P-NUCLEO-LRWAN3

UM2073 User manual STM32 LoRaWAN® Expansion Package for STM32Cube Introduction This user manual describes the I-CUBE-LRWAN LoRaWAN® Expansion Package implementation on the STM32L0 Series, STM32L1 Series, and STM32L4 Series microcontrollers. This document also explains how to interface with the LoRaWAN® to manage the LoRa® wireless link. LoRa® is a type of wireless telecommunication network designed to allow long-range communications at a very low bit-rate and enabling long-life battery-operated sensors. LoRaWAN® defines the communication and security protocol that ensures interoperability with the LoRa® network. The LoRaWAN® Expansion Package is compliant with the LoRa Alliance® specification protocol named LoRaWAN®. The I-CUBE-LRWAN main features are the following: • Integration-ready application • • • • • Easy add-on of the low-power LoRa® solution Extremely-low CPU load No latency requirements Small STM32 memory footprint Low-power timing services provided The I-CUBE-LRWAN Expansion Package is based on the STM32Cube HAL drivers (Refer to LoRa standard overview). This user manual provides customer examples on NUCLEO-L053R8, NUCLEO-L073RZ, NUCLEO-L152RE, and NUCLEOL476RG using Semtech expansion boards SX1276MB1MAS, SX1276MB1LAS, SX1272MB2DAS, SX1262DVK1DAS, SX1262DVK1CAS, and SX1262DVK1BAS. This document targets the following tools: • P-NUCLEO-LRWAN1, STM32 Nucleo pack for LoRa® technology (Legacy only) • P-NUCLEO-LRWAN2, STM32 Nucleo starter pack (USI®) for LoRa® technology • P-NUCLEO-LRWAN3, STM32 Nucleo starter pack (RisingHF) for LoRa® technology • B-L072Z-LRWAN1, STM32 Discovery kit embedding the CMWX1ZZABZ-091 LoRa® module from Murata • I-NUCLEO-LRWAN1, LoRa® expansion board for STM32 Nucleo, based on the WM-SG-SM-42 LPWAN module (USI®) available in P-NUCLEO-LRWAN2 LRWAN-NS1, expansion board featuring the RisingHF modem RHF0M003 available in P-NUCLEO-LRWAN3 • UM2073 - Rev 12 - September 2021 For further information contact your local STMicroelectronics sales office. www.st.com UM2073 General information 1 General information The I-CUBE-LRWAN Expansion Package runs on STM32 32‑bit microcontrollers based on the Arm® Cortex®-M processor. Note: 1.1 Arm is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere. Terms and definitions Table 1 presents the definitions of the acronyms that are relevant for a better contextual understanding of this document. Table 1. List of acronyms Acronym ABP Activation by personalization App Application API Application programming interface BSP Board support package FSM Finite‑state machine FUOTA Firmware update over the air HAL Hardware abstraction layer IoT Internet of things LoRa® LoRaWAN® LPWAN MAC MCPS MIB Long-range radio technology LoRa® wide-area network Low-power wide-area network Media access control MAC common part sublayer MAC information base MLME MAC sublayer management entity MPDU MAC protocol data unit OTAA Over-the-air activation PLME Physical sublayer management entity PPDU Physical protocol data unit SAP SBSFU UM2073 - Rev 12 Definition Service access point Secure Boot and Secure Firmware Update page 2/52 UM2073 Overview of available documents and references 1.2 Overview of available documents and references Table 2 lists the complementary references for using I-CUBE-LRWAN. Table 2. References ID Description [1] LoRa Alliance specification protocol named LoRaWAN version V1.0.3 July 2018 final release [2] Low-Rate Wireless Personal Area Networks (LRWPANs) IEEE Std 802.15.4TM, 2011 [3] LoRaWAN® Regional Parameters v1.0.3revA, July 2018 release [4] LoRa Alliance Fragmented Data Block Transport over LoRaWAN Specification v1.0.0 September 2018 [TS‑004] [5] LoRa Alliance Remote Multicast Setup over LoRaWAN Specification v1.0.0 September 2018 [TS‑005] [6] LoRa Alliance Application layer clock synchronization over LoRaWAN Specification v1.0.0 September 2018 [TS‑003] [7] Application note Integration guide for the X-CUBE-SBSFU STM32Cube Expansion Package (AN5056) [8] Application note I-CUBE-LRWAN embedding FUOTA, application implementation (AN5411) [9] Application note Examples of AT commands on I-CUBE-LRWAN (AN4967) [10] Application note How to build a LoRa® application with STM32CubeWL (AN5406) [11] User manual Getting started with the P-NUCLEO-LRWAN2 and P-NUCLEO-LRWAN3 starter packs (UM2587) [12] User manual STM32 Nucleo-64 boards (MB1136) (UM1724) [13] User manual STM32WL Nucleo-64 board (MB1389) (UM2592) [14] WM-SG-SM-42 AT Command Reference Manual located under USI_I-NUCLEO-LRWAN1(1) [15] RHF-PS01709 LoRaWAN Class ABC AT-Command Specification available from RiSiNGHF home page(1) 1. This URL belongs to a third party. It is active at document publication, however, STMicroelectronics shall not be liable for any change, move, or inactivation of the URL or the referenced material. UM2073 - Rev 12 page 3/52 UM2073 LoRa® standard overview 2 LoRa® standard overview 2.1 Overview This section provides a general overview of the LoRa® and LoRaWAN® recommendations, particularly focusing on the LoRa® end device that is the core subject of this user manual. LoRa® is a type of wireless telecommunication network designed to allow long-range communication at a very low bit rate and enabling long-life battery-operated sensors. LoRaWAN® defines the communication and security protocol ensuring interoperability with the LoRa® network. The LoRaWAN® Expansion Package is compliant with the LoRa Alliance® specification protocol named LoRaWAN®. Table 3 shows the LoRaWAN® class usage definition. Refer to Section 2.2.2 for further details on these classes. Table 3. LoRaWAN® classes intended usage Class name A - All B - Beacon C - Continuous Intended usage • Battery-powered sensors or actuators with no latency constraint • Most energy-efficient communication class • Must be supported by all devices • Battery-powered actuators • Energy-efficient communication class for latency controlled downlink • Based on slotted communication synchronized with a network beacon • Main powered actuators • Devices that can afford to listen continuously • No latency for downlink communication Note: While the physical layer of LoRa® is proprietary, the rest of the protocol stack (LoRaWAN®) is kept open and its development is carried out by the LoRa Alliance®. 2.2 Network architecture The LoRaWAN® network is structured in a star of stars topology, where the end devices are connected via a single LoRaWAN® link to one gateway as shown in Figure 1. Figure 1. Network diagram LoRaWAN® end device Gateway Network server Application server Pet tracking Smoke alarm Water meter Trash container Vending machine Gas monitoring UM2073 - Rev 12 page 4/52 UM2073 Network architecture 2.2.1 End-device architecture The end device is composed of an RF transceiver (also known as radio) and a host STM32 MCU. The RF transceiver is composed of a modem and an RF up-converter. The MCU implements the radio driver, the LoRaWAN® stack and optionally the sensor drivers. 2.2.2 End-device classes The LoRaWAN® has several different classes of end-point devices, addressing the different needs reflected in the wide range of applications. Bi-directional Class-A end devices (all devices) • • • • Class-A operation is the lowest power end-device system. Each end-device uplink transmission is followed by two short downlinks receive windows. Downlink communication from the server shortly after the end‑device has sent an uplink transmission (Refer to Figure 2). Transmission slot is based on the own communication needs of the end device (ALOHA-type protocol). Figure 2. Tx/Rx time diagram (Class-A) Tx Rx1 Rx2 RxDelay1 RxDelay2 Bi-directional end‑devices with scheduled receive slots - Class-B - (beacon) • • • • Mid power consumption Class-B devices open extra receive windows at scheduled times (Refer to Figure 3). For the end device to open the receive window at the scheduled time, the end device receives a timesynchronized beacon from the gateway. As Class‑A has priority, the device replaces the periodic ping slots with an uplink (Tx) sequence followed by Rx1 or Rx2 received windows when required by the device. Figure 3. Tx/Rx time diagram (Class-B) BCN PNG PNG Tx Rx1 Rx2 BCN RxDelay1 Period Ping RxDelay2 Beacon Period UM2073 - Rev 12 page 5/52 UM2073 Network architecture Bi-directional Class-C end devices with maximal receive slots (continuous) • • Large power consumption Class-C end devices have nearly continuously open receive windows, only closed when transmitting (Refer to Figure 4). Figure 4. Tx/Rx time diagram (Class-C) Tx Rx1 Rx2 RxC On-air transmit time RxC RxDelay1 RxDelay2 2.2.3 RxC Extends RxC until next uplink End-device activation (joining) Over-the-air activation (OTAA) The OTAA is a joining procedure for the LoRaWAN® end device to participate in a LoRaWAN® network. Both the LoRaWAN® end device and the application server share the same secret key known as AppKey. During a joining procedure, the LoRaWAN® end device and the application server exchange inputs to generate two session keys: • • A network session key (NwkSKey) for MAC commands encryption An application session key (AppSKey) for application data encryption Activation by personalization (ABP) In the case of ABP, the NwkSkey and AppSkey are already stored in the LoRaWAN® end device that sends the data directly to the LoRaWAN® network. UM2073 - Rev 12 page 6/52 UM2073 Network architecture 2.2.4 Regional spectrum allocation The LoRaWAN® specification varies slightly from region to region. The European, North American, and Asian regions have different spectrum allocations and regulatory requirements (Refer to Table 4 for more details). Table 4. LoRaWAN® regional spectrum allocation Region Supported Band (MHz) Duty cycle (%) Output power (dBm)(1) EU Y 868