This repository contains the sourcecode for a prototype called "LoRaKastl". It has been developed by 5 students at UAS Technikum Wien during the course "InnovationLab 1".
The purpose of the project was to learn about LoRa/LoRaWAN and IoT programming in general. The final idea was to build a physical mailbox that notifies you on your phone, whenever it is being opened. It was meant to be a POC to overcome the inital hurdles while working with our tech stack.
The mailbox itself has the following components:
- a LoRaWAN compatible microcontroller with an antenna attached to it that sends a message into the "TheThingsNetwork" once the cover is being opened, and otherwise idles in low power sleep.
- a Reed Switch Sensor to recognize the box cover being opened
- a battery, to power the mc
- a 3d-printed case the mc fits in
Once the data has arrived at TheThingsNetwork, it needs to be forwarded. To receive the message at our phone, we did the following:
- TheThingsNetwork has a built in MQTT broker which we used to subscribe to our device's uplink messages via a
- Node-RED instance - e.g. running at a remote server or a local Docker container.
- the Node-RED instance parses the message and forwards it to the Telegram Bot API
- in the end, the message arrives in the Telegram App.
Microcontroller -> LoRaWAN -> TTN -> NodeRed (MQTT) -> Telegram Bot
The following things are needed in order to set up the whole message delivery pipeline:
- Heltec CubeCell AB01 https://heltec.org/project/htcc-ab01/
- MicroUSB Data Cable
- Reed Switch x1
- Jumper Cables x2
- Arduino Battery
- Some Magnet
Make sure you have
- an Account at https://www.thethingsnetwork.org/
- PlatformIO as VSCode extension (or any other compatible IDE)
- Docker installed on the system your Node-RED backend should run on
- Log into your TTN account
- Create a new application and give an appropriate name
- Register a new end device
- Select "HelTec AutoMation" as End device brand
- "HTCC-AB01(Class A)" as Model
- Hardware Version "Unknown"
- Firmware Ver "1.0"
- Profile (Region) "EU_863_870" - the right model + image should pop up
- Select the recommended frequency plan (SF9)
- For the JoinEUI, enter all zeros
- Generate a DevEUI
- Generate an AppKey
- Hit "Register end device"
- leave the browser tab open
$ git clone https://github.com/LoRaWahnsinn/LoRaKastl.git- open it in VSCode via
code LoRaKastl/ - PlatformIO should recognize the configuration automatically
- goto
src/main.cppand fill in the Variables with the values of your device registered at ttn- those are needed for the over-the-air-activation (OTAA)
static uint8_t devEui[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
static uint8_t appEui[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
static uint8_t appKey[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};- Plug your CubeCell into a USB-Port
- Press the "Home" icon located at the bottom bar, to get to the PIO Home
- Click left on "Devices" and check, if your device appears under the "Serial" tab
- If its not present, (under Windows) check for optional driver updates and/or reboot your system
- Linux users should be able to solve the problem themselves.
- Hit "Build" (the checkmark) in the bottom bar and hope it turns out green.
- If so, hit "Upload" right next to it.
- As soon as the process finishes successfully, the LED on your CubeCell should begin to blink, indicating the LoRa module being active.
- open the PIO Serial Monitor, the socket and wait until
JOINEDis being printed. - open your ttn device browser tab and switch to "Live Data"
- If you see a join request, the connection was successful
- attach or solder a Jumper Cable to GND and GPIO1 each
- Bring the tho cables together and watch the Serial Monitor, it prints "SENT" if successful
- Check the Live Data at TTN if your Message arrived (Uplink data)
- It should contain the string "Check mail" in Hexadecimal format
- connect each cable to the reed switch
- one side has two contacts, we need the default CLOSED one
- bring a magnet near the sensor, then release it and check, if a message has been sent
- if a message is sent regardless of the magnet being present, try the other contact
$ docker build -t lorakastl node-red/
$ docker run --detach -p 1880:1880 --name lorakastl lorakastl- at TTN select left Integrations -> MQTT
- generate a new API Key and save it, it is only viewable once.
- note the username
- goto http://localhost:1880
- doubleclick the node "TTN Endpoint"
- Hit the pencil icon to configure the MQTT server
- Change to tab "Security" and enter your username and API Key
- Hit Update
- The topic you need to subscribe to has the following format:
v3/<your-username-here>/devices/eui-<your-eui-here>/up- Enter your username and id of your device - hit Done, then hit Deploy in the upper right corner
- doubleclick the Telegram node
- Hit the pencil icon to configure the bot
- enter your Token you got from BotFather
- if you need help, consider reading: https://flows.nodered.org/node/node-red-contrib-telegrambot
- Hit Update, hit done.
- Finally, hit deploy
Done! Now you should (fingers crossed) get a message to your Telegram Bot, shortly after you remove the magnet from to your reed switch.