TALLINN UNIVERSITY OF TECHNOLOGY School of Information Technologies IE70LT Muhammad Faizan Aziz Khan IVEM165530 LORA BASED SMART AGRICULTURE SYSTEM Master's thesis Supervisor: Dr. Paul Annus PhD Senior Research Scientist Co-Supervisor: Dr. Tauseef Ahmed PhD Lecturer Tallinn 2018 TALLINNA TEHNIKAÜLIKOOL Infotehnoloogia teaduskond IE70LT Muhammad Faizan Aziz Khan IVEM165530 LORA SÜSTEEMIL PÕHINEV PÕLLUMAJANDUSSÜSTEEM Magistritöö Juhendaja: Dr. Paul Annus PhD Vanemteadur Kaasjuhataja: Dr. Tauseef Ahmed PhD Lektor Tallinn 2018 Author’s declaration of originality I hereby certify that I am the sole author of this thesis. All the used materials, references to the literature and the work of others have been referred to. This thesis has not been presented for examination anywhere else. Author: Muhammad Faizan Aziz Khan 13.05.2017 3 Abstract Advancements in low power and low-cost computation and communication technology have brought a revolution in remote sensing and monitoring applications. The Internet of Things paradigm promises an ecosystem of connected devices spread across a vast variety of application domains. This thesis deals with the practical aspects of engineering such a system of connected devices for monitoring agricultural systems. Currently, there are many competing standards and technologies trying to take a hold of IoT, especially the area of remote sensing and communication technology. LoRa is one of these technologies gaining popularity in the application of Wireless Sensor Networks (WSNs). The ability of LoRa to establish communication links over long distances with relatively simple nodes, minimal infrastructure, low power requirements and utilization of license-free ISM bands give it a considerable edge of its competitors. Although a lot of research work has been done about the efficacy of LoRa for low power wireless sensor networks, there are still gaps in the literature about the practical aspects of design and implementation of such systems. This work focuses on problem of implementing a localized sensor network for a smart agriculture system using LoRa as the main communication technology. A system for monitoring temperature, pressure and humidity is implemented using low cost solutions available in the market and results are presented. This thesis is written in English and is 49 pages long, including 5 chapters, 36 figures and 1 table. 4 Annotatsioon LoRa süsteemil põhinev Põllumajandussüsteem Madala võimsusega ja maksumusega arvutustehnika ja kommunikatsioonitehnoloogia progress on teinud kaugseire- ja seirerakenduste valdkonnas revolutsiooni. Asjade Interneti paradigma kirjeldab ühendatud seadmete ökosüsteemi, mis on levinud paljude rakenduste domeenide hulgas. Käesolev tees kirjeldab inseneritöö praktilisi aspekte nagu põllumajandussüsteemide seireks mõeldud ühendatud seadmete süsteem. Tänapäeval on palju konkureerivaid standardeid ja tehnoloogiad, mis tegutsevad Asjade Interneti valdkonnas, eriti kaugseire ja kommunikatsioonitehnoloogia valdkonnas. LoRa on üks nendest tehnoloogiatest, mis saab veelgi populaarsemaks Traadita Andurite Võrgustiku rakendamise valdkonnas. LoRa on võimeline looma sideühendusi pikkade vahemaade üle suhteliselt minimaalse infrastruktuuriga ja madalate energiatarbenõuetega, ja lisaks, litsentsivaba ISM-ide kasutamine annab sellele suurepärast konkurentsivõimet. Vaatamata sellele, et on juba tehtud palju uuringuid LoRa efektiivsuse väikese võimsusega traadita andurite võrgustiku seoses, kirjanduses on ikka veel puudusi selliste süsteemide disainimise ja rakendamise praktiliste aspektide kohta. See töö keskendub traadita andurite võrgustiku väikeste põllumajandussüsteemile rakendamisele, kasutades LoRa kui peamist kommunikatsioonitehnoloogiat. Süsteem on mõeldud temperatuuri, rõhu ja niiskuse seireks ja seda rakendatakse kasutades turul saadaval olevaid madala maksumusega lahendusi ning tulemused on esitatud. Lõputöö on kirjutatud inglise keeles ning sisaldab teksti 49 leheküljel, 5 peatükki, 36 joonist, 1 tabelit. 5 List of abbreviations and terms BLE Bluetooth Low Energy IoT Internet of Things LoRa Long Range Radio Protocol LPWSN Low Power Wireless Sensor Network LPWAN Low Power Wide Area Network WSN Wireless Sensor Node/Wireless Sensor Node Wi-Fi Wireless Fidelity RTOS Real Time Operating System DVFS Dynamic Voltage and Frequency Scaling HTML Hypertext Mark-up Language TOA Time on Air SNR Signal to Noise Ratio DSSS Direct Sequence Spread Spectrum RF Radio Frequency OSI Open System Interconnection ISM Industrial Scientific Medical MCU Microcontroller Unit GPS Global Positioning System CSS Chirp Spread Spectrum FSK Frequency Shift Key UART Universal Asynchronous Receiver Transmitter I2C Inter Integrated Circuit GPIO General purpose Input Output FIFO FIRST-in First-out 6 Table of Contents Author’s declaration of originality ................................................................................... 3 Abstract ............................................................................................................................. 4 Annotatsioon LoRa süsteemil põhinev Põllumajandussüsteem ....................................... 5 List of abbreviations and terms ........................................................................................ 6 Table of Contents ............................................................................................................. 7 List of figures ................................................................................................................. 10 List of tables ................................................................................................................... 12 1 Chapter 1 ................................................................................................................ 13 1.1 Introduction ...................................................................................................... 13 1.2 WSN Background ............................................................................................ 14 1.2.1 Brief History ............................................................................................. 15 1.2.2 Sensor Nodes ............................................................................................ 16 1.2.3 Networking Structure and Topology ........................................................ 17 1.2.4 Routing Protocols ..................................................................................... 19 1.2.5 Application Areas ..................................................................................... 20 1.3 Motivation ........................................................................................................ 20 1.4 Problem statement ............................................................................................ 21 1.5 Objectives and Goals ....................................................................................... 22 1.6 Significance of work ........................................................................................ 22 1.7 Report structure and work frame ..................................................................... 22 2 Chapter 2 ................................................................................................................ 24 2.1 System Overview ............................................................................................. 24 2.1.1 Endpoint ................................................................................................... 24 2.1.2 Gateway .................................................................................................... 24 2.1.3 Web Interface ........................................................................................... 25 2.2 LoRa Introduction ............................................................................................ 25 2.3 LoRa Network Architecture ............................................................................. 25 2.4 LoRa Modulation Scheme ............................................................................... 26 2.4.1 Shannon-Hartley Theorem ....................................................................... 27 7 2.4.2 Spread-Spectrum Basics ........................................................................... 27 2.4.3 Chirp Spread-Spectrum (CSS).................................................................. 30 2.4.4 LoRa Chirp Spread-Spectrum .................................................................. 32 2.4.5 Salient Features of LoRa Modulation ....................................................... 34 2.4.6 LoRa Modules .......................................................................................... 35 2.4.7 LoRa PHY Packet ..................................................................................... 36 2.4.8 LoRa Transmission Time ......................................................................... 37 2.5 LoRa Networking Protocol .............................................................................. 39 2.5.1 LoRaWAN ................................................................................................ 39 2.5.2 Libelium LoRa Protocol ........................................................................... 40 2.5.3 LoRa Limitations ...................................................................................... 43 3 Chapter 3 ................................................................................................................ 44 3.1 Hardware: LoRa Endpoint Design ................................................................... 44 3.1.1 MCU Platform .......................................................................................... 44 3.1.2 Performance .............................................................................................. 44 3.1.3 Development Environment ....................................................................... 45 3.1.4 Memory .................................................................................................... 45 3.1.5 Peripherals ................................................................................................ 45 3.1.6 Cost ........................................................................................................... 46 3.1.7 Debugging ................................................................................................ 46 3.2 MSP430F5529LP Launchpad .......................................................................... 46 3.3 Sensor Platform ................................................................................................ 47 3.4 Lora Platform ................................................................................................... 48 3.5 Hardware: LoRa Gateway Design ................................................................... 49 3.6 Software Resources .......................................................................................... 50 3.6.1 Code Composure Studio ........................................................................... 50 3.6.2 Raspbian Linux Distribution .................................................................... 51 3.6.3 WAZIUP IoT Framework ........................................................................ 51 3.6.4 Tera Term ................................................................................................. 51 4 Chapter 4 ................................................................................................................ 52 4.1 HopeRF LoRa Library ..................................................................................... 52 4.2 BME280 Sensor Library .................................................................................. 57 4.3 Web Interface ................................................................................................... 59 4.4 Gateway State Machine ................................................................................... 59 8 4.5 Endpoint State Machine ................................................................................... 60 5 Chapter 5 ................................................................................................................ 61 5.1 Results and discussion ..................................................................................... 61 5.2 Conclusion ....................................................................................................... 62 References ...................................................................................................................... 63 Appendix 1 – Source Code ............................................................................................. 66 1. LoRa.h .............................................................................................................. 66 2. LoRa.c .............................................................................................................. 70 3. BME280.h ........................................................................................................ 88 4. BME280.c ........................................................................................................ 91 9 List of figures Figure 1. Gartner Hype Cycle 2017 [5]. ......................................................................... 14 Figure 2. Wireless Sensor Network Connected to Cloud. .............................................. 15 Figure 3. Typical WSN Node. ........................................................................................ 16 Figure 4. Single Hop Star. .............................................................................................. 18 Figure 5. Multi-hop Mesh Topology. ............................................................................. 19 Figure 6. Smart Agriculture System [23]. ...................................................................... 21 Figure 7. System Overview. ........................................................................................... 24 Figure 8. Network Topology. ......................................................................................... 26 Figure 9. TOA for Various Combinations of LoRa Settings [29]. ................................. 26 Figure 10. Spread Spectrum Modulation Using Coding Sequence. ............................... 28 Figure 11. Spread Spectrum Demodulation Scheme. ..................................................... 29 Figure 12. Up-Chirp in Time Domain. ........................................................................... 30 Figure 13. Down-Chirp in Time Domain. ...................................................................... 30 Figure 14. Chirp pulse and resulting pulse after compression [33]. ............................... 31 Figure 15. CSS Block Diagram [33]. ............................................................................. 31 Figure 16. Samtech SX127x Series Block Diagram [34]. .............................................. 35 Figure 17. LoRa PHY Packet Structure [35] . ................................................................ 36 Figure 18. OSI Model. .................................................................................................... 39 Figure 19. The LoRaWAN Stack [36]............................................................................ 40 Figure 20. LoRa Channels, 868-870 MHz [37] . ............................................................ 41 Figure 21. LoRa Channels, 902-982 MHz [37]. ............................................................. 42 Figure 22. LoRa Network Modes [37]. .......................................................................... 42 Figure 23. LoRa Protocol Packet Structure. ................................................................... 42 Figure 24. Packet Type Field. ......................................................................................... 43 Figure 25. LoRa Endpoint. ............................................................................................. 44 Figure 26. MSP430F5529 Launchpad. ........................................................................... 46 Figure 27. Bosch BME280 Sensor Platform. ................................................................. 48 Figure 28. Draguino V1.4. .............................................................................................. 48 Figure 29. LoRa Gateway. .............................................................................................. 49 10