Upgrading LoRaWAN Application by adding LoRa Peer-to-Peer Link onto Microchip ATSAMR34 Xplained Pro Kit

Home Labs Stories Upgrading LoRaWAN Application by adding LoRa Peer-to-Peer Link onto Microchip ATSAMR34 Xplained Pro Kit

by Gregory Demont

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Posted on Dec. 11, 2018

#Node #Microchip #ATSAMR34 #SAMR34 #SiP #P2P

Intermediate

2 Hours

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Introduction

LoRa is a radio Physical layer (PHY) modulation technology focusing on battery-powered endpoints over long-range radio connectivity. It offers long air propagation distance, low power consumption, high receiving sensitivity, low data rates, robust spectrum spreading, and secured encryption transmission.

LoRaWAN is a Media Access Layer (MAC) protocol specification defined and maintained by the LoRa Alliance on top of the LoRa radio physical layer. It characterizes the device-to-infrastructure (LoRa®) physical layer parameters & (LoRaWAN™) protocol and so provides seamless interoperability between manufacturers. It is designed to scale from a single gateway infrastructure up to large global networks with many devices. A LoRaWAN network architecture is deployed in a star-of-stars topology in which gateways relay messages between end-devices and a central network server.

A peer-to-peer communication using LoRa technology allows a direct communication and long-distance between 2 devices. This is particularly useful in restrained environment where global LoraWAN infrastructure is not needed or simply not available. Or in a hybrid infrastructure, where some devices will be set to only communicate thru peer to peer (low latency, low Opex) while others will also be connected to LoraWAN infrastructure (gateway).

There are many applications for peer to peer Lora connectivity taking full advantage of the Long-range and low power characteristics of Lora technology. It includes garage door-opener (GDO), smart home or industrial smart sensors, alarm systems, commissioning of LoraWAN network.

Last but not least, the high-link budget offers a 30-dB improvement over FSK to reject co-channel interference and delivers power consumption seven times lower to minimize operational cost. This makes LoRa a viable option for increasing efficiency across a very wide range of applications.

Different peer-to-peer examples illustrate the various application of the LoRa technology embedded insider the ATSAMR34.

More information on this product could also be found here :
https://www.microchip.com/design-centers/wireless-connectivity/low-power-wide-area-networks/lora-technology/sam-r34-r35

Software Installation

Here the list of software used in this tutorial.

Atmel Studio 7.0

Download and install Atmel Studio 7.0 IDE.
https://www.microchip.com/mplab/avr-support/atmel-studio-7
Open Atmel Studio 7.0 IDE.
Then, you need Advanced Software Framework (ASFv3) installed as an extension to Atmel Studio.
From the menu, go to Tools -> Extensions and Updates ... and install Advanced Software Framework (>= 3.44.0 release).
Once the installation is complete, you must restart Atmel Studio.

Note: ASFv3 is an MCU software library providing a large collection of embedded software for AVR® and SAM flash MCUs and Wireless devices. ASFv3 is configured by the ASF Wizard in Atmel Studio 7.0 (installed as an extension to Studio). ASFv3 is also available as a standalone (.zip) with the same content as Studio extension (https://www.microchip.com/mplab/avr-support/advanced-software-framework).

Important:
Until the next Atmel Studio IDE release, you have to manually install the Device Part Pack for developing with SAMR34/R35 on Atmel Studio 7.0 IDE.
(all products released in between IDE releases of Atmel Studio should be manually added by user to develop applications).

Go to Tools -> Device Pack Manager
Check for Updates
Search for SAMR34 and click install
Repeat the same for SAMR35
Restart Atmel Studio 7.0 IDE

Tera Term

Download and install the serial terminal program from: https://osdn.net/projects/ttssh2/releases/

MiWi Simple P2P on top of LoRa Radio

MiWi™ Development Environment (MiWi™ DE) is developed by Microchip to support a wide range of wireless applications. The backbone of MiWi™ DE is MiMAC and MiApp interfaces, which link the support of multiple RF transceivers as well as wireless communication protocols together as a well-defined simple but robust Microchip proprietary wireless development environment.

MiWi™ DE is defined in three layers: application layer, protocol layer and RF transceiver layer. The three layers are linked together by MiMAC and MiApp interfaces. Application layer uses MiApp interfaces to talk to the protocol layer.

On top of the LoRa Radio transceiver embedded in the ATSAMR34 device, the MiWi™ stack can enable a Simple Peer-to-Peer communication with a very small foot-print.

The Long-range capable radio can offer a perfect solution for a department store HVAC or alarm application or a large smart home application.

The simple example application code focuses on the simplicity of the MiWi™ DE protocol stack application programming interfaces. It provides a clean and straightforward wireless communication between two devices with less than 30 lines of effective C code to run the stack in application layer for both devices. In this application, following features of MiWi™ DE protocol stack has been demonstrated:

• Establish connection automatically between two devices

• Broadcast a packet

• Unicast a packet

• Apply security to the transmitted packet

Note: In this application, the TAL (Transceiver Abstraction Layer) from the Microchip LoRaWAN Stack is re-used. The TAL uses the radio drivers and provides access to the LoRa Transceiver embedded in the ATSAMR34.

To get details on MiWi P2P Wireless Protocol, you can refer to the following link: http://ww1.microchip.com/downloads/en/AppNotes/00001204C.pdf

The sample application will be available soon.