when sending only the preamble is received not the payload

[dje8269]

Hi all,

I'm currently trying to get an LLCC68 chip working to create a remote control.
I'm using LLCC68MB2xAS development boards for my test associated whith STM32 µC.

I've configured the first board as a transmitter and the second as a receiver.
On the first board, I transmit a frame when a button is pressed.
The second board is in rx single mode. Really simple !

I activate the Rx IRQ on RxDone on the receiver and by quickly pressing the transmitter button, thus sending numerous frames from time to time, I manage to receive the message. But it's about 1 time out of 30.

If I activate the IRQ on reception of the preamble, the IRQ is triggered every time.

I've followed tutorials and examples, but I don't understand where I'm going wrong.

Here's my Rx and Tx configuration. I'm using the semtech library.

Find in the attchment my code for ini and send and receive .

Thank you

rx-tx.txt

[jgromes]

I'm using the semtech library.

So why are asking this question in a repository of a different library?

by quickly pressing the transmitter button, thus sending numerous frames

You will need to handle at least debouncing the button, waiting for transmission completion before sending another packet, handling errors etc. But your code shows none of this.

FWIW I don't think there's an issue in Semtech code. This library also uses RX done interrupt and there have never been any issues with it. The problem is almost certainly in the part of the code you have not shown us. Not that I want to see it, it has nothing to do with this project.

[dje8269]

So why are asking this question in a repository of a different library?
Sorry if I posted the message in the wrong place, I'm not familiar with github

I'm sure the semtech code works perfectly.
But I don't know where my mistake is in initializing or using the receive and receive mode or transmitter mode
That's why I'm looking for help comparing my initialization with someone else's.

Even if you press the button once to send only one frame, the receiver receives it incorrectly. Only the preamble is detected.

Can you share your initialsiation code working good?

[StevenCellist]

Well, as we do not use the Semtech library, we do not have the code for you to compare with. I assume you got your Semtech code from somewhere that is either their own GitHub, or a place that shows the link to their GitHub - otherwise you can use Google to find their GitHub repository yourself. That would be the place for this question. We specifically do not use Semtech code here :)

[jgromes]

@dje8269 feel free to examine how we initialize LLCC68 (aka SX126x) modules here:

RadioLib/src/modules/LLCC68/LLCC68.cpp

Line 9 in a88ec8d

int16_t LLCC68::begin(float freq, float bw, uint8_t sf, uint8_t cr, uint8_t syncWord, int8_t pwr, uint16_t preambleLength, float tcxoVoltage, bool useRegulatorLDO) {

[dje8269]

Ok, I understand ! I'm on the wrong category.
Sorry for disturb and tnak you for your share.
But maybe you can still help me, because it's mainly about using the LLCC68 module and not necessarily about the programming itself.

I'm confused, because on the receiver, when I activate the IRQ for receiving the preamble "LLCC68_IRQ_PREAMBLE_DETECTED", the IRQ fires fine with each send, it's perfect.
When I set the IRQ to timeout, it also works.

But when I set the IRQ to one of these choices: LLCC68_IRQ_SYNC_WORD_VALID | LLCC68_IRQ_HEADER_VALID | LLCC68_IRQ_HEADER_ERROR | LLCC68_IRQ_RX_DONE |
LLCC68_IRQ_CRC_ERROR

It doesn't fire! Or very rarely after numerous attempts.
What value do you use for syncword?