112 lines
3.3 KiB
Markdown
112 lines
3.3 KiB
Markdown
# imaginaerraum LoRa Workshop
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This workshop assumes you are familiar with the basics of MicroPython (see [apo's MicroPython Workshop][micropython-workshop] for an introduction).
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[micropython-workshop]: https://imaginaerraum.de/git/apo/micropython-workshop
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## Hardware
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We use the [Wemos® TTGO LORA32 868/915Mhz board][wemos].
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[wemos]: https://www.banggood.com/2Pcs-LILYGO-TTGO-LORA32-915Mhz-ESP32-LoRa-OLED-0_96-Inch-Blue-Display-p-1239769.html
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## Software
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We make use of the two MicroPython libraries [uPyLora by lemariva][lemariva] and [uLoRaWAN by mallagant][mallagant]. uPyLora is a driver for the SX1276 LoRa module which is connected to the ESP32.
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uLoRaWAN is a library which creates LoRaWAN packages, which you can then transfer via LoRa to send data to [TheThingsNetwork][ttn].
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I added a wrapper class [LoRaTransceiver](micropython/lora_transceiver.py) which makes them a bit easier to use.
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[lemariva]: https://github.com/lemariva/uPyLora
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[mallagant]: https://github.com/mallagant/uLoRaWAN
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[ttn]: https://www.thethingsnetwork.org/
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## Setup
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The files you will need are all located in the `micropython/` subfolder. To get started, you can either upload the file
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* `lora_transceiver.py`
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and the folders
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* `uPyLora/`
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* `uLoRaWAN/`
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* `uPySensors/`
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to the ESP, or just flash [this image](micropython/esp32-image/image.bin).
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Here are some examples how to use the LoRa module:
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__1. LoRa sending:__
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```
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from lora_transceiver import LoRaTransceiver
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from uPySensors.ssd1306_i2c import Display
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d = Display()
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# create transceiver
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lora = LoRaTransceiver(display=d)
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# send data
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lora.send_string('imaginaerraum')
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```
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__2. LoRa receiving:__
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```
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from lora_transceiver import LoRaTransceiver
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from uPySensors.ssd1306_i2c import Display
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d = Display()
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# create transceiver
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lora = LoRaTransceiver(display=d)
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# start receiving data
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#lora.recv()
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```
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__3. LoRaWAN sending:__
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```
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from lora_transceiver import LoRaTransceiver
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from uPySensors.ssd1306_i2c import Display
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import uLoRaWAN
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from uLoRaWAN.MHDR import MHDR
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d = Display()
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# create transceiver for LoRaWAN frequency (channel 0 = 868.1 Mhz)
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lora = LoRaTransceiver(frequency=868.1E6, syncword=0x34, display=d)
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# change the spreading factor
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lora.setSpreadingFactor(9)
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# TODO: set address and keys for LoRaWAN
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devAddr = [0x00, 0x00, 0x00, 0x00]
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nwkSKey = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
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appSKey = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
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devAddr_hex = " ".join(["%02X" % (x,) for x in devAddr])
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nwkSKey_hex = " ".join(["%02X" % (x,) for x in nwkSKey])
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appSKey_hex = " ".join(["%02X" % (x,) for x in appSKey])
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print("devAddr: ", devAddr_hex)
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print("nwkSKey: ", nwkSKey_hex)
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print("appSKey: ", appSKey_hex)
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# lorawan object for conversion of data in LoRaWAN message format
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lorawan = uLoRaWAN.new(nwkSKey, appSKey)
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def send_lorawan(message, frame_cnt=0):
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lorawan.create(MHDR.UNCONF_DATA_UP, {'devaddr': devAddr, 'fcnt': frame_cnt, 'data': list(map(ord, message)) })
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payload = lorawan.to_raw()
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lora.send(payload)
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print("lorawan message sent")
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send_lorawan("Hello world!")
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```
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(you can also find these in the `examples/` subdirectory)
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For more information, have a look at the documentation of the [LoRaTransceiver](micropython/lora_transceiver.py) class.
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