BL653μ Series - Bluetooth 5.1 + 802.15.4 + NFC Modules

Recommended for New Design (RND)


Reliable Bluetooth Connectivity for the IoT - Just a Fraction of the Size. 

Laird Connectivity’s latest range of Nordic nRF52833 based modules specifically targets OEMs where space is constrained in their designs. Yet still the miniaturized BL653μ series enables Industrial OEMs to robustly implement longer range Bluetooth LE applications in the harshest operating environments. This series of secure, low power microcontroller modules with multi wireless capabilities is the future of wireless Internet of Things (IoT) connectivity, as small as 6.3 x 5.6 mm

Powered by Nordic’s nRF52833 WLCSP silicon, the small form factor BL653μ modules provide for secure, robust Bluetooth Low Energy and a Cortex -M4F CPU for any OEM’s product design. The BL653μ provides you with maximum development flexibility with programming options for the Nordic SDK or Zephyr RTOS, a simple, intuitive AT command set, as well as Laird Connectivity’s own smartBASIC environment.

The BL653μ series brings out key nRF52833 hardware features and capabilities including USB access, up to +8 dBm transmit power, up to 5.5V supply considerations, and NFC tag (type 2 / 4) implementation. Complete regulatory certifications enable faster time to market and reduced development risk completes Laird Connectivity’s simplification of your next small form factor Bluetooth design!

Ultra-Compact and Highly Flexible

Our BL653μ Series modules bring reliably, high-quality Bluetooth 5.1 to our smallest form factor ever. With an optional chip antenna or antenna trace pin, they provide multiple ways to connect and develop at an incredibly small size. 

  • Chip Antenna (453-00059) - 6.3 x 8.6 x 1.6 mm
  • Trace Pin (453-00060) - 6.3 x 5.6 x 1.6 mm
BL653µ Size Comparison - Integrated Antenna and Antenna Trace Pin Module


Bluetooth Version
Chipset (Wireless)
Nordic nRF52833 WLCSP
Antenna Options
Chip Antenna (453-00059)
Trace Pin (453-00060)
Data Rate
1 MBps, 2 Mbps, 125 Kbps
Development Tools
UwTerminal X and UWFlashX (multi-platform)
Nordic nRFConnect (Android/iOS Application)
6.3 x 8.6 x 1.6 mm (Integrated Antenna Module)
6.3 x 5.6 x 1.6 mm (Trace Pad Module)
Firmware Upgrade
Frequency Range (Max)
2.480 MHz
Frequency Range (Min)
2.402 MHz
Link Budget
103 dB (@ LE 1 MBps)
111 dB (@ LE 125 Kbps)
Power Consumption
Max Peak Radio Current (@ +8 dBm TX) - 14.1 mA (DCDC at 3V)
Max Peak Radio Current (@0 dBm TX) - 4.9 mA (DCDC at 3V)
Receive Sensitivity
-96 dBm (typical @ LE 1 Mbps)
-103 dBm (typical @ LE 125 Kbps)
smartBASIC, Zephyr RTOS, Nordic SDK, AT Command Set
Temperature Range
-40° to +105° C
Thread and Zigbee support via Nordic nRF Connect SDK
Thread supported via Zephyr RTOS
Transmit Power
+ 8 dBm
1.7V - 5.5V
Antenna Type Bulk or Single Packaging
453-00059C Integrated Antenna Bulk Cut Tape
Antenna Type Bulk or Single Packaging
453-00059R Integrated Antenna Bulk Tape/Reel
Antenna Type Bulk or Single Packaging
453-00060C Trace Pin Bulk Cut Tape
Antenna Type Bulk or Single Packaging
453-00060R Trace Pin Bulk Tape/Reel
Additional Description
453-00062-K1 USB-SWD Programming Kit: Includes mainboard, TC2050-IDC Tag Connect cable, 10-pin flat IDC cable, 1.2 m USB cable, and 2-pin jumper

Photo Gallery






Certified Antennas

  • Learn More
  • FlexPIFA and FlexPIFA 6E


    FlexPIFA / FlexPIFA 6E Flexible Adhesive-Backed PIFA Internal Antennas

    Industry-first, flexible, planar inverted-F antennas for curved surfaces.

    2.5-3 dBi gain.

    Available in 2.4 GHz, dual-band 2.4/5 GHz and Wi-Fi 6E 2.4/5/6 GHz.

    Learn More
  • mFlexPIFA Antenna


    mFlexPIFA Flexible Adhesive-Backed PIFA Internal Antenna

    FlexPIFA antenna for metal mounting with minimal detuning. 2.4 GHz and dual-band 2.4/5.5 GHz with 2 dBi of gain. 

    Learn More
  • NFC Flex PCB Antenna


    NFC Flex PCB Antenna
    Learn More

Become a Laird Connectivity Customer and Gain Exclusive Access to Our Design Services Team

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  • Worldwide EMC testing / certifications
  • Embedded RF hardware / firmware design
  • Cloud architecture and integration
  • Mobile application development
  • Product & Industrial Design

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Name Part Type Last Updated
Datasheet - BL653μ Series All Datasheet 10/14/2021
Product Brief - BL653μ Series All Product Brief 10/11/2021
PCB Footprints (DXF and Altium Format) - BL653μ Series All Technical Drawings 10/13/2020
SCH Symbols (Altium Format) - BL653μ Series All Technical Drawings 10/13/2020
3D Model - BL653μ (453-00059) All Technical Drawings 09/25/2020
3D Model - BL653μ (453-00060) All Technical Drawings 09/25/2020
Application Note - BL653µ Series - Low Power Modes All Application Note 10/13/2020
Application Note - Using Direct Test Mode - BL653µ Series All Application Note 07/21/2021
AS/NZS Certifications - BL653µ All Certification 12/08/2020
EU Certifications - BL653µ All Certification 12/08/2020
FCC Certifications - BL653µ All Certification 12/08/2020
ISED (Canada) Certifications - BL653µ All Certification 12/08/2020
MIC Certifications - BL653µ All Certification 12/08/2020
User Guide - BL653 and BL653µ smartBASIC Extensions Guide v30.2.2.0 All Documentation 01/12/2021
Application Note - Upgrading BL653/BL653µ Firmware via JTAG All Application Note 01/12/2021
Application Note - Upgrading BL653/BL653µ Firmware via UART All Application Note 01/12/2021
Datasheet - NFC Flex PCB Antenna All Documentation 06/18/2021
Application Note - How to Set Up vSP Service - BLxx All Application Note 07/31/2020
Firmware - BL653/BL653µ v30.2.2.0 All Software 01/13/2021
BL65x Zephyr Tutorials - GitHub (External Link) All Documentation 01/13/2021
BL653/BL653µ Applications - GitHub (external link) All Software 01/13/2021
Regulatory Information - BL653u All Certification 09/09/2021
BL653/BL653u Firmware for Upgrade v30_2_3_0 All Software 01/27/2021
User Guide - BL65x AT Interface Application All Documentation 04/21/2021
Quick Start Guide - BL65x AT Interface All Documentation 02/12/2021
User Guide - BL653 and BL653µ smartBASIC Extensions Guide v30.2.3.0 All Documentation 03/26/2021
smartBASIC Applications Migration Guide - BL65x All Documentation 03/09/2021
Release Notes - BL653/BL653µ v30.2.3.0 All Documentation 03/25/2021
Application Note - Bootloader UART Protocol - BL6xx All Application Note 08/16/2021
ISED ICES-003 Issue 7 Declaration of Compliance All Certification 05/18/2021
Application Note - GATT Table with AT Interface Application All Application Note 06/09/2021
PCN 8J-2021 - BL653/BL653µ/BL654 All Documentation 09/07/2021
User Guide - smartBASIC Core Functionality v3.4 All Documentation 06/22/2020


Getting ERROR: JLinkARM DLL not found. Please reinstall latest JLinkARM when trying to flash BL65x module via the JTAG interface. How can this be resolved?

If you are getting ERROR: JLinkARM DLL not found. Please reinstall latest JLinkARM, you will need to download and install the updated Segger drivers for the J-Link.
Segger J-Link Drivers

Do BL65x modules support Boundary Scan function?

Unfortunately, we do not offer Boundary Scan functionality on the BL65x modules.

We do understand it is harder to place and recommend during development the use of an X-ray or some other means to verify to soldering process.

Do you have a smartBASIC example for Android or iOS devices such as smartphones or tablets?

smartBASIC is a programming language developed for our BT900 and BL6xx modules to simplify the code required for programming them. It is not used for developing Android or iOS device applications. BLE applications for Android and iOS devices would need to written in code specific to the Android or iOS platform.

Our, Laird Toolkit Application available for iOS and Android is currently in the process of being updated for Android and iOS to work with newer OS platforms.
Once it is complete we expect to make the source code available, to customers working with our smartBASIC modules, for reference when developing Apps for these platforms.
As of the writing of this FAQ the current version of the Laird Toolkit is still available on the App store for iOS and Google Play for Android, however, it may not work with newer versions of iOS or Android until the updates have been made.
Google Play Store
Apple Store

An alternate resource, the Nordic nRF Toolbox is also available from the iOS App Store and Google Play. The source code for this application is available from Nordic's Website.
nRf Toolbox

How do you change the BAUD rate in the AT Interface Application for BL65x smartBASIC modules?

The default baud rate in the AT Interface application is 115200. In order to change the baud rate within the AT Interface code there are two modifications required in the AT Interface files as shown below:

  1. Locate the following settings within the $autorun$ file which sets the baud to 115200 (highlighted):
    #define SREGINIT_VAL32_0 "\4C\1D\00\00\98\3A\00\00\00\C2\01\00\00\20\00\00\01\20\00\00"
    #define SREGINIT_MIN32_0 "\4C\1D\00\00\4C\1D\00\00\B0\04\00\00\01\00\00\00\01\00\00\00"
    #define SREGINIT_MAX32_0 "\1E\04\3D\00\1E\04\3D\00\40\42\0F\00\FF\FF\00\00\FF\FF\00\00"

    Modify the settings to set the Hex value for the desired BAUD rate in little endian format
    The example below will set it to 9600 baud (0x00 0x00 0x25 0x80)  as shown below (highlighted)
    #define SREGINIT_VAL32_0 "\4C\1D\00\00\98\3A\00\00\80\25\00\00\00\20\00\00\01\20\00\00"
    #define SREGINIT_MIN32_0 "\4C\1D\00\00\4C\1D\00\00\B0\04\00\00\01\00\00\00\01\00\00\00"
    #define SREGINIT_MAX32_0 "\1E\04\3D\00\1E\04\3D\00\40\42\0F\00\FF\FF\00\00\FF\FF\00\00"
  2. Locate the settings for S Register 302 in the $LIB$ file: Modify the settings in #cmpif 0x00010000 : rc=BleEncode32(SregCache32$[0],115200,offset) to set the baud rate to the desired baud rate.


What could be causing additional power draw when in standby doze state?

There are several functions within an application that can increase current consumption above the measurement indicated in the Datasheet for standby doze, low power mode.

  • Timers
  • GPIOs held in an asserted state
  • LEDs
  • Nested functions - which keep the module from entering the standby doze state
  • UART (when open)


Is there protection from Hacking when using smartBASIC modules?

Our Bluetooth 5.0 smartBASIC modules (BL652, BL653, BL654) have the capability of supporting LE Secure Connections Pairing as well as encryption. LE Secure Connection is an enhanced security feature introduced in Bluetooth v4.2. It uses a Federal Information Processing Standards (FIPS) compliant algorithm called Elliptic Curve Diffie Hellman (ECDH) for key generation. 
LE Secure Connections, supports four association models: 

  • Just Works
  • Numeric Comparison (Only for LE Secure Connections)
  • Passkey Entry
  • Out of Band (OOB)

Additional information about LE Secure Connections and the models can be found here:

Our Bluetooth 4.0 smartBASIC modules (BT900 /BL600 /BL620) support Simple Secure Pairing and Encryption 
Additional information about Simple Secure Pairing can be found here:
We recommend reviewing the Pairing, Bonding and Security Manager functions in the BL6xx/BT900 smartBASIC Extensions User Guides. The full security of the Bluetooth/Bluetooth Low Energy connection will depend largely on how the smartBASIC application is written, and what the input/output capabilities are of the devices that are connecting. If either device will not have any input/output capabilities then pairing will have to default to Just Works, which is the least secure pairing method. However there are additional layers of security that can be added to increase protection from hacking when the Just Works pairing model is used.

With Bluetooth Low Energy, to further secure the connection, it is recommended that the metadata for the characteristic attributes are configured for Encryption with man-in-the-middle protection for characteristic value access. This will prevent anyone from accessing data on the module without proper encryption keys. (See BleAttrMetadataEx in the BL6xx/BT900 smartBASIC Extensions User Guides.) Additionally, when using Just Works pairing, or any time additional security is required, we recommend adding a challenge/response question to the application layer, with a timer, which expects the connecting device to respond to the challenge question in a specified period of time after a connection has occurred. If the correct response is not received within that time period the application would force a disconnection. Finally, whisper mode pairing can be used during the pairing process as an additional layer of security. This is accomplished by reducing the Tx power while pairing using BleTxPwrWhilePairing as per the BL6xx/BT900 smartBASIC Extensions User Guide, which will reduce the radius which a hacker would need to breach in order to capture or spoof the encryption procedure.

What are the production programming options for the BL65x modules when using smartBASIC?

For production programming we recommend the following options:

  1. FLASH cloning: Instructions for FLASH cloning can be found in the firmware Zip files, which can be downloaded from the BL65x Product Page. There are two README files contained in the "Firmware" folder of the files, as well as the utilities required to create the cloned image. The first option, ____READ_ME_TO_CLONE_FILESYSTEM___, captures only the flash file and data system and does not include the firmware. The second option,  READ_ME_TO CLONE FIRMWARE_&_APP__, clones the flash file and data system as well as the firmware. When possible, we recommend cloning the firmware as well as the flash and data systems.
  2. MultideviceLoader, which is a command-line application for Windows, Linux and Mac that can be used to XCompile an application (Windows only) and download it to multiple Laird devices at the same time and provides options for: renaming the file, running it after download and other functions. This is a companion application for UwTerminalX and is mostly suited to production/end-stage testing purposes. Command line arguments are available in the Wiki on the GitHub repository.

Note: UwFlashx and Uwflash_embed are for firmware upgrades, and cannot be used to program smartBASIC applications.

Can I use Windows to scan for my BLE Peripheral and Connect to it?

Laird does not provide a Windows utility for scanning and connecting to BLE devices. We are also not aware of any existing third party apps to do this either. Android and iOS are the best options for scanning for and connecting to BLE radios. 

How can I connect a Bluetooth Low Energy Device to a PC?

Bluetooth Low Energy uses Services as opposed to the set of standardized profiles that exists for Classic Bluetooth. While some Bluetooth Low Energy services have been standardized by the Bluetooth SIG, the development of custom services is allowed to meet custom application requirements.
Because Bluetooth Low Energy uses a completely different protocol than Classic Bluetooth and supports custom services, Bluetooth Low Energy devices cannot connect to a computer through the typical Bluetooth configuration of a computer. Therefore, connecting to a PC requires writing and running a Bluetooth Low Energy Central Role/Client application to collect the data sent from the Bluetooth Low Energy peripheral modules. Application development for PCs and Mobile devices is outside the scope of our support. Alternatively, a BL654 USB dongle could be used as a BLE Central Role device, to collect the BLE data and pass it to the PC over a COM Port. However, you would still need an application to view and process the data received over that COM Port.
We generally recommend customers who are new to Bluetooth Low Energy obtain a copy of Getting Started with Bluetooth Low Energy to help them understand the Bluetooth Low Energy protocol and the GATT table. There are also many resources available online which explain this. 

When Bluetooth Low Energy was first introduced and we launched our BL6xx product line (predecessors to the BL65x series) we produced the BL600 and BL620 smartBASIC Application Walkthrough document, which provides an overview of how Bluetooth Low Energy works and how a GATT table is constructed.