reception the frame doesn't pass the needed level of filtering, the recipient shall send a not-acknowledgment frame (NACK), whose payload is an error code (e.g. unsupported command, value out of range,…). In the

ACK and/or NACK frames the Ack field shall be set to zero and ignored on reception.

The LF/MF (Last Fragment / More Fragment) subfield is 1 bit in length and it is used for fragmentation and reassembling. This field is set to zero to indicate a single frame or the last frame of a multiple-frame transaction. This field is set to 1 to indicate that other frames will follow all those belonging to the same transaction. In the ACK and NACK frames (with or without payload) fragmentation is not supported and this subfield shall be set to zero in transmission of ACK and NACK frames and ignored on reception.

The frame version subfield is 2 bits in length and shall be set to the non-reserved for future

use (RFU) value listed in

Table 2

.

Value

00

01

10

11

Table 2. Frame version list

Frame version

Version 1

RFU

The QoS (Quality of Service) subfield is 2 bits in length and shall be set to one of the values listed in

Table 3

. This subfield allows the application to exchange and process data and

control frames with different priorities.

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Value

00

01

10

11

Table 3. QoS list

Frame version

Normal Priority

Medium Priority

High Priority

RFU

The length field is 1 byte in length and contains the number of bytes that follow the length field. Admitted values are in the range 1 ÷ 62.

The message ID is 1 byte in length and contains an identifier of the user application

messages. See

Section 2.2

and the following sections for further details.

There are two types of transactions: acknowledgment or non-acknowledgment of the DATA or CONTROL frame.

A DATA or CONTROL frame with the Ack subfield of its frame control field set to zero shall not be acknowledged by its intended recipient. The originating device (PC or Discovery-M1 board) shall assume that the transmission of the frame was successful. The message sequence chart in

Figure 4

shows the scenario for transmitting a single DATA or CONTROL

frame from an originator to a recipient without requiring an acknowledgment.

Figure 4. Data or control frame transmission without an acknowledgment

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A DATA or CONTROL frame transmitted with the Ack subfield of its frame control field set to one shall be acknowledged by the recipient. If the intended recipient correctly receives the frame, it shall generate and send an ACK frame containing the same message ID from the

DATA or CONTROL frame that is being acknowledged. It is possible also to include a payload in the ACK frame to transfer useful data from the recipient to the originator. The

message sequence chart in

Figure 5

shows the scenario for transmitting a single DATA or

CONTROL frame from an originator to a recipient with an acknowledgment.

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Figure 5. Data or control frame transmission with an acknowledgment

If the frame received does not conform to all the required filtering rules, the recipient shall generate and send a NACK frame containing the same message ID from the DATA or

CONTROL frame that is being acknowledged and containing the error code. The message

sequence chart in

Figure 6

shows the scenario for transmitting a single "bad" DATA or

CONTROL frame from an originator to a recipient with a not-acknowledgment.

Figure 6. "Bad" data or control frame transmission with not-acknowledgment

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STEVAL-MKI121V1 frames UM1744

2.1 STEVAL-MKI121V1 frame types

The frames used in the STEVAL-MKI121V1 are classified in five types:

1.

Communication control frames

2. Board information frames

3. Sensor setting frames

4. Acquisition sensor data frames

2.2 Communication control frames

Communication control frames are frames originated by the software PC (SDK or GUI) and used to send specific commands to the Discovery-M1 board. All the communication control frames are listed in

Table 4

.

Commands

iNEMO _Connect iNEMO _Connect_Response iNEMO _Disconnect iNEMO_Disconnect_Response

CONTROL

ACK

NACK

CONTROL

ACK

NACK iNEMO_Reset_Board iNEMO_Reset_Board_Response

CONTROL

ACK

NACK iNEMO_Enter_DFU_Mode iNEMO_Enter_DFU_Mode_

Response

CONTROL

ACK

NACK iNEMO_Trace iNEMO_Trace_Response

CONTROL

ACK

NACK iNEMO_Trace_Data iNEMO_Led_Control iNEMO_Led_Control_Response

Table 4. Communication control frames

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

Payload

DATA

CONTROL

ACK

NACK

Y

N

N

Y

N

N

Y

N

N

Y

N

N

Y

N

N

N

Y

N

N

0x03

0x03

0x03

0x07

0x07

0x07

0x00

0x00

0x00

0x01

0x01

0x01

0x02

0x02

0x02

0x07

0x08

0x08

0x08

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

M

N

Originator

0

0

1

0

0

1

0

0

1

0

0

1

0

0

1

Error Code

Error Code

Error Code

Error Code

PC

Discovery-M1

PC

Discovery-M1

PC

Discovery-M1

PC

Discovery-M1

PC

Variable

1

Error Code

Discovery-M1

String for debug purpose

0x00 OFF

0x01 ON

PC

0

1 Error Code

Discovery-M1

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2.2.1 iNEMO_Connect

The iNEMO_Connect command shall be the first command sent from the GUI or SDK to the

Discovery-M1 board. Any other command sent before the iNEMO_Connect will not be processed by Discovery-M1. It works like a "ping" and opens the communication between the GUI or SDK and the Discovery-M1 board at the application level.

Figure 7

shows the frames involved in the iNEMO_Connect transaction.

Figure 7. iNEMO_Connect frames

2.2.2 iNEMO_Disconnect

The iNEMO_Disconnect command closes the communication between the PC and the

Discovery-M1 board.

Figure 8

shows the frames involved in the iNEMO_Disconnect transaction.

Figure 8. iNEMO_Disconnect frames

The GUI (or SDK), after receiving the ACK frame, shall close the USB Virtual Com. To reopen the communication only the iNEMO_Connect command shall be used.

2.2.3 iNEMO_Reset

The iNEMO_Reset command implies a software reset of the Discovery-M1 board. After receiving the iNEMO_Reset command, the Discovery-M1 board replies with the ACK frame; then waits for 5 seconds before disconnecting the USB cable in software mode and invokes a software reset. The GUI (or SDK), after receiving the ACK frame, shall close the USB

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STEVAL-MKI121V1 frames UM1744

Virtual Com. To re-open the communication only the iNEMO_Connect command shall be used.

Figure 9

shows the frames involved in the iNEMO_Reset transaction.

Figure 9. iNEMO_Reset frames

2.2.4 iNEMO_Enter_DFU_Mode

The iNEMO_Enter_DFU_Mode command allows the Discovery-M1 board to enter in DFU mode in software mode. After receiving the iNEMO_Enter_DFU_Mode command, the

Discovery-M1 board replies with an ACK frame. Then it will set the Option Byte Data0 (at address 0x1FFFF804) to one, will disconnect the USB cable in software mode, and it will invoke a software reset. After reset, the Discovery-M1 will enter in DFU mode. After entering in DFU mode in software, the Discovery-M1 will change the Option Byte Data0 to zero. The user can leave the DFU mode in two ways: by unplugging and plugging in the USB cable

(hardware mode), or by using the Leave_DFU_Mode command available in the DfuSe

Demo PC application or in the GUI or SDK. The GUI (or SDK) shall close the USB Virtual

Com after receiving the ACK frame.

Figure 10

shows the frames involved in the iNEMO_Enter_DFU_Mode transaction

Figure 10. iNEMO_Enter_DFU_Mode frames

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2.2.5 iNEMO_Trace

The iNEMO_Trace command allows the user to enable or disable "trace data". Trace data are used for debugging purposes and they will be string displayed in a debug window. The frames are asynchronous and shall have medium priority (QoS sub-field of frame control field).

Figure 11

shows the frames involved in the iNEMO_Trace transaction

Figure 11. iNEMO_Trace frames

2.2.6 iNEMO_Led_Control

The iNEMO_Led_Control command allows turning on and off the LED available on the iNEMO board.

Figure 12

shows the frames involved in the iNEMO_Led_Control transaction.

Figure 12. iNEMO_Led_Control frames

Board information frames are frames originated by the software PC (SDK or GUI) and used to retrieve information about firmware and hardware features of the Discovery-M1 board. All the board information frames are listed in

Table 5

.

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Commands

iNEMO_Get_Device_Mode iNEMO_Get_Device_Mode_

Response iNEMO_Get_MCU_ID iNEMO_Get_MCU_ID_Response iNEMO_Get_FW_Version iNEMO_Get_FW_Version_

Response iNEMO_Get_HW_Version iNEMO_Get_HW_Version_

Response iNEMO_Identify iNEMO_Identify_Response iNEMO_Get_AHRS_Library iNEMO_Get_AHRS_Library_

Response iNEMO_Get_Libraries iNEMO_Get_Libraries_Response

Table 5. Board information frames

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

CONTROL Y 0x10 N

ACK

NACK

CONTROL

ACK

NACK

CONTROL

ACK

NACK

CONTROL

ACK

NACK

CONTROL

ACK

NACK

CONTROL

ACK

NACK

CONTROL

ACK

NACK iNEMO_Get_Available_Sensors CONTROL

N

N

Y

N

N

Y

N

N

Y

N

N

Y

N

N

Y

N

N

Y

N

N

Y

0x10

0x10

0x12

0x12

0x12

0x13

0x13

0x13

0x14

0x14

0x14

0x15

0x15

0x15

0x17

0x17

0x17

0x18

0x18

0x18

0x19

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

N

Payload Originator

0

1

1

0

12

1

0

Variable

1

0

Variable

1

0

12

1

0

Variable

1

0

0

1

0

PC

0x00

Sensor

Mode

0x01

Master

Mode

Error Code

Discovery-M1

PC

Unique

Device ID

Discovery-M1

Error Code

PC

String

Firmware

Version

Discovery-M1

Error Code

Date, Time PC

String

Hardware

Version

Discovery-M1

Error Code

PC

Unique

Device ID

Discovery-M1

Error Code

PC

AHRS enable/dis able string Discovery-M1

Error Code

PC

List of supported libraries

Discovery-M1

Error Code

PC

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Commands

Table 5. Board information frames (continued)

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

Payload Originator

iNEMO_Get_Available_Sensors_

Response

ACK

NACK

N

N

0x19

0x19

N

N

1

1

List of available sensors

Discovery-M1

Error Code

2.3.1 iNEMO_Get_MCU_ID

The iNEMO_Get_MCU_ID command allows retrieving from the Discovery-M1 board the

96-bit unique device identifier of the STM32F103 microcontroller.

Figure 13

shows the

frames involved in the iNEMO_Get_MCU_ID transaction.

Figure 13. iNEMO_Get_MCU_ID frames

2.3.2 iNEMO_Get_FW_Version

The iNEMO_Get_FW_Version command allows retrieving the board firmware version.

Figure 14

shows the frames involved in the iNEMO_Get_FW_Version transaction

Figure 14. : iNEMO_Get_FW_Version frames

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STEVAL-MKI121V1 frames UM1744

2.3.3 iNEMO_Get_HW_Version

The iNEMO_Get_HW_Version command allows retrieving the board hardware version.

Figure 15

shows the frames involved in the iNEMO_Get_HW_Version transaction.

Figure 15. iNEMO_Get_HW_Version frames

2.3.4 iNEMO_Identify

The iNEMO_Identify command can be used to identify a Discovery-M1 board. Upon reception of the iNEMO_Identify command the Discovery-M1 board replies with an ACK containing the MCU Unique Device ID. Then the LED available on the board will blink 3

times.

Figure 16

shows the frames involved in the iNEMO_Identify transaction

Figure 16. iNEMO_Identify frames

2.3.5 iNEMO_Get_AHRS_Library

The iNEMO_Get_AHRS_Library command allows knowing the version of the Discovery-M1 firmware Attitude Heading Reference System (AHRS) algorithm. The returned value is in string format.

Figure 17

shows the frames involved in the iNEMO_Get_AHRS_Library

transaction.

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Figure 17. iNEMO_Get_AHRS_Library frames

2.3.6 iNEMO_Get_Libraries

The iNEMO_Get_Libraries command allows knowing which specific libraries are supported by the Discovery-M1 firmware.

Figure 18

shows the frames involved in the

iNEMO_Get_Libraries transaction.

Figure 18. iNEMO_Get_Libraries frames

2.3.7 iNEMO_Get_Available_Sensors

The iNEMO_Get_Available_Sensors command allows knowing which specific sensors are

supported by the Discovery-M1 firmware.

Figure 19

shows the frames involved in the

iNEMO_Get_Available_Sensors transaction

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Figure 19. iNEMO_Get_Available_Sensors frames

UM1744

2.4 Sensor setting frames

Sensor setting frames are frames originated by the software PC (SDK or GUI) and used to set sensor parameters or to retrieve information about them. All the sensor setting frames are listed in

Table 6

.

Commands

Table 6. Sensor setting frames

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

Payload Originator

Commands iNEMO_Set_Sensor_Parameter CONTROL iNEMO_Set_Sensor_Parameter_

Response iNEMO_Get_Sensor_Parameter_

Response

Frame

Type

ACK

NACK iNEMO_Get_Sensor_Parameter CONTROL

ACK

NACK

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

Y

N

N

Y

N

N

0x20

0x20

0x20

0x21

0x21

0x21

Payload Originator

N

N

N variable

Sensor_

Type,

Sensor_

Parameter,

Parameter_

Value

0

1 Error Code

PC

Discovery-M1

N

N variable

N

2

1

Sensor_

Type,

Sensor_

Parameter,

PC

Sensor_

Type,

Sensor_

Parameter,

Parameter_

Value

Discovery-M1

Error Code

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Commands

iNEMO_Restore_Default_

Parameter iNEMO_Restore_Default_

Parameter_Response iNEMO_Save_to_Flash iNEMO_Save_to_Flash_

Response iNEMO_Load_from_Flash iNEMO_Load_from_Flash_

Response

Table 6. Sensor setting frames (continued)

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

Payload

CONTROL

ACK

NACK

CONTROL

ACK

NACK

CONTROL

ACK

NACK

Y

N

N

N

N

Y

N

Y

N

0x22

0x22

0x22

0x23

0x23

0x23

0x24

0x24

0x24

Originator

N

N

N

N

N

N 2

N variable

N

N

1

0

Sensor_

Type,

Sensor_

Parameter

Error Code

PC

Sensor_

Type,

Sensor_

Parameter,

Parameter_

Value

Discovery-M1

PC

0

1 Error Code

Discovery-M1

PC

1 Error Code

Discovery-M1

2.4.1 iNEMO_Set_Sensor_Parameter

The iNEMO_Set_Sensor_Parameter command allows setting a specific sensor parameter.

Figure 20

shows the frames involved in the iNEMO_Set_Sensor_Parameter transaction.

Figure 20. iNEMO_Set_Sensor_Parameter frames

Table 7

describes the "Sensor_Type" field.

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2.4.2 iNEMO_Get_Sensor_Parameter

The iNEMO_Get_Sensor_Parameter command allows retrieving from the Discovery-M1 a specific sensor parameter.

Figure 21

shows the frames involved in the iNEMO_Get_Sensor_Parameter transaction.

Figure 21. iNEMO_Get_Sensor_Parameter frames

Table 7

describes the "Sensor_Type" field.

2.4.3 iNEMO_Restore_Default_Parameter

The iNEMO_Restore_Default_Parameter command allows restoring a default, specific sensor parameter.

Figure 22

shows the frames involved in the iNEMO_Restore_Default_Parameter transaction.

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Figure 22. iNEMO_Restore_Default_Parameter frames

Table 7

describes the "Sensor_Type" list.

Sensor_Type Field

0x00

0x01

0x02

0x03

0x04

0x05

0x06 – 0xFF

Table 7. Sensor_Type list

Sensor

3-axis accelerometer

3-axis magnetometer

3-axis gyroscope

-

Pressure

Temperature

Reserved for Future Use

2.4.4 iNEMO_Save_to_Flash

The iNEMO_Save_to_Flash command allows storing the settings of the sensor parameters in Discovery-M1 flash.

Figure 23

shows the frames involved in the iNEMO_Save_to_Flash

transaction.

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Figure 23. iNEMO_Save_to_Flash frames

UM1744

2.4.5 iNEMO_Load_from_Flash

The iNEMO_Load_from_Flash command allows loading from Discovery-M1 flash the sensors parameters stored in it.

Figure 24

shows the frames involved in the iNEMO_Load_from_Flash transaction.

Figure 24. iNEMO_Load_from_Flash frames

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Table 8

describes the parameters of the accelerometer sensor and the values of the

"Sensor_Parameter" field.

Table 8. Accelerometer Sensor_Parameter list

Sensor_Parameter field Sensor

0x00

0x01

0x02

0x03

0x04

0x05

0x06

Output data rate

Full scale

Acc_HPF

Offset_X

Offset_Y

Offset_Z

Scale factor X

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Table 8. Accelerometer Sensor_Parameter list (continued)

Sensor_Parameter field Sensor

0x07

0x08

0xFF

0x09 – 0xFE

Scale factor Y

Scale factor Z

Sensor name (read only)

Reserved for Future Use

The "Parameter_Value" field for the output data rate setting is 1 byte in length.

Table 9

describes the supported output data rate for the accelerometer.

Table 9. Accelerometer output data rate field

Parameter_Value field for accelerometer ODR Output data rate (Hz)

0x00

0x01

0x02

0x03

0x04

0x05

0x06

0x07– 0xFF

1

10

25

50

100

200

400

RFU

The "Parameter_Value" field for the full-scale setting is 1 byte in length.

Table 10

describes the supported full scale for the accelerometer.

Table 10. Accelerometer full scale field

Parameter_Value field for accelerometer FS Full scale (g)

0x00

0x01

0x02

0x03

0x04 – 0xFF

±2g

±4g

±8g

±16g

RFU

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The "Parameter_Value" field for the high-pass filter setting is 2 bytes in length as described in

Figure 25

.

Table 11

describes the possible cutoff frequencies.

Figure 25. "Parameter_Value" fields for accelerometer HPF setting

HP1 HP0

1

1

0

0

0

1

0

1

Table 11. Accelerometer high-pass filter setting f t

[HZ]

Data rate =

1 Hz f t

[HZ]

Data rate =

10 Hz f t

[HZ]

Data rate =

25 Hz f t

[HZ]

Data rate =

50 Hz f t

[HZ]

Data rate =

100 Hz f t

[HZ]

Data rate =

200 Hz f t

[HZ]

Data rate =

400 Hz

0.02

0.01

0.005

0.0026

0.2

0.1

0.05

0.026

0.052

0.26

0.13

0.065

1.04

0.52

0.26

0.13

2.08

1.04

0.52

0.26

4.16

2.08

1.04

0.52

8.33

4.16

2.08

1.04

For further details please refer to the LSM303DLHC datasheet .

The "Parameter_Value" field for the offset (X-, Y- or Z-axis) setting is 2 bytes in length and expressed in milli-g (thousandth of gravitational force) as signed short (16-bit), with the most significant byte first.

2.4.11 Accelerometer scale factor

The "Parameter_Value" field for the scale factor (X-, Y- or Z-axis) setting is 2 bytes in length

(abstract number not mg) as signed short (16-bit) multiplied x1000 and with the most significant byte first. For example, if in the setting view scale factor x is 1.230, it will be multiplied x1000 and sent as 1230 (signed short 16-bit) in this case.

2.4.12 Accelerometer sensor name

The "Parameter_Value" of the sensor name is a read-only field and it returns the name of accelerometer (LSM303DLHC) from Discovery-M1.

Table 12

describes the parameters of the magnetometer sensor and the values of the

"Sensor_Parameter" field.

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Table 12. Accelerometer Sensor_Parameter list

Sensor_Parameter field Parameter

0x00

0x01

0x02

0x03

0x04

0x05

0x06

0x07

0x08

0xFF

0x09 – 0xFE

Output data rate

Full scale

Operating mode

Offset_X

Offset_Y

Offset_Z

Scale factor X

Scale factor Y

Scale factor Z

Sensor name (read only)

RFU

The "Parameter_Value" field for the output data rate setting is 1 byte in length.

Table 13

describes the output data rate supported for the magnetometer.

Table 13. Magnetometer output data rate field

Parameter_Value field for magnetometer ODR Output data rate (Hz)

0x00

0x01

0x02

0x03

0x04

0x05

0x06

0x07

0x08 – 0xFF

0.75

1.5

3

7.5

15

30

75

220

RFU

The "Parameter_Value" field for the full-scale setting is 1 byte in length.

Table 14

describes the full scale supported for the magnetometer.

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Table 14. Magnetometer full-scale field

Parameter_Value field for magnetometer FS Full scale (gauss)

0x01

0x02

0x03

0x04

0x05

0x06

0x07

0x00, 0x08 – 0xFF

±1.3

±1.9

±2.5

±4.0

±4.7

±5.6

±8.1

Forbidden-RFU

UM1744

The "Parameter_Value" field for the operating mode setting is 1 byte in length as described in

Figure 26

.

Table 15

describes the possible magnetometer operating modes.

Figure 26. "Parameter_Value" fields for magnetometer operating mode setting

Mode1

Table 15. Magnetometer operating mode setting

Mode0

Magnetic sensor operating mode

0

0

1

1

0

1

0

1

Normal

Positive bias

Negative bias

Forbidden

For further details please refer to the LSM303DLHC datasheet.

The "Parameter_Value" field for the offset (X-, Y- or Z-axis) setting is 2 bytes in length and expressed in milli-gauss (thousandth of gauss) as signed short (16-bit), with the most significant byte first.

2.4.18 Magnetometer scale factor

The "Parameter_Value" field for the scale factor (X-, Y- or Z-axis) setting is 2 bytes in length

(abstract number not mgauss) as signed short (16-bit) multiplied x1000.

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2.4.19 Magnetometer sensor name

The "Parameter_Value" of sensor name is a read-only field and it returns the name of magnetometer (LSM303DLHC) from Discovery-M1.

2.4.20 Calibration sensor frames

Calibration sensor frames are frames originated by the software PC (SDK or GUI) used to calibrate sensors. The calibration sensor frames implemented in this version of the protocol are related to the magnetometer hard-iron calibration (HIC) as described below.

2.4.21 iNEMO_Start_HIC

The iNEMO_Start_HIC command is used to start the magnetic sensor HIC procedure.

Table 27

shows the frames involved in the iNEMO_Start_HIC transaction.

Figure 27. iNEMO_Start_HIC frames

2.4.22 iNEMO_Abort_HIC

The iNEMO_Abort_HIC command is used to abort the magnetic sensor HIC procedure.

Table 28

shows the frames involved in the iNEMO_Abort_HIC transaction.

Figure 28. iNEMO_Abort_HIC frames

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Table 16

describes the parameters of the gyroscope sensor and the values of the

"Sensor_Parameter" field.

Table 16. Gyroscope Sensor_Parameter list

Sensor_Parameter field Parameter

0x00

0x01

0x02

0x03

0x04

0x05

0x06

0x07

0x08

0xFF

0x09 – 0xFE

Output data rate – LPF cutoff

Full scale

Gyro_HPF

Offset X

Offset Y

Offset Z

Scale factor X

Scale factor Y

Scale factor Z

Sensor name (read only)

RFU

2.4.24 Gyroscope output data rate

The "Parameter_Value" field for the output data rate setting is 1 byte in length.

Table 17

describes the output data rate supported for the gyroscope.

Table 17. Gyroscope output data rate

Parameter_Value field for gyroscope ODR

Output data rate (Hz) LP filter cutoff (Hz)

0x07

0x08

0x09

0x0A

0x0B

0x00

0x01

0x02

0x03

0x04

0x05

0x06

95

190

380

70

20

25

50

110

12.5

25

25

25

12.5

25

50

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Table 17. Gyroscope output data rate (continued)

Parameter_Value field for gyroscope ODR

Output data rate (Hz) LP filter cutoff (Hz)

0x0C

0x0D

0x0E

0x0F

760

30

35

50

110

2.4.25 Gyroscope full scale

The "Parameter_Value" field for the full scale setting is 1 byte in length.

Table 18

describes the full scale supported for the gyroscope.

Table 18. Gyroscope Full Scale field

Parameter_Value field for gyroscope FS Full scale (dps)

0x00

0x01

0x02

0x03 – 0xFF

±250 dps

±500 dps

±2000 dps

Forbidden - RFU

The "Parameter_Value" field for the Offset (X-,Y- and Z-axis) setting is 2 bytes in length and expressed in dps (degrees per second) as signed short (16-bit) with the most significant byte first.

The "Parameter_Value" field for the scale factor (X-, Y- and Z-axis) setting is 2 bytes in length (abstract number not dps) as signed short (16-bit) multiplied x1000.

2.4.28 Gyroscope sensor name

The "Parameter_Value" of the sensor name is a read-only field and it returns the gyroscope part number (L3GD20) present on the Discovery-M1.

Table 19

describes the parameters of the pressure sensor and the values of the

"Sensor_Parameter" field.

Table 19. Pressure Sensor_Parameter list

Sensor_Parameter field Parameter

0x00

0x01

0x02

Output data rate

Offset

Scale factor

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Table 19. Pressure Sensor_Parameter list (continued)

Sensor_Parameter field Parameter

0xFF

0x02 – 0xFF

Sensor name (read only)

Forbidden - RFU

UM1744

2.4.30 Pressure sensor output data rate

The "Parameter_Value" field for the output data rate setting is 1 byte in length.

Table 20

describes the output data rate supported for the pressure sensor.

Table 20. Pressure sensor output data rate field

“Parameter_Value” field for pressure sensor ODR Output data rate (Hz)

0x00

0x01

0x02

0x03

0x04 – 0xFF

1

7

12.5

25

Forbidden - RFU

2.4.31 Pressure sensor offset

The "Parameter_Value" field for the offset setting is 2 bytes in length and expressed in millibar as signed short (16-bit) with the most significant byte first.

2.4.32 Pressure scale factor

The "Parameter_Value" field for the scale factor setting is 2 bytes in length as signed short

(16-bit) multiplied x1000.

2.4.33 Pressure sensor name

The "Parameter_Value" of the sensor name is a read-only field and it returns the pressure sensor part number (LPS331AP) present on the Discovery-M1.

Table 21

describes the parameters of the temperature sensor and the values of the

"Sensor_Parameter" field.

Table 21. Temperature Sensor_Parameter list

Sensor_Parameter field Parameter

0x00

0x01

0xFF

0x02 – 0xFE

Offset

Scale factor

Sensor name (read only)

RFU

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2.4.35 Temperature sensor offset

The "Parameter_Value" field for the offset setting is 2 bytes in length and expressed in dºC

(tenth of Celsius degrees) as signed short (16-bit) with the most significant byte first.

The "Parameter_Value" field for the scale factor setting is 2 bytes in length (abstract number) as signed short (16-bit) multiplied x1000.

2.4.37 Temperature sensor name

The "Parameter_Value" of the sensor name is a read-only field and it returns the part number sensor, which is the source of the temperature value, present in Discovery-M1.

2.5 Acquisition sensor data frames

Acquisition sensor data frames are frames originated by the software PC (SDK or GUI) to set how to retrieve sensor data from Discovery-M1 and data frames originated by

Discovery-M1 to send sensor data. Acquisition sensor data frames are listed in

Table 22

.

Commands

iNEMO_Set_Output_Mode iNEMO_Set_Output_Mode_

Response iNEMO_Get_Output_Mode iNEMO_Get_Output_Mode_

Response iNEMO_Acquisition_Data

Table 22. Acquisition sensor data frames

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

CONTROL

ACK

NACK

CONTROL

ACK iNEMO_Start_Acquisition iNEMO_Start_Acquisition_Respo nse

NACK

CONTROL

ACK

NACK

DATA

Y

N

N

Y

N

N

N

N

Y

N

0x50

0x50

0x50

0x51

0x51

0x51

0x52

0x52

0x52

0x52

N

N

N

N

N

N

N

N

N

N

Payload Originator

4

Sensors, acquisition frequency, output type, number of samples

PC

0

1

0

4

Error code

Discovery-M1

PC

Sensors, acquisition frequency, output type, number of samples

Discovery-M1

Error code

PC

0

1

1

0 variable

Error Code

Discovery-M1

Sensor

Data

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Commands

Table 22. Acquisition sensor data frames (continued)

Frame

Type

Ack required

Message

ID

QoS

Payload

Length

(in bytes)

Payload Originator

PC iNEMO_Stop_Acquisition iNEMO_Stop_Acquisition_Respo nse

CONTROL

ACK

NACK iNEMO_Get_Acq_Data iNEMO_Get_Acq_Data_Respons e

CONTROL

ACK

NACK

Y

N

N

Y

N

N

0x53

0x53

0x53

0x54

0x54

0x54

N

N

N

N

N

N

0

0

1

0

0

1 Error Code

Discovery-M1

PC

Error Code

Discovery-M1

2.5.1 iNEMO_Set_Output_Mode

The iNEMO_Set_Output_Mode command allows setting which sensors shall be enabled, in which format the data sensor shall be sent from Discovery-M1 to SDK, and other parameters.

Figure 29

shows the frames involved in the iNEMO_Set_Output_Mode transaction.

Figure 29. iNEMO_Set_Output_Mode frames

30/37

When the "AHRS" bit is set to "1", the Discovery-M1 will run the AHRS algorithm, and the

AHRS data (quaternion and roll, pitch, yaw angles) will be sent in the data frame.

When the "COMPASS" field is set to "1", the Discovery-M1 will runs the compass demo, and the compass data (heading, roll and pitch angles) will be sent in the data frames.

The "Cal/Raw" field is used to define how to send sensor data, according to

Table 23

.

Table 23. Calibrated and raw fields

Cal/Raw field Output Data Type

0

1

Calibrated Data

Raw data [LSB]

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The "ACC", "GYRO", "MAG", "PRESS" and "TEMP" fields are used to enable or disable the acquisition of the respective sensors.

The "ASK_DATA" field enables/disables the ask data mode. If this field is set to 1, data will not be sent if not requested by the iNEMO_Get_Acq_Data frame.

The FQx fields are used to set the acquisition rate, according to

Table 24

.

FQ2

1

1

0

1

1

0

0

0

Table 24. Acquisition rate

FQ1 FQ0

0

1

1

0

1

0

0

1

1

0

1

0

1

0

1

0

Acquisition rate (Hz)

1

10

25

50

30

100

400

Synchronized to sensor

If the selected frequency is one of the above values from 1 Hz to 400 Hz, the data acquisition is based on a timer running at the selected frequency and it is not synchronized with any sensors. Otherwise, if the "Acquisition Rate" field is "Synchronized to sensor"

(FQ[2:0] set to ‘111’), the acquisition frequency is synchronized with the ODR (output data rate) of one sensor. In this last case only the selected sensor will run and the other ones will be automatically disabled.

The OTx fields are used to set the interface through which the Discovery-M1 shall send the data. The only interface supported by the actual version of Discovery-M1 is the USB

interface, as shown in

Table 25

.

OT2

0

1

1

1

1

0

0

0

Table 25. Output interface

OT1 OT0

1

0

0

1

1

0

0

1

1

0

1

0

1

0

1

0

Output Interface

USB

RFU

The "Number of Samples" bytes specify how many sensor data samples shall be acquired.

When set to zero (continuous mode), the Discovery-M1 will acquire and send sensor data to the PC until it receives the "iNEMO_Stop_Acquisition" command.

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2.5.2 iNEMO_Get_Output_Mode

The iNEMO_Get_Output_Mode command allows retrieving information from Discovery-M1 about its acquisition settings.

Figure 30

shows the frames involved in the

iNEMO_Get_Output_Mode transaction.

Figure 30. iNEMO_Get_Output_Mode frames

The "Output Mode" fields are described in

Section 2.5.1

.

2.5.3 iNEMO_Start_Acquisition

The iNEMO_Start_Acquisition command allows starting the acquisition of sensor data according to the output settings.

Figure 31

shows the frames involved in the

iNEMO_Start_Acquisition transaction.

Figure 31. iNEMO_Start_Acquisition frames

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The frame counter is an unsigned int (16-bit) incremented every time a new data frame is sent to the PC.

"ACC(X,Y,Z)" represents the accelerometer data field. This data field will be available only if the accelerometer sensor has been enabled ("ACC" field in the "iNEMO_Set_Output_Mode" frame is set to 1). If the "Raw" option is not enabled ("Raw" field in

"iNEMO_Set_Output_Mode" frame is 0), each accelerometer axis value is expressed in mg

(thousandth of gravitational force) in one of the possible ranges defined in

Table 10

, as a signed short value (2 bytes). If the "Raw" option is enabled, each axis value represents the raw sensor data (LSB value).

"GYRO(X,Y,Z)" represents the gyroscope data field. This data field will be available only if the gyroscope sensor has been enabled ("GYRO" field in the "iNEMO_Set_Output_Mode" frame is set to 1). If the "Raw" option is not enabled, each gyroscope axis value is expressed in dps (degrees per second) in one of the possible ranges defined in

Table 18

, as

a signed short value (2 bytes). If the "Raw" option is enabled, each axis represents the raw sensor data (LSB value).

"MAG(X,Y,Z)" represents the magnetometer data field. This data field will be available only if the magnetometer sensor has been enabled ('MAG" field in the

"iNEMO_Set_Output_Mode" frame is set to 1). If the "Raw" option is not enabled, each magnetometer axis value is expressed in mG (thousandth of Gauss) in one of the possible ranges defined in

Table 14

, as a signed short value (2 bytes). If the "Raw" option is enabled,

each axis value represents the raw sensor data (LSB value).

"PRESS" represents the pressure data field. This data field will be available only if the pressure sensor has been enabled ("PRESS" field in the "iNEMO_Set_Output_Mode" frame is 1). If the "Raw" option is not enabled, the pressure value is expressed in c-mbar

(centi-mbar ie. one hundredth of a millibar) in the range [+26000 c-mbar, +126000 c-mbar], as a signed int value (4 bytes). If the "Raw" option is enabled, the pressure data field represents the raw sensor data (LSB value).

"TEMP" represents the temperature data field. This data field will be available only if the temperature sensor has been enabled ("TEMP" field in the "iNEMO_Set_Output_Mode" frame is set to 1). If the "Raw" option is not enabled, the temperature value is expressed in dºC (tenth of Celsius degrees) in the range [-400 dºC, + 1250 dºC], as a signed short value

(2 bytes). If the "Raw" option is enabled, the temperature data field represents the raw sensor data (LSB value).

"RPY" represents the roll, pitch, yaw data field. This data field will be available only if the

"AHRS" option has been enabled ("AHRS" field in the "iNEMO_Set_Output_Mode" frame is

1).

The Roll data is expressed as a floating point value (4 bytes) in the range of ±180 degrees.

The Pitch data is expressed as a floating point value (4 bytes) in the range of ±90 degrees.

The Yaw data is expressed as a floating point value (4 bytes) in the range of ±180 degrees.

"Quaternion" represents the quaternion data field. This data field will be available only if the

"AHRS" option has been enabled ("AHRS" field in the "iNEMO_Set_Output_Mode" frame is

1). Each quaternion data is expressed as a floating point value (4 bytes) in the range ±1.

The Q0 field represents the scalar part of the quaternion, while the Q1, Q2 and Q3 fields represent the vector part of the quaternion.

The "COMPASS" data will be available only if the user enables the "Compass" option

("COMPASS" field in the "iNEMO_Set_Output_Mode" frame is set to 1).

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STEVAL-MKI121V1 frames UM1744

The compass Roll data is expressed as a floating point value (4 bytes) in the range ±90 degree.

The compass Pitch data is expressed as a floating point value (4 bytes) in the range ±90 degree.

The compass Heading data is expressed as a floating point value (4 bytes) in the range

±180 degree.

During the acquisition and data transmission phase it is not possible to use commands that change the sensor settings or the output mode. It is necessary to stop the acquisition before sending these commands.

2.5.4 iNEMO_Stop_Acquisition

The iNEMO_Stop_Acquisition command stops the acquisition and data transmission.

Figure 32

shows the frames involved in the iNEMO_Stop_Acquisition transaction.

Figure 32. iNEMO_Stop_Acquisition frames

2.5.5 iNEMO_Get_Acquired_Data

The iNEMO_Get_Acquired_Data command is used to send the acquired data.

Figure 33

shows the frames involved in iNEMO_Get_Acquired_Data transaction.

Figure 33. iNEMO_Get_Acq_Data frames

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All the error codes used in the NACK frames are listed in

Table 26

.

Table 26. Calibrated and raw fields

“Error Code” field Error

0x00

0x01

0x02

0x03

0x04

0x05

0x06 – 0xFF

Forbidden

Unsupported command

Out-of-range value

Not executable command

Wrong syntax

Discovery-M1 not connected

RFU

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Revision history

Date

23-May-2014

Table 27. Document revision history

Revision Changes

1 Initial release.

UM1744

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