exploring_lora
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exploring_lora [2018/10/06 13:52] – [3.1. Modifying the Radio Parameters] samer | exploring_lora [2018/10/22 16:53] – [5. Coverage Challenge] samer | ||
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Unzip the RadioHead library and copy it to your sketchbook library folder as detailed in [[https:// | Unzip the RadioHead library and copy it to your sketchbook library folder as detailed in [[https:// | ||
+ | |||
+ | <WRAP center round tip 75%> | ||
+ | Make sure to restart your computer after the installation of Arduino IDE and run the software as administrator. | ||
+ | </ | ||
+ | |||
+ | |||
==== -. Installation ==== | ==== -. Installation ==== | ||
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- | For Arduino Mega 2560, additional drivers for Microsoft Windows can be installed from [[http:// | + | For Arduino Mega 2560, additional drivers for Microsoft Windows |
+ | For Arduino Duemilanove, | ||
+ | [[https:// | ||
</ | </ | ||
===== -. Theoretical Study ===== | ===== -. Theoretical Study ===== | ||
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- | * What is the relation between processing gain and spreading factor in LoRa modulation? | + | * What is the relation between processing gain and spreading factor in LoRa modulation? |
* How does the spreading factor impact the coverage of a LoRa transmitter? | * How does the spreading factor impact the coverage of a LoRa transmitter? | ||
* What is the transmission bit rate for each of the following configurations of your LoRa device? Explain your computation. | * What is the transmission bit rate for each of the following configurations of your LoRa device? Explain your computation. | ||
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==== -. Running Basic Sketches ==== | ==== -. Running Basic Sketches ==== | ||
- | Now you can compile and upload the client and server sketches on the two arduino devices, respectively. On the serial interfaces, you should obtain similar results as in Fig. 2 and Fig. 3. The client sends periodically a short message | + | Now you can compile and upload the client and server sketches on the two arduino devices, respectively. On the serial interfaces, you should obtain similar results as in Fig. 2 and Fig. 3. The client sends periodically a short packet |
[{{ : | [{{ : | ||
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==== -. Time on Air ==== | ==== -. Time on Air ==== | ||
- | In this section, you will measure the Time on Air (ToA) that is given by the time necessary to transmit a message | + | In this section, you will measure the Time on Air (ToA) that is given by the time necessary to transmit a packet |
- | Start by implementing a function on the client that measures the time necessary for sending a message. For example, you can use the [[https:// | + | Start by implementing a function on the client that measures the time necessary for sending a packet. You can have recourse to the [[https:// |
+ | |||
+ | For example, the scenario for assessing the impact of the spreading factor on the ToA consists of sending 100 packets for three different spreading factors //e.g.,// 7, 9, and 10, and drawing the average ToA or the distribution in a boxplot for comparing the results. | ||
+ | |||
+ | As for the theoretical computation of the ToA, you can refer to the the following documents : | ||
+ | |||
+ | * The Semtech [[http:// | ||
+ | * An explanatory video: https:// | ||
+ | * Various calculation tools available online: https:// | ||
+ | |||
+ | Note that all messages sent and received by the [[https:// | ||
+ | |||
+ | * 8 symbol PREAMBLE | ||
+ | * Explicit header with header CRC (handled internally by the radio) | ||
+ | * 4 octets HEADER: (TO, FROM, ID, FLAGS) | ||
+ | * 0 to 251 octets DATA | ||
+ | * CRC (handled internally by the radio) | ||
<WRAP center round help 100%> | <WRAP center round help 100%> | ||
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The setting for this experiment is unique: | The setting for this experiment is unique: | ||
- | |||
* Only one server is required in the classroom. This server should compute the ratio of successfully delivered packets or PDR. | * Only one server is required in the classroom. This server should compute the ratio of successfully delivered packets or PDR. | ||
* All groups are required to use the same frequency, spreading factor, and coding rate. | * All groups are required to use the same frequency, spreading factor, and coding rate. | ||
- | * On each client, packets will be generated following a Poisson process with the same average arrival rate for all groups. | + | * The average |
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* Direct transmission between the two devices is only considered. | * Direct transmission between the two devices is only considered. | ||
- | * 3D distance is computed between devices. | + | * 3D distance is computed between devices. You can get the elevation from this [[ http:// |
- | * PDR must be higher than 10% as computed for 100 packets. | + | * PDR must be higher than 10% as computed for 100 packets. |
+ | * Supporting live video and screen capture should be used to authenticate the record. | ||
+ | |||
+ | You can use the [[https:// | ||
<WRAP center round help 100%> | <WRAP center round help 100%> | ||
- | * Compute the Fresnel zone for your transmission. | + | * Compute the Fresnel zone for your transmission |
- | * Provide the expression of the link budget and compute the received power using two different | + | * Provide the expression of the link budget and compute the received power using two different |
- | * Compare the received power obtained experimentally with the theoretical | + | * Compare the received power obtained experimentally with the results |
- | * Write an article | + | * Prepare a short presentation |
+ | </ | ||
+ | |||
+ | <WRAP center round important 75%> | ||
+ | This challenge and the corresponding grading is considered as a part of the final project. | ||
</ | </ | ||
===== -. Grading ===== | ===== -. Grading ===== | ||
- | | ^ Exemplary | + | | |
- | ^ Answer | + | ^ Techniques for Engineering Practice |
- | ^ Design experiments | + | ^ Skills for Engineering Practice |
- | ^ Analyse results | + | ^ Engineering tools | Students showed advanced ability |
+ | ^ Problem solving | ||
+ | ^ Results and analysis | ||
+ | ^ Motivation, initiative, and creativity | ||
+ | ^ Written communication skills | ||
+ | ^ Scientific referencing |
exploring_lora.txt · Last modified: 2021/10/20 12:52 by samer