Finally, my problem is Solved : With pygate, no need to register the device EUI, just create one from scratch ! (and edit config.json accordingly) as the doc says

Just guessing, but you should probably set the same spreading factor on the receiver also?

@Eric73 Thanks for the info

In case anybody else has this problem. In our case it was either a defective L01 OEM module or a manufacturing defect with the PCB. We built a second unit and the LoRa worked fine in that L01 module. It did not hang or crash, and the LoRa pings worked fine over several minutes of testing.

@researcher Nice chart, what hardware do you use on the GNURadio Side ? Software libraries ?

@jcaron @robert-hh so sorry for late, because these 2 days im quite busy I just updated both lopy to the latest version after i update i have problem connect to Adafruit, which is OSError:-1 I combine my code with this tutorials link

@robert-hh Thanks! You saved my day again.

@monersss Raw LoRa is a best effort medium with absolutely no acknowledgements or retransmissions. If you want to be sure that data has been received, you will need to implement such a strategy. That involves adding frame counters (not absolutely needed in the most basic case, but it’s usually a good idea), sending back ACKs when you have received data, and resending data if you don’t get the ACK. Note that if your target scenario is not point to point but multiple senders to one receiver, LoRAWAN may be a simpler option as this can be handled by LoRaWAN. However be aware of the limitations on the band.

@monersss Can you post a sample of the file stored on the SD card? I programmed the first lopy to constantly send hello, and this was my result: Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello ...

I have the same problem after upgrading to release='1.16.0.b1', version='v1.8.6-849-055728a on 2018-02-13' now I have to do a wlan init (and wlan deinit) to get the mac address firmware bug? tnx André

@bucknall Had a couple of hours on it and have all 5 units working. I'm not sure I fully understand the issue, but this is what I noticed: I have a wifi router connected to my laptop, that I'm using as a separate AP for the Lopy. If I disconnect the ethernet from the Laptop, this may remove the problem. So, I've wondering if there is RF EMC interference in the cables between the router/laptop/lopy. Also if I then reboot the Lopy the problem disappears.