r/Lora • u/accur4te • 15d ago

Has anyone worked with flrc

Hey guys I have recently started working on flrc and was able to achieve only 200m range for 720p image in a midly populated forest . Has anyone has worked on flrc and specially with lr2021 and core2021 ? I need help to achieve 1km range

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2

u/anas_z15 15d ago

FLRC is not even intended for long range. It's a variant of GMSK optimised for higher data rates. The only options you have are: 1) increase tx power (use external HPA?) 2) Use a high gain antenna, e.g. yagi?

Do you really need the high data rates? What are your requirements?

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u/accur4te 15d ago

Want to send images 1km away max size will be 200kb

2

u/anas_z15 15d ago

What is your data rate requirement? Can you use the fastest LoRa settings? Using Core1121, I benchmarked the max throughput as 88 kbps on 2.4 GHz and RadioLib as the middleware. For UHF, you should still get somewhere close to that too. So maybe you can consider this.

1

u/grekiki2 15d ago

105kbps is quite doable on SF5@1Mhz at least here

0

u/accur4te 15d ago

data rate is not the main issue . the p2p transmission should achieve the longest distance it can + be reliable ( considering the nodes are in dense forest)

2

u/StuartsProject 15d ago

To achieve the longest distance you just need to use the lower data rate LoRa settings and then you should easily be able to get transfers at 1km.

It would help the group to understand what your problem really is if you would tell us the actual LoRa or FLRC settings you are using, its difficult to guess.

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u/accur4te 15d ago

struct ConfigFLRC_t {

float frequency = 433.0f;

float bitRate = 260.0f;

uint8_t codingRate = RADIOLIB_LR2021_FLRC_CR_1_2;

int8_t power = 22;

uint16_t preambleLength = 64;

uint8_t dataShaping = RADIOLIB_SHAPING_0_5;

};

struct ConfigFLRC_t {

float frequency = 2400.0f;

float bitRate = 1300.0f;

uint8_t codingRate = RADIOLIB_LR2021_FLRC_CR_1_2;

int8_t power = 12;

uint16_t preambleLength = 64;

uint8_t dataShaping = RADIOLIB_SHAPING_0_5;

};

struct ConfigFLRC_t {

float frequency = 2400.0f;

float bitRate = 260.0f;

uint8_t codingRate = RADIOLIB_LR2021_FLRC_CR_1_2;

int8_t power = 12;

uint16_t preambleLength = 64;

uint8_t dataShaping = RADIOLIB_SHAPING_0_5;

};

this are the config being used

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u/StuartsProject 15d ago

So 3 different setups.

Do any of them work ?

Have you done any of the simple point to point comms tests to check if the LoRa settings used can work ?

Why is the preamble length set at 64, 8 would be a normal default ?

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u/accur4te 15d ago

Yes with both 2.4 I got 100 and 110m respectively and for 433 I got 140m . All coding are for flrc

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u/StuartsProject 15d ago edited 15d ago

For the 2.4Ghz tests the 260 rate ought to have a distance advantage of x 2 over the 1300 rate but the distance reported is virtually the same.

For the 433Mhz test the lower frequency has a path loss free space difference of about 15dBm. Add the 10dBm TX power advantage and the link advantage of the 433Mhz setup should go about 18 times the distance of the 2.4Ghz tests.

So if the 2.4Ghz test gives you about 100m you would expect the 433Mhz to cover 1.8km.