P-NUCLEO-LRWAN3: Transmitting Sensor Value Between Two Boards via LoRa

[adarsh860]

Hi everyone,

I’m new to LoRa and STM32 development, and I’m trying to set up communication between two devices using the P-NUCLEO-LRWAN3 kit. Here's my setup:

Transmitter Node:
- NUCLEO-L073RZ
- LRWAN_NS1 sensor expansion board (433/470 MHz)

Receiver Gateway:
- NUCLEO-F746ZG
- LRWAN_GS_LF1 gateway expansion board (433/470 MHz)

I’ve successfully read sensor values like temperature from the transmitter node. Now, I want to send a simple value like "10" from the transmitter to the receiver using LoRa.

I’m using Zephyr RTOS and following the LoRa sample examples, but I’m not sure how to:
1. Transmit a custom value (like a string or integer)
2. Receive and print/display that value on the receiver side

Additionally, I’ve received two pairs of antennas with the kit – one pair for 434 MHz and one for 480 MHz. I'm not sure which one I should use for proper transmission. Any guidance on that would also be helpful.

Could anyone guide me or share a minimal working example for this?

Thanks in advance!

[Andrew Neil]

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@adarsh860 wrote:

I’m new to LoRa 

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Do you understand the difference between LoRa and LoRaWAN?

• LoRa is purely an RF modulation technique
• LoRaWAN is a complete network, using LoRa for is RF links.

https://www.thethingsnetwork.org/docs/lorawan/what-is-lorawan/

https://www.korewireless.com/blog/lora-vs-lorawan-what-is-the-difference/#:~:text=LoRaWAN%20is%20the%20network%20protocol,is%20communicated%20across%20the%20network.

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@adarsh860 wrote:

and STM32 !

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Do you have experience with any other microcontroller(s)?

If not, it would be wise to first start with some basic projects to gain familiarity with the product and the tools, etc.

https://community.st.com/t5/stm32-mcus-products/for-better-learning-stm32-programming-and-debugging/m-p/719485/highlight/true#M260696

Links to learning resources:

https://community.st.com/t5/stm32-mcus-products/for-better-learning-stm32-programming-and-debugging/m-p/719468/highlight/true#M260690

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@adarsh860 wrote:

I want to send a simple value like "10" from the transmitter to the receiver using LoRa.

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The purpose of a Gateway is connect devices to a LoRaWAN network.

If all you want is to send simple data between two nodes, you don't need LoRaWAN.

Therefore, you don't need a Gateway.

For just a simple LoRa link between two nodes, see the Ping-Pong example.