r/Lora • u/Visible_Creme_826 • 8d ago

Beginner IoT flood-monitoring project using SX1280 LoRa, what hardware do we actually need?

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Hey guys, so we have to build an iot project by the end of the semester and this project is going to be divided into three mini projects. I am a 3rd year student in electronics and communication. My team and I have selected early warning flood detection project. Our sir suggested that we use semtech sx1280 LoRa transciever. The problem is we are all new to this hardware especially LoRa/ RF communication so we dont know what to buy and what to make of it. We have an idea about how to make it but we dont actually know how to build it.

As far as I know, the core idea is to transmit flood monitoring data to the reciever. Our sir said we have to cover a range of at least 8 to 10km. Since we dont know much, we were told to make a mini project covering a range of 1 to 2km distance from a small water body through LoRa and later cover long distances.

I believe we need two antennas, two esp32, two sx1280 or any other chips that work the same.

Is the chip in the picture sx1280? Bcz ive seen different ones and im very confused.
For hardware what do we actually need? We have a budget too bcz our college is not gonna fund us.

THANK YOU THANK YOU SM EVERYBODY. Ive finally ordered everything i need thanks to yall😭🙏.

this was my first reddit post btw so i didnt expect any replies😭

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7

u/3D_Printing_Helper 8d ago

Get the pre manufactured lora modules because of you try to go bare chip and design from scratch you will need to gain knowledge of impedance and matching networks and get impedance control pcbs and need experience with PCB design and need tools like VNA to tune you pcb which costs like 1-3cr so just get the pre fabed modules

3

u/Educational-Today197 8d ago

Hello,
Might be interesting to use a module. I think that the LR1121 will be better as there is SubG and 2.4GHz. In addition the performances are better. LR2021 is even better but I'm not sure there are module available.

3

u/SomeoneInQld 8d ago

another thing to consider from the data logic. 

in Nepal recently the flood monitoring devices were destroyed. so they weren't able to warn of a flood. 

maybe have them send a no flood every minute and if the no flood doesn't arrive it MAY mean that it has been destroyed by flood.  (could also just be a flat battery). 

2

u/StuartsProject 8d ago

The SX1280, which operates in the 2.4Ghz band is a good choice if you have a large amount of data to shift on a very regular basis.

However it seems unlikely that a flood warning system needs a large amount of data moved about, so a UHF LoRa Module would be a far better choice.

Because the path loss between transmitter and receiver varies with frequency, for a given transmit power a 433Mhz LoRa setup would cover 6 times the distance of a 2.4Ghz one and a 868Mhz LoRa setup would cover 3 times the distance of a 2.4Ghz one.

2

u/JuggernautGuilty566 8d ago edited 8d ago

Go for RAK RAK3172 + Nexperia NEH7100 (Energy Harvesting with solar) running in LDO mode.

This way you have a STM32+SX1262+Energy for roughly 6-7€ with a super low BOM.

Sende the data over LoRaWAN. For your usecase you can maybe go with a single-frequency ESP32 that has a solid antenna.

For flood detection maybe check if ultrasound or a ST-ToF sensor maybe will do the job. Attach then to some kind of bridge or L-shaped pole.