Abstract

The document describes how to set up and use the EVK-NORA-B2 evaluation kits for prototyping NORA-B26 u-connectXpress Bluetooth Low Energy applications.

Document Number: UBXDOC-465451970-4607 - R01 | Disclosure: C1-Public

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Document Information

Product Status

This document applies to the following products:

For information about the hardware, software, and status of the available product types, see the NORA-B26 datasheet [1].

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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 and statuses, visit www.u-blox.com.

Copyright © u-blox AG

1 Product Description

1.1 Overview

The EVK-NORA-B2 evaluation kit provides a versatile development platform for quick prototyping of a variety of low-powered Internet of Things (IoT) applications supporting Bluetooth® using the u-connectXpress software [7].

The u-connnectXpress AT commands manual for NORA-B2, as well as the u-connectXpress User Guide, can be found on NORA-B2 product page [6].

Table 1: Available NORA-B2 evaluation kits

Figure 1: EVK-NORA-B2 evaluation board (top view)

Top view of the EVK-NORA-B26 evaluation board, showing various connectors, components, and labels. Key visible elements include the NORA-B26 module, USB-C port, power switches, various pin headers (e.g., J1, J2, J3, J4, J5, J7, J8, J9, J11, J12, J14, J16, J17, J18, J19), U.FL connector (J1), Li-Ion battery connector (J4), QWIIC connector, debug interface, and multiple LEDs and buttons.

1.2 Kit includes

1.2.1 EVK-NORA-B261

• Evaluation board with NORA-B2x1 module
• USB-C to USB-A cable
• NFC antenna
• 2.4 GHz dipole antenna with U.FL connector

1.2.2 EVK-NORA-B266

• Evaluation board with NORA-B2x6 module
• USB-C to USB-A cable
• NFC antenna

1.3 Key features

EVK-NORA-B2 boards provide:

• u-connectXpress AT command set eliminates need for expertise in Bluetooth protocol stacks
• Support NORA-B2 supply voltage of 3.3 V or 1.8 V
• COM port over USB
• Bluetooth LE central, peripheral, and GATT client/server roles
• Buttons and status LEDs for user interaction
• Power input through USB-C, pin sockets, Li-ion, or coin cell battery
• Current measurement access points from pin headers and jumpers

1.4 Block diagram

Figure 2: EVK-NORA-B2 block diagram

Block diagram of the EVK-NORA-B2, illustrating the NORA-B2 module connected to power (LDO, Li-ion, USB), UART, Buttons, LEDs, NFC, QWIIC, and GPIO pin headers. The diagram shows power inputs from 3.5-6 VDC (Li-ion) and 5 V DC (USB), with internal regulation to 1.8 V and 3.3 V. It also shows connections for UART, USB, Buttons, LEDs, NFC, QWIIC, and GPIO pin headers.

Design files for the EVK-NORA-B26 are available in the u-blox short range EVK design GitHub repository [4].

2 Setting up the evaluation board

Follow the instructions in this section to power up the EVK and prepare it for PC communication and SW development.

2.1 Connect external antenna (EVK-NORA-B261 only)

The NORA-B261 module soldered to the EVK-NORA-B261 requires use of the external antenna provided with the kit, or one of the antennas listed in the NORA-B26 system integration manual [2]. Carefully connect the U.FL connector on the antenna or coaxial jumper to U.FL connector (J1) near the NORA-B261 module.

Figure 3: U.FL connector near module

Close-up view of the U.FL RF coaxial connector (J1) on the EVK-NORA-B26 board, typically used for external antennas.

[warning] U.FL connectors are intended for limited connection cycles.

2.2 Powering up

[warning] Before powering up the EVK-NORA-B261, be sure to connect the 2.4 GHz antenna to the U.FL antenna connector J1. Failing to do so can cause module malfunction.

1. Insert the USB cable into a PC and connect it to the type-c connector, J2, on EVK-NORA-B2.
2. Set the power switch, SW1, to ON.

The green status LED (D19) is lit when the EVK-NORA-B2 has powered up correctly.

[tip] Further powering options for current measurement and use of other power sources are described in Powering options.

2.3 UART interface

The module communicates using AT commands and events over a UART interface provided via the USB port on the EVK.

2.3.1 Serial port device drivers

The host operating system installs the correct COM port drivers automatically. The drivers need to be installed only when you connect the unit to a new computer for the first time. For more information about the COM ports and their configuration, see the FTDI FT231XQ-R Datasheet [3].

Windows OS automatically assigns one COM port to the unit:

• "USB Serial Port" - the module's main UART used for serial communication by default.

2.3.2 Terminal SW

Any terminal application, for example TeraTerm, can be used to verify that the EVK is working as expected. Open the serial port using the default settings:

• 115200 bps
• 8 data bits
• No Parity
• 1 stop bit
• Hardware flow control (RTS/CTS) enabled

When the module starts up a +STARTUP event is expected.

Figure 4: +STARTUP event received and AT Command sent

Screenshot of a terminal application showing a successful '+STARTUP' event and an AT command response 'OK'.

2.3.3 s-center 2 evaluation software

s-center 2 is an easy-to-use tool for evaluating, configuring, and testing u-blox short range modules. Running on Windows 10 or newer operating systems, the software allows end users to assess and configure u-blox short range modules using the EVK.

Download and install the s-center 2 software from the u-blox s-center product page [5].

3 Board configuration

Figure 5: Available connectors

Diagram showing the available connectors on the EVK-NORA-B2 board, labeled with their functions such as USB-C, Power switch, UART, NFC, and U.FL RF coax. Key connectors include J2 (USB-C), J3 (Current measurement), J4 (Li-Ion battery), J7 (Multipurpose GPIO), J12 (NFC), J1 (U.FL RF coax), J2 (UART USB). Switches S1 (Dual switch) and SW1 (Power ON) are also indicated.

3.1 Power

EVK-NORA-B2 is equipped with several connectors for power supply and current measurements.

3.1.1 Power connectors

Table 2: EVK-NORA-B2 connector description

3.1.2 Powering options

Power to the evaluation board can be supplied in several ways as shown in Table 3.

Table 3 EVK powering options

All supplies are protected by reverse voltage diodes and can be connected simultaneously.

3.1.3 Power supply voltage selection

The evaluation board supports both 1.8 V and 3.3 V supply voltage to NORA-B2. To select either 1.8 V or 3.3 V for the NORA-B2 module and other peripherals, set switch SW2 as shown in Figure 6.

Figure 6: Voltage switch SW2

Close-up view of the SW2 voltage selection switch on the EVK-NORA-B2 board, allowing selection between 1.8V and 3.3V.

3.2 Measuring current consumption

Before making current consumption measurements, review the available Powering options to find out which NORA-B2 signals must be isolated for your chosen power configuration.

[tip] If accurate small sleep current supply measurements are performed, make sure only used signals are connected to the module (e.g. disconnect RTS and CTS if they are not used). All connected signals will consume small currents via pull-ups/downs or via pull-ups in combination with small voltage level differences on the input and output side.

3.2.1 Current-sensing header

The evaluation board provides a 3-pin header with a 2.54 mm pitch, J3, for power consumption measurement of the module's VCC supply. The current can be measured either with ammeter or voltage meter as described in Using an ammeter and Using a voltmeter. R46, which is intended to be mounted when measuring the current with a voltage meter, is connected between J3 pin 2 and 3.

Figure 7: Current-sensing header circuits

Circuit diagram illustrating the current-sensing header (J3) connections for measuring module current. It shows the VDD_M and GND connections and the placement for resistor R46.

3.2.2 Using an ammeter

To measure the current, connect the ammeter in series with the power source between pin 2 and 3 of J3. In this way, the current is measured when the NORA module is supplied from either the onboard regulator or an external supply, as shown in Figure 8. Ensure that switch S1 is in the off position for both channels.

3.2.3 Using a voltmeter

The EVK-NORA-B2 board must be modified before the module current can be measured with a voltmeter.

To modify the board, solder low-resistance, high-tolerance, 0603-sized resistors to the footprint labeled R46, as shown in Figure 8. This resistor replaces the jumpers and any current running through it produces a voltage across its terminals. Measure this voltage with the voltmeter and calculate the current using Ohm's law. Ensure that switch S1 is in the off position for both channels.

3.2.4 Using an external power supply or power analyzer

Connect the terminals of the instrument to the EVK pins, as shown in Figure 8. An ammeter can also be added in series. Ensure that switch S1 is in the off position for both channels.

When using a power analyzer that both provides supply voltage and measures current, ensure that other evaluation board peripherals and components are disconnected from this supply. Failure to do so will introduce measurement errors – even if the other components are supplied with the same voltage level from another LDO or source.

To reduce leakage current, use a second external power channel to supply EVK peripherals. This second channel must be on to enable PC communication via the USB port J2. If the built-in USB/UART controller will not be used, the UART signals can be connected to the host directly via the UART pins of J7, see section Serial communication.

Figure 8: Options for measuring module current consumption

Diagrams illustrating options for measuring module current consumption using an ammeter, voltmeter, or external power supply/power analyzer. The diagrams show connections to J3, switch S1, and the optional R46 resistor for voltmeter measurements.

4 Interfaces and peripherals

This section explains how to measure current on the NORA module and introduces the board's interfaces and buttons.

4.1 Buttons

The board provides a RESET button and 2 user buttons (Button 0, and Button 1) that are active-low and connect to GND when pressed.

Figure 9 Reset button location

Image showing the location of the RESET button on the EVK-NORA-B2 board.

Figure 10 User button locations

Image showing the locations of the user buttons (Button 0 and Button 1) on the EVK-NORA-B2 board.

Table 4: User buttons

Two buttons Button0 and Button1 are used to enter bootloader, as shown in Table 5.

Table 5: EVK-NORA-B2 boot mode function

For more details about the update software and the bootloader, see the NORA-B2 system integration manual [2].

4.2 LEDs

Figure LED locations

Image highlighting the locations of various LEDs on the EVK-NORA-B2 board, including power status (D19) and UART status LEDs (D9-D14), and the RGB status LED.

EVK-NORA-B2 includes eight status LEDs and one RGB status LED:

• Power status (D19): Indicates the +3.3V power on the board when lit (green).
• UART1 status (D9-D14): Indicates UART1 signal status under GPIO control, as shown in Table 6.
• System status (RGB1).

Table 6: Status RGB LED indications

4.3 Serial communication

One COM port is available for connecting the UART to PC via the USB connector.

Switch S2 connects the FTDI chip to NORA-B2 UART and pin header if set ON. If switched OFF the corresponding UART signal is only connected between pin header and NORA-B2.

• S2 – OFF. Pin header and NORA-B2
• S2 – ON. FTDI, pin header, and NORA-B2

Table 7 UART pins and socket header connections

Appendix

A Glossary

Table 8: Explanation of the abbreviations and terms used

Related documentation

• NORA-B26 data sheet, UBXDOC-465451970-4608
• NORA-B26 system integration manual, UBXDOC-465451970-3906
• FTDI FT231XQ-R Datasheet, FT231X (ftdichip.com)
• u-blox HW design GitHub repository, https://github.com/u-blox/evk_designs_sho_altium
• s-center product page, https://www.u-blox.com/en/product/s-center
• NORA-B2 product page, https://www.u-blox.com/en/product/nora-b2-series
• u-connectXpress product page, https://www.u-blox.com/en/product/u-connectxpress

For product change notifications and regular updates of u-blox documentation, register on our website, www.u-blox.com.

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