https://github.com/fescron/efm32-rn2483-masterbuoy
Happy Gecko (SLSTK3400A) interfacing with LoRaWAN using dbprint
https://github.com/fescron/efm32-rn2483-masterbuoy
cayenne dbprint dramco emf32 emlib geckoboard happygecko iot kuleuven lora lorawan microcontroller putty rn2483 simplicity-studio slstk3400a thethingsnetwork uart wireless-communication
Last synced: about 1 month ago
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Happy Gecko (SLSTK3400A) interfacing with LoRaWAN using dbprint
- Host: GitHub
- URL: https://github.com/fescron/efm32-rn2483-masterbuoy
- Owner: Fescron
- Created: 2018-11-21T16:08:41.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2019-09-28T15:51:22.000Z (over 5 years ago)
- Last Synced: 2023-11-27T19:54:46.531Z (over 1 year ago)
- Topics: cayenne, dbprint, dramco, emf32, emlib, geckoboard, happygecko, iot, kuleuven, lora, lorawan, microcontroller, putty, rn2483, simplicity-studio, slstk3400a, thethingsnetwork, uart, wireless-communication
- Language: C
- Homepage:
- Size: 430 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# EFM32-RN2483-Masterbuoy
The code is based on the [DRAMCO EFM32-RN2483-LoRa-Node example](https://github.com/DRAMCO/EFM32-RN2483-LoRa-Node) with functions from [dbprint](https://github.com/Fescron/dbprint) aswell and is designed for use on the [EMF32 Happy Ghecko board](https://www.silabs.com/products/development-tools/mcu/32-bit/efm32-happy-gecko-starter-kit).
Added code is marked with ```/* BEGIN ADDED CODE ********/``` and ```/* END ADDED CODE ********/```. Code was added in the following files when starting from the DRAMCO example:
- ```src/my_lora_device.h``` (```LORAWAN_DEVICE_EUI```, ```LORAWAN_APPLICATION_EUI``` and ```LORAWAN_APPLICATION_KEY``` hidden)
- ```lora/lpp.c```
- ```lora/lpp.h```
- ```system/leuart.c```
Added the following file (declaration of "public" variables):
- ```src/main.h```
**Other useful links:**
- [The Things Network - Applications (Register LoRaWAN device)](https://console.thethingsnetwork.org/applications/)
- [Cayenne Dashboard](https://cayenne.mydevices.com/cayenne/dashboard/start)
------
## 1 - Documentation
This code receives messages over UART (**115200 baudrate**) using interrupts, parses the characters back to numbers, repacks it into a LPP (Cayenne Low Power Payload) packet and sends the data to the cloud using a LoRaWAN network.
### 1.1 - Code flow
The following flowchart mostly describes the added functionality. For the sake of completeness all of the logic states (INIT, ...) are added but not really further discussed. Most of the code was added in the state **SEND** and **SLEEP**.
#### 1.1.1 - Extra notes on the flowchart
- **(\*1):** If there was a line received using interrupts on UART *AND* there is at least one of the three buffers free, copy the received data to one of those buffers.
- **(\*2):** Check if **one (of three)** or more buffers are filled *AND* at least one of the two data fields (```data0``` and ```data1```) are free.
- **(\*3):** Parse the data out of a used buffer into a free data field.
#### 1.1.2 - Processes (= states of the logic) on the flowchart
- **INIT:**
- Initialize system & chip (clocks, ...).
- Initialize delay function.
- Initialize interrupts (IRQ).
- Initialize LED functions to give feedback when there is an error.
- Initialize buttons and their interrupt functionality.
- Initialize power management.
- Initialize ADC for reading the battery voltage.
- Initialize I²C for sensor readout.
- Initialize UART using dbprint functionality for:
- Printing debug messages.
- Getting input using interrupts.
- Parsing characters to values.
- **JOIN:**
- Initialize LoRaWAN communications with *Over The Air Activation* (OTAA).
- **MEASURE:**
- Read battery voltage.
- Read relative humidity.
- Read temperature.
- **NOTE:** The sensor readouts are not really used since we have a limited amount of bytes we can send to the cloud.
- **SEND:**
- See flowchart.
- **SLEEP:**
- See flowchart.
------
### 1.2 - Structure of messages
#### 1.2.1 - UART
The Received UART lines need to have the following structure (the data is in **decimal notation**):
| Data | Bouy ID | RSSI | VBAT |
|:-----------:|:-------:|:-------:|:-------:|
| **Length** | 3 chars | 2 chars | 3 chars |
| **Example** | 008 | 66 | 325 |
The example data corresponds with:
- **Bouy ID** = 8
- **RSSI** = (-)66
- **VBAT** = 3,25 V
- **NOTE:** The VBAT data gets send to "the cloud" with a **bouy-ID-offset of "1"**!!
#### 1.2.2 - LPP
After parsing the UART characters back to numbers, the retransmitted [Cayenne Low Power Payload](https://github.com/myDevicesIoT/cayenne-docs/blob/master/docs/LORA.md) packet has the following structure (the data is in **hexadecimal notation**, *each column represents one byte*):
| LPP terminology | Data channel | Data type | Byte 0 | Data channel | Data type | Byte 0 | Byte 1 |
|:---------------:|:------------:|:-------------:|:------:|:------------:|:------------:|:------:|:------:|
| **Data** | Bouy ID | Digital Input | | Bouy ID + 1 | Analog Input | | |
| **Example** | 08 | 00 | 42 | 09 | 02 | 01 | 45 |
As noted above, the **RSSI value** is *disguised as* an **analog input** while the **VBAT data** is *disguised as* a **digital input**.
The example data corresponds with:
- **Bouy ID** = 0x08 = 8d
- **RSSI** = 0x42 = 66d
- **VBAT** = 0x0145 = 325d
- **NOTE:** The VBAT data gets send to "the cloud" with a **bouy-ID-offset of "1"**!!