exploring_lora
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exploring_lora [2018/09/27 17:00] – [2. Theoretical Study] samer | exploring_lora [2018/09/29 13:02] – samer | ||
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As defined by Semtech, [[http:// | As defined by Semtech, [[http:// | ||
- | In this lab, you will implement a prototype of LoRa communication between two wireless | + | In this lab, you will implement a prototype of LoRa communication between two wireless |
<WRAP center round help 100%> | <WRAP center round help 100%> | ||
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Download the following software on your PC: | Download the following software on your PC: | ||
- | * RadioHead: The Packet Radio library for embedded microprocessors can be downloaded from [[http://www.airspayce.com/mikem/ | + | * RadioHead: The Packet Radio library for embedded microprocessors can be downloaded from [[https://github.com/samerlahoud/ |
* Arduino IDE: Specific OS versions can be downloaded from [[https:// | * Arduino IDE: Specific OS versions can be downloaded from [[https:// | ||
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Note well the location of the library folder on your computer. In the following, you will be required to modify source files located in this folder. | Note well the location of the library folder on your computer. In the following, you will be required to modify source files located in this folder. | ||
</ | </ | ||
- | |||
==== -. Installation ==== | ==== -. Installation ==== | ||
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* What is the relation between processing gain and spreading factor in LoRa modulation? Explain. | * What is the relation between processing gain and spreading factor in LoRa modulation? Explain. | ||
* How does the spreading factor impact the coverage of a LoRa transmitter? | * How does the spreading factor impact the coverage of a LoRa transmitter? | ||
- | * For each of the three possible configurations of your LoRa module, what is the transmission bit rate? Explain your computation. | + | * For each of the three possible configurations of your LoRa device, what is the transmission bit rate? Explain your computation. |
* Compute the receiver sensitivity, | * Compute the receiver sensitivity, | ||
* Compare the computed sensitivity to that provided by the {{ : | * Compare the computed sensitivity to that provided by the {{ : | ||
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==== -. Modifying the Radio Parameters ==== | ==== -. Modifying the Radio Parameters ==== | ||
- | Start by setting | + | Download |
+ | |||
+ | Take a look at the source code in '' | ||
+ | |||
+ | * Central frequency (freq) | ||
+ | * Spreading Factor (SF) | ||
+ | * Bandwidth (Bw) | ||
+ | * Coding Rate (CR) | ||
+ | * Transmit power (Pow) | ||
+ | |||
+ | <code c++> | ||
+ | rf95.setFrequency(frequency); | ||
+ | // Setup Power,dBm | ||
+ | rf95.setTxPower(13); | ||
+ | |||
+ | // Setup Spreading Factor (6 ~ 12) | ||
+ | rf95.setSpreadingFactor(7); | ||
+ | |||
+ | // Setup BandWidth, option: 7800, | ||
+ | //Lower BandWidth for longer distance. | ||
+ | rf95.setSignalBandwidth(125000); | ||
+ | |||
+ | // Setup Coding Rate: | ||
+ | rf95.setCodingRate4(5); | ||
+ | </ | ||
+ | |||
+ | In order to reduce collisions, configure | ||
^ Group Number | ^ Group Number | ||
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| | | | ||
- | For this, open the '' | ||
- | |||
- | <file cpp RH_RF95.cpp> | ||
- | setFrequency(86X.Y); | ||
- | </ | ||
- | |||
- | The typical configuration for LoRa modules consists of 125 kHz sub-channels, | ||
- | |||
- | * Bw125Cr45Sf128 | ||
- | * Bw125Cr48Sf4096 | ||
- | * Bw31_25Cr48Sf512 | ||
- | |||
- | Radio configuration is applied in '' | ||
- | <file cpp RH_RF95.cpp> | ||
- | setModemConfig(Bw125Cr45Sf128); | ||
- | </ | ||
==== -. Running Basic Sketches ==== | ==== -. Running Basic Sketches ==== | ||
- | Download the {{ : | + | Now you can compile and upload |
[{{ : | [{{ : | ||
[{{ : | [{{ : | ||
- | |||
- | In the remainder of this lab, you will conduct measurements to validate the obtained theoretical receiver sensitivity. | ||
===== -. Performance Evaluation ===== | ===== -. Performance Evaluation ===== | ||
In the following, you will design and implement a set of scenarios that enable to evaluate the performance of the LoRa modulation. As you will deal with scientific assessment, you are required to use scientific tools to show the results. You have the choice between [[http:// | In the following, you will design and implement a set of scenarios that enable to evaluate the performance of the LoRa modulation. As you will deal with scientific assessment, you are required to use scientific tools to show the results. You have the choice between [[http:// | ||
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- | In this section, you will measure the coverage of LoRa modules | + | In this section, you will measure the coverage of LoRa devices |
<code c++> | <code c++> |
exploring_lora.txt · Last modified: 2021/10/20 12:52 by samer