NORA-B26 u-connectXpress

Stand-alone multiradio modules

User guide

This document provides an overview of the u-connectXpress software for u-blox short range modules
and describes how the products can be configured for Bluetooth Low Energy use cases.

Document information

Title	NORA-B26 series u-connectXpress
Subtitle	Stand-alone multiradio modules
Document type	User guide
Document number	UBX-23008692
Revision and date	R01, 25-Aug-2025
Disclosure restriction	C1-Public

 

This document applies to the following products

Product name	Software version
NORA-B26 series	3.0.1

Disclaimer
u-blox or third parties may hold intellectual property rights in the products, names, logos, and designs included in this document. Copying, reproduction, or modification of this document or any part thereof is only permitted with the express written permission of u-blox. Disclosure to third parties is permitted for clearly public documents only.
The information contained herein is provided “as is” and u-blox assumes no liability for its use. No warranty, either express or implied, is given, including but not limited to, with respect to the accuracy, correctness, reliability, and fitness for a particular purpose of the information. This document may be revised by u-blox at any time without notice. For the most recent documents, visit www.u-blox.com.
Copyright © u-blox AG

 

1 Overview

This document describes how to set up and use u-blox short range stand-alone modules with u-connectXpress software for NORA-W36. It explains the functionality of different u-blox short range stand-alone modules and includes examples that describe how to use the software in different environments with AT commands. The document is applicable for Bluetooth® Low Energy (LE), multiradio, and Wi-Fi modules.
Several u-blox short range stand-alone modules support open software variants. For more information about the available options, see the corresponding system integration manuals for u-blox short range stand-alone modules.
For older generation modules like ODIN-W2, NINA-W15 and ANNA-B1, u-connectXpress user guide describe the functionality of these modules.

1.1 Getting started with s-center 2

Downloading and installing

1. Download the latest version of s-center 2
2. Double click the downloaded file and follow the installation instructions
3. Launch s-center 2 when the installation is completed

1.2 Product description

u-blox modules are developed for integration into a vast range of devices that demand a high level of reliability, such as those that are typically used in industrial and medical applications.
These professional grade modules operate over an extended temperature range and are approved for radio type application products in many countries. By choosing to use u-blox short range stand-alone modules, the cost and work involved in developing wireless communication solutions is significantly reduced.

Concept	Definition
Host	In this document, a host refers to the device connected to a u-blox short range stand-alone module  through any of the available physical interfaces. In a real application, the host is typically a microcontroller Unit (MCU) running a customer specific application.
Module	In this document, module refers to a u-blox stand-alone module. A module can also refer to a self-contained unit or item that is linked with similar units of a larger system that performs a defined task.
Remote	device A remote device in a wireless network connecting over the Bluetooth Low Energy interfaces supported in the module.

1.3 Bluetooth modules

u-blox compact and powerful stand-alone, modules are designed for the development of Internet-of-Things (IoT) applications. NORA-B26 modules include an embedded Bluetooth stack and an application for wireless data transfer. The wireless support includes Bluetooth v6.0 (Low Energy).
The modules support point-to-point and point-to-multipoint configurations
They are delivered with u-connectXpress software that provides support for u-blox Bluetooth LE Serial Port Service, Generic Attribute Profile (GATT) client and server, Bluetooth beacons, simultaneous Peripheral and Central roles – all configurable from a host by means of AT commands.

2 Key features

The possibility of replacing serial cables with simple wireless connections is a key feature of u-blox modules. It allows system hosts to transfer data to one another over wireless Bluetooth connections that are established between u-blox modules in Central/Peripheral configuration.
Depending on the module capabilities, data from each host is transferred to local u-blox modules over a serial UART interface.
u-blox modules can be configured to automatically establish new connections and/or accept incoming connections using AT commands. For connected hosts, this means that physical serial cables can be replaced with more convenient wireless solutions.

2.1 Bluetooth GATT connection

NORA-B26 can function as either a Central or Peripheral unit, connecting to devices such as laptops, cellular phones, and tablets using the Generic Attribute Profile (GATT).

2.2 Bluetooth SPS connection

NORA-B26 can function as either a Central or Peripheral unit, connecting to devices such as laptops, cellular phones, and tablets via the u-blox Serial Port Service (SPS).

3 u-connectXpress software

3.1 Software architecture

u-connectXpress software for u-blox short range stand-alone modules makes it easy to integrate Bluetooth and Wi Fi connectivity into both new and existing products.
In several high-end modules, u-connectXpress software contains stacks for the Bluetooth Low Energy (LE). Other module variants support different combinations of these stacks.
The figure below shows the logical components for high-end (NORA-B26) modules.

3.2 Operating modes

NORA-B26 operates in the following modes:

• AT mode (default): AT commands and data can be send at the same time. Data is sent and received in AT commands and events - in string or binary mode
• Transparent Mode (TM): All data sent and received on the UART is connected to the remote device
• Transparent Mode Persistent (TMP): Same as TM, but the connection is established at startup or when the connection is dropped

Additionally, the module supports various low-power modes, which optimize power consumption regardless of the operating mode. See also Low power modes and Power consumption optimization.
Deep sleep is supported with the command AT+UPMDS, see AT command manual and Data sheet for more information.

3.2.1 Changing operating modes

u-blox modules can be configured to start in any operating mode. Once up and running, the modules can be switched between most modes. The modes are changed with a command or escape sequence sent to the module:

• Switch from Command mode to Transparent mode using an AT command
• Switch from Transparent mode to command mode with an escape sequence.

The module is controlled using AT commands in (default) Command mode. In this mode, the host sends control and configuration commands and indicates when data is to be sent over the UART interface.

3.3 NORA-B26 capabilities

u-connectXpress features	Capability in 3.0.1
Chipset	Nordic nRF54L10
Multiradio	Bluetooth Low Energy 6.0
Bluetooth Qualification	TBD
BLE Central connections	6 Peripherals connected
BLE Peripheral connections	2 Centrals connected
BLE Scatternet connections (C+P)	Central with 1 Peripheral connected, advertising and allow incoming connection as Peripheral
BLE Link key storage	30 Devices. The keys that are the least used are removed first when storage is full
Data transfer modes	- Buffer Mode (event and read data) - Direct Mode (data in event) - Transparent mode (like serial port cable replacement) Buffer Mode is Default, Transparent mode only supports one link. Transparent Mode has highest throughput, then Direct Mode and then Buffer Mode
SPS MTU size	244 bytes, 1000 bytes can be sent in AT command

 

More information about the AT commands used in this use cases can be found in the NORA-B26 AT command manual.

4 Bluetooth use cases

The following Bluetooth Low Energy use case, show some functionality to get started with GATT client, GATT server and SPS.

u-connectXpress BLE default values	3.0.1
BLE Mode default	ON, Central and Peripheral (3)
BLE Legacy Advertising default	OFF, enable with AT+UBTAL

The following examples use the MAC address below, this must be replaced by the real MAC address of the devices that are used.

• Peripheral MAC address: AAAAAAAAAAAA
• Central MAC address: BBBBBBBBBBB

4.1 Bluetooth GATT client

This use case configures NORA-B26 as a Central device that operates as a GATT client and receives data.

This use case configuration is used in combination with Bluetooth GATT server.
 

Nr	Instructions	AT command	AT event
1	Check that Bluetooth Central is enabled. 1: Central or 3: Central and Peripheral. If so jump to step 6.	AT+UBTM?	+UBTM:1 or +UBTM:3
2	Enable Bluetooth 1: Central or 3: Central and Peripheral	AT+UBTM=1 or AT+UBTM=3
3	Store command	AT&W
4	Restart	AT+CPWROFF
5	Wait for NORA-B26 to startup		+STARTUP
6	Connect to remote device	AT+UBTC=AAAAAAAAAAAAp	+UEBTC:0,AAAAAAAAAAAAp
7	Discover Services and look for 180D, which is the descriptor for the Heart Rate service.	AT+UBTGPSD=0	+UBTGPSD:0,12,65535,180D
8	Discover all Service Characteristics and look for 2A37, which is the descriptior for the Heart Rate Measurement characteristics.	AT+UBTGSCD=0,12,65535	+UBTGSCD:0,13,10,14,2A37
9	Use the Value handle, which in this case is 14. The value can vary. Look for 2902, which is the descriptor for the notification.	AT+UBTGCDD=0,14,15	+UBTGCDD:0,13,15,2902
10	Enable notification on the GATT Client the Central in this example	AT+UBTGCCW=0,15,1
11	Notification is received on the GATT Client		+UEBTGCN:0,14,60 +UEBTGCN:0,14,61 +UEBTGCN:0,14,62

4.2 Bluetooth GATT server

This use case configures NORA-B26 as a Peripheral device that operates as GATT server and sends notifications.

This configuration works in combination with Bluetooth GATT client.
 

Nr	Instructions	AT command	AT event
1	Check that Bluetooth Peripheral is enabled 2: Peripheral and  3: Central and Peripheral. If so jump to step 6.	AT+UBTM?	+UBTM:2 or +UBTM:3
2	Enable Bluetooth 2: Peripheral or 3: Central and Peripheral	AT+UBTM=2 or AT+UBTM=3
3	Store command	AT&W
4	Restart	AT+CPWROFF
5	Wait for NORA-B26 to start		+STARTUP
6	Enable Legacy Advertising	AT+UBTAL
7	Write the Heart Rate service	AT+UBTGS=180D	+UBTGS:21
8	Write the GATT characteristic	AT+UBTGC=2A37,3A,01,01,00	+UBTGC:30,31
9	Activate GATT Service	AT+UBTGSA
10	Wait for incoming Bluetooth connection		+UEBTC:0,BBBBBBBBBBB
11	Get the MTU for the connection (optional)	AT+UBTCST=0,3	+UBTCST:3,247
12	Get the Role for the connection (optional)	AT+UBTCST=0,7	+UBTCST:7,1
13	Send a notification from the GATT Server using the value handle	AT+UBTGNS=0,14,60 AT+UBTGNS=0,14,61 AT+UBTGNS=0,14,62

4.3 Bluetooth SPS central

This use case configures NORA-B26 as a Central device that sends and receives data from another NORA-B26 module operating as a Peripheral device. The communication between the two modules is facilitated using the proprietary u-blox Serial Port Service. It is also possible to connect to other devices that supports the SPS protocol.
This use case operates in combination with Bluetooth SPS peripheral.
 

Nr	Instructions	AT command	AT event
1	Check that Bluetooth Central is enabled. 1:Central or 3:Central and Peripheral. If so, jump to step 6.	AT+UBTM?	+UBTM:1 or +UBTM:3
2	Enable Bluetooth 1:Central or 3:Central and Peripheral	AT+UBTM=1 or AT+UBTM=3
3	Store command	AT&W
4	Restart	AT+CPWROFF
5	Wait for NORA-B26 to start		+STARTUP
6	Initiate Bluetooth discovery. Listen for advertising packets broadcast from Peripheral device.	AT+UBTD	+UBTD:AAAAAAAAAAAAp,-52,"NORA-B26-AAAAAA",0,10094E4F52412D5733362D414141414141
7	Connect Bluetooth	AT+UBTC=AAAAAAAAAAAAp	+UEBTC:0,AAAAAAAAAAAAp
8	Read MTU, maximum data size	AT+UBTCST=0,3	+UBTCST:3,247
9	Read RSSI (optional)	AT+UBTRSS=0	+UBTRSS:-52
10	Connect SPS using handle of Bluetooth connection	AT+USPSC=0
11	SPS connection is up		+UESPSC:0
12	It is now possible to send and receive SPS data in String or Binary mode
13	Disconnect the SPS and Bluetooth connection	AT+UBTDC=0	+UESPSDC:0 +UEBTDC:0

4.4 Bluetooth SPS peripheral

This use case configures NORA-B26 module as a Peripheral device that sends and receives data from another NORA-B26 module operating as a Central device. The communication between the two modules is facilitated using the proprietary u-blox Serial Port Service. It is also possible to connect to other devices that support the SPS protocol.
This use case configuration is used in combination with Bluetooth SPS central.
 

Nr	Instructions	AT command	AT events
1	Check that Bluetooth Peripheral is enabled.  2: Peripheral and  3: Central and Peripheral. If so, jump to step 6	AT+UBTM?	+UBTM:2 or +UBTM:3
2	Enable Bluetooth  2: Peripheral or  3: Central and Peripheral	AT+UBTM=2 or AT+UBTM=3
3	Store command	AT&W
4	Restart	AT+CPWROFF
5	Wait for NORA-B26 to startup		+STARTUP
6	Enable SPS on Peripheral	AT+USPS=1
7	Enable Legacy Advertising	AT+UBTAL
8	Peripheral receives Incoming Bluetooth connection		+UEBTC:0,BBBBBBBBBBBBp
9	Read MTU, maximum data size on both	AT+UBTCST=0,3	+UBTCST:3,247
10	Read RSSI (optional)	AT+UBTRSS=0	+UBTRSS:-52
11	Central Connect SPS using handle of Bluetooth connection	AT+USPSC=0	+UESPSC:0
12	It is now possible to send and receive SPS data in String or Binary mode
13	SPS and Bluetooth link is down		+UESPSDC:0 +UEBTDC:0

4.5 Bluetooth advertise

This use case configures NORA-B26 as a peripheral device that operates as a GATT client and receives data.

This use case configuration is used in combination with Apple iPhone using the The Apple Notification Center Service (ANCS).

Nr	Instructions	AT command	AT event
1	Check that Bluetooth Peripheral is enabled  2: Peripheral and 3: Central and Peripheral. If so, jump to step 6.	AT+UBTM?	+UBTM:2 or +UBTM:3
2	Enable Bluetooth 2: Peripheral or 3: Central and Peripheral	AT+UBTM=2 or AT+UBTM=3
3	Store command	AT&W
4	Restart	AT+CPWROFF
5	Wait for NORA-B26 to start		+STARTUP
6	Set Apple ANCS Advertise data packet	AT+UBTAD=1115D0002D121E4B0FA4994ECEB531F40579
7	Enable Legacy Advertising	AT+UBTAL
8	Peripheral receives Incoming Bluetooth connection		+UEBTC:0,BBBBBBBBBBBBp
9	Discover Services and look for 180A that is the Device Information	AT+UBTGPSD=0	+UBTGPSD:0,1,5,1800 +UBTGPSD:0,6,9,1801 +UBTGPSD:0,10,14,180A +UBTGPSD:0,15,19,D0611E78BBB44591A5F8487910AE4366 +UBTGPSD:0,20,24,9FA480E0496745429390D343DC5D04AE +UBTGPSD:0,25,28,180F +UBTGPSD:0,29,34,1805 +UBTGPSD:0,35,44,7905F431B5CE4E99A40F4B1E122D00D0 +UBTGPSD:0,45,56,89D3502B0F36433A8EF4C502AD55F8DC
10	Discover all Service Characteristics and look for the attribute 2A29, which describes the Manufacturer Name String characteristics	AT+UBTGSCD=0,10,14	+UBTGSCD:0,11,02,12,2A29 +UBTGSCD:0,13,02,14,2A24
11	Read the Manufacturer Name String Apple Inc. characteristics on handle 12	AT+UBTGR=0,12	+UBTGR:0,12,4170706C6520496E632E (Apple Inc.)

4.6 Bluetooth security

Pairing

• Pairing is the initial process where two Bluetooth devices exchange information necessary to establish an encrypted connection
• During pairing, devices negotiate security parameters, such as encryption keys and authentication methods
• It ensures that communication between devices remains confidential and secure
  Think of pairing as the handshake that sets the foundation for a secure link

Bonding

• Bonding occurs after successful pairing
• It involves storing the information from the pairing process on both devices
• Once bonded, devices remember each other’s security credentials (keys) for future reconnections
• Bonding eliminates the need to repeat the pairing process every time the devices reconnect
• Essentially, bonding creates a permanent security relationship between the devices

In summary

• Pairing: Establishes the initial secure connection
• Bonding: Ensures that the devices remember each other’s security details for subsequent interactions
• Remember, these processes are essential for maintaining the confidentiality and integrity of data exchanged over Bluetooth connections

4.7 Bluetooth security initiator

Bluetooth Security is by disabled default and must be configured and enabled before use.

Nr	Instructions	AT command	AT event
1	Set Bluetooth I/O Capabilities to Display Yes/No (2)	AT+UBTIOC=2
2	Set Only allow authenticated bonding with encrypted Bluetooth link (3)	AT+UBTBSM=3
3	Allow Pairing	AT+UBTPM=1
4	Bluetooth Bond	AT+UBTB=BBBBBBBBBBBBp
5	Bluetooth Connected event		+UEBTC:0,BBBBBBBBBBBBp
6	Bluetooth User Confirmation event, check the numer on both devices, should be the same		+UEBTUC:BBBBBBBBBBBBp,786920
7	Bluetooth User Confirmation, confim with yes	AT+UBTUC=BBBBBBBBBBBBp,1
8	Bluetooth Bond success		+UEBTB:BBBBBBBBBBBBp,0
9	Bluetooth Bonded Devices List (optional)	AT+UBTBDL	+UBTBDL:BBBBBBBBBBBBp

4.8 Bluetooth security responder

Bluetooth Security is by disabled default and must be configured and enabled before use.

Nr	Instructions	AT command	AT event
1	Check that Bluetooth Peripheral is enabled, 2: Peripheral or 3: Central and Peripheral, if so move to step 6	AT+UBTM?	+UBTM:2 or +UBTM:3
2	Enable Bluetooth 2: Central or 3: Central and Peripheral	AT+UBTM=1 or AT+UBTM=3
3	Store command	AT&W
4	Restart	AT+CPWROFF
5	Wait for NORA-B26 to startup		+STARTUP
6	Enable Legacy Advertising	AT+UBTAL
7	Set Bluetooth I/O Capabilities to Display Yes/No (2)	AT+UBTIOC=2
8	Set Only allow authenticated bonding with encrypted Bluetooth link (3)	AT+UBTBSM=3
9	Allow Pairing	AT+UBTPM=1
10	Bluetooth Connected event		+UEBTC:0,AAAAAAAAAAAAp
11	Bluetooth User Confirmation event, check the numer on both devices, should be the same		+UEBTUC:AAAAAAAAAAAAp,786920
12	Bluetooth User Confirmation, confim with yes	AT+UBTUC=AAAAAAAAAAAAp,1
13	Bluetooth Bond success		+UEBTB:AAAAAAAAAAAAp,0
14	Bluetooth Bonded Devices List (optional)	AT+UBTBDL	+UBTBDL:AAAAAAAAAAAAp

 

5 Power save use cases

5.1 Auto sleep

By default no lower power mode is enabled in NORA-WB26 to have maximal performance and response time.
In some application power consumption is important and data throughput and latency is not that important. By enabling the low power mode this will slighty change. More power save means more latency can be expected.
Power level 0 (default, no power save) and power level 1 (moderate power save) is supported, more levels may be added in future releases.

The low power level 1 is set using the command AT+UPMPSL=1 see NORA-B26 SIM and AT command manual for more details. There is a limitation that the first AT command after the timeout (default 1 second) can't be longer than 16 bytes.
Note that in power level 1 only 115200 baud rate or lower is allowed.

All low power modes save power automatically and will adjust this depending on the level.
When enabled, no further action is required by the host.

5.2 Deep sleep

The most efficiant power level is Deep sleep which is almost like a power off, no radio communication is possible in this mode.

• To initiate Deep sleep mode, the host uses the AT command AT+UPMDS
• To wake up the module from Deep sleep mode, the host sets GPIO_J9 to GND
• After wake up, the module assumes the same state as it does after a reset

6 Send and receive data

NORA-B26 supports several modes for sending and receiving data:

• String mode
  • All readable ASCII characters (0x21-0x7E, 0xA1-0xFF)
  • Use when sending data in plain text format. For example, when using JSON, HTML, or NMEA.
• Binary mode
  • All types of characters (0x00-0xFF)
  • Use when all types of data is needed. For example, in binary content using file upload and download.
• Transparent mode
  • All types of characters (0x00-0xFF)
• Transparent mode has best performance, due to no wait states
• Direct mode is faster than Buffered mode
• Binary mode is faster than String mode

To receive data without an event and read it out, the read mode can be changed to direct mode AT+USORM=1

6.1 String mode

SPS Receive data mode

Syntax
AT+USPSRM=<receive_mode>

• 0: Buffered mode
  • +UESPSDA SPS Data Available event, default mode
• 1: Direct string mode
  • +UESPSDS - SPS Data String event

6.1.3 SPS write string

Syntax
AT+USPSWS=<conn_handle>,<string_data>

Example to write SPS data

Nr	Instructions	AT command	AT event
1	Write SPS data in string format size	AT+USPSWS=0,"Hello from NORA-B26"

6.1.4 SPS read string

Syntax
AT+USPSRS=<sps_handle>,<length>
+USPSRS:<sps_handle>,<length>,<string_data>

Example to read SPS data

Nr	Instructions	AT command	AT event
1	Incoming SPS data		+UESPSDA:0,19
2	Reads incoming SPS data in string format	AT+USPSRS=0,19	+USPSRS:0,19,"Hello from NORA-B26"

6.2 Binary mode

The binary mode should be used when binary content is transmitted, like files and binary protocols.

See Binary data for more infomation about the format of the data.

SPS receive mode

Syntax
AT+USPSRM=<receive_mode>

• 0: Buffered mode
  • +UESPSDA SPS Data Available event, default mode
• 2: Direct binary mode
  • +UESPSDB - SPS Data Binary event

See more infomation about Binary Data.

6.2.3 SPS write binary

Syntax
AT+USPSWS=<conn_handle>{binary_data}
 

Example to write SPS data

Nr	Instructions	AT command	AT event
1	Write SPS data in binary format size	AT+USPSWB=0\x01\x00\x13Hello from NORA-B26

6.2.4 SPS read binary

Syntax
AT+USPSRB=<sps_handle>,<length>

+USPSRB:<sps_handle>{binary_data}
 

Example to read SPS data

Nr	Instructions	AT command	AT event
1	Incoming SPS data		+UESPSDA:0,19
2	Reads incoming SPS data in binary format	AT+USPSRB=0,19	+USPSRB:0\x01\x00\x13Hello from NORA-B26

6.3 Transparent mode

Transparent mode (TM) works in the same way as Data mode in legacy products. Note that only one connection of SPS (BLE) is allowed.

6.3.1 Transparent mode

To enter Transparent Mode the AT command AT+UTM is used with the option to use SPS.

Syntax
AT+UTM=<link_type>,<handle>

Example for SPS:
AT+UTM=0,0
OK
Transparent mode has started
+++
OK
Back in AT mode

Until the escape secqence +++ is sent, all data received on the UART will be sent unmodified to the remote device on the specific connection selected.

6.3.2 Transparent mode persistent

Like the Transparent Mode (TM) the Transparent Mode Persistent (TMP) works in the same way as Data Mode in legacy u-blox short range products. Note that only one connection of SPS (Bluetooth LE) is allowed in this mode.
The only difference with TM and TMP is that TMP can be stored in flash and connect at startup.

To enter TMP, the AT+UTMP command is used - with the option to use SPS.

Syntax
AT+UBTP=<bd_addr>,<connect_sps>
AT+UTMP=<link_type>,<config_id>

Example for SPS

Nr	Instructions	AT command	AT event
1	Enter the remote Bluetooth LE address to connecting device	AT+UBTP=BBBBBBBBBBBB,1	+UBTP:200
2	Enable Persistant on the connection	AT+UTMP=0,200
3	Store settings	AT&W
4	Reset the module	AT+CPWROFF
5	Wait for NORA-B26 to startup		+STARTUP
6	Transparent Mode Persistent has started
7	Exit Transparent Mode using escape sequence	+++

Until the escape sequence +++ is sent, all data received on the UART will be sent unmodified to the remote device on the specific connection selected.

 

7 Binary data

The packet starts with \x01 (SOH, Start Of Header) followed by the length of the data in two-byte unsigned integer (UINT16) format, and then followed by the binary data.
The data shall not be terminated with the normal \x0D (Carriage Return, \r).

The binary header is comprised of three bytes:
0x01(SOH Start Of Header), MSB_datalength, LSB_datalength

All commands and Unsolicited Result Codes (URC) that use binary data are "complete" without the binary data. In most cases, the binary data is sent directy after the AT command and the handle.

In the following AT+USPSWS - SPS Write Binary command example, the binary data follows the the SPS handle directly - without "," or "\r" or any other character in between.

Example:
AT+USPSWS=0{0x01,0x00,0x02,0xFF,0xEE}
This command writes to sps_handle 0, 2 bytes data the data is 0xFF 0xEE.
Note that the "{ }" should not be included in the data, it is only in this example, showing the binary data content.

7.1 Binary mode command example

To send the following Hello from NORA-B26 message, the content must have a length of 19 bytes. The length in UINT16 format is \00\x13.

AT+USPSWS=0\x01\x00\x13Hello from NORA-B26

Note that the AT command must not be terminated with the \r, The length shown in the header defines the number of bytes expected from the AT parser. The complete AT event includes the same three bytes header immediately after the handle in the event, like this: 
+USPSRB:0\x01\x00\x13Hello from NORA-B26

Note that the AT command must not be terminated with the \r. The length of the header defines the number of bytes expected from the AT parser.

7.2 Python pseudo code example

byte = 'AT+USPSWS=00x01,0x00,0x02,0xFF,0xEE'

byte += b'\x01'

byte += len(bin_data).to_bytes(2, 'big')

byte += bin_data # bin_data contains the binary data to be sent

write(byte)
 

7.3 C# Pseudo code example

byte[] bin_data' //data contains the binary data to be sent

byte[] dataHeader = new byte[3];

dataHeader[0] = 0x01;

dataHeader[1] = Convert.ToByte(bin_data.Length >> 8);

dataHeader[2] = (Convert.ToByte(bin_data.Length & 0xff));

write("AT+USECUB=0,"ca.pem")

write(dataHeader)

write(bin_data)
 

 

8 Error codes

The Extended error codes can be useful to understand the reason for the ERROR received.

Note that the error codes should only be used for information and might change between versions in the future.

8.1 Extended error code

AT+USYEC

Syntax
AT+USYEC?

+USYEC:<error_code>

Example
AT+USYEC?

+USYEC:5

OK

The error code for 5 is U_ERROR_COMMON_INVALID_PARAMETER, meaning that the parameter on the last AT command was invalid.
See NORA-B26 u-connectXpress Error codes for more details.

8.2 Extended error codes on/off

This command will enable the error code when an ERROR is received for every commands.

Syntax
AT+USYEE=<extended_errors>

Example
AT+USYEE=1

OK

AT+

ERROR:32

The error code for 32 is U_AT_STATUS_INVALID_COMMAND, meaning that the AT command is not correct.
See NORA-B26 u-connectXpress Error codes for more details.

9 Software update

This use case shows what AT commands to send to start a software update.
There are two ways to start the software update:

• See more about the XMODEM protocol here

9.1 Update software by AT command

• Enter XMODEM mode for u-connect software update using serial port
• XMODEM-1K and baud rate up to 3 Mbps is supported.

Nr	Instructions	AT command	AT event
1	Start XMODEM protocol with AT command	AT+USYFWUS=921600
2	Now NORA-B26 is ready to receive the software using the XMODEM or  XMODEM-1K protocol		CCCCCCCCCCC...
3	When the software has been downloaded the module will restart	+STARTUP
4	Check the version of the software	AT+GMR	"3.0.0-001"

9.2 Update software by bootloader

Consider the following points when updating the software using the bootloader:

• Enter the bootloader command line mode using serial port by AT command
• Press SWITCH_1 and SWITCH_2 during startup (or after reset)
• A command must be sent within 10 seconds when in bootloader command line mode. Otherwise, the device reboots in normal mode
• For the complete list of available commands, enter ?
• An XMODEM protocol timeout is invoked after 10 seconds if nothing is received
• XMODEM-1K and baud rate up to 3 Mbps is supported

Nr	Instructions	AT command	Event
1a	Enter the bootloader	AT+USYBL=115200
1b	Alternatively, press SWITCH_1 and SWITCH_2 during startup or reset to enter the bootloader reset
2	Wait for the > prompt		>
3	Change baud rate to up to 1 Mbit/s (optional)	r 1000000
4	Start XMODEM protocol with the command x	x
5	Now NORA-B26 is ready to receive the software using the XMODEM or XMODEM-1K protocol		CCCCCCCCCCC...
6	Wait for the prompt to indicate that the software has been downloaded successfully		>
7	Enter the q command to restart the module	q
8	Wait for the prompt to display that the module has restarted in AT mode	+STARTUP
9	Check the version of the software	AT+GMR	"3.0.1-001"

10 Changelog

All notable changes in the NORA-B26 AT commands manual will be documented here.

[3.0.1] - R01 - 2025-08-25

First release for NORA-B26 based on the same fuctionallity as NORA-W36 3.0.0 with Bluetooth use cases using the new and improved AT command set, not backwards compatible with previous u-connectXpress versions.

11 Related information

NORA-B26 product page, https://www.u-blox.com/en/product/NORA-B2-series
s-center 2 webpage, https://www.u-blox.com/en/product/s-center
NORA-B26 AT command manual, https://www.u-blox.com/en/sho-online-documentation/NORA-B26/at-manual
NORA-B26 Error codes,https://www.u-blox.com/en/sho-online-documentation/NORA-B26/error-codes

12 Contacts

u-blox AG
Address: Zürcherstrasse 68
8800 Thalwil
Switzerland
For further support and contact information, visit us at www.u-blox.com/support.