Lora Simple RX/TX WL55 problem

[alirezadh2]

I used two Nucleo_WL55 boards and python code for simple lora communication and it does not working ( time out):

Send:

from umachine import Pin, SPI
import time
import pyb
import lora
import micropython

micropython.alloc_emergency_exception_buf(256)

def get_sync_modem():
from lora import WL55SubGhzModem
lora_cfg = { 'freq_khz': 868000 }
return WL55SubGhzModem(lora_cfg=lora_cfg)

def main_task():
counter=0
modem = get_sync_modem()
modem.calibrate()
while True:
print("Sending...")
modem.send(f"Hello from AEMICS #{counter}".encode(),tx_at_ms=None)
print("Sent!")
pyb.LED(1).toggle()

if name == "main":
main_task()

Receive:

from umachine import Pin, SPI
import time
import pyb
import lora
import micropython

micropython.alloc_emergency_exception_buf(256)

def get_sync_modem():

from lora import WL55SubGhzModem
	lora_cfg = { 'freq_khz': 868000 }
return WL55SubGhzModem(lora_cfg)  

def main_task():

modem = get_sync_modem()
modem.calibrate()
modem.rx_crc_error = True
while True:
	print("Receiving...")
	rx = modem.recv(timeout_ms=10000, rx_length=0xFF, rx_packet=None)
   		if rx:
     		print(f"Received: {repr(rx)}")
   	        else:
		print("Receive timeout!")
        pyb.LED(1).toggle()

if name == "main":
main_task()

I got this errors:
Receiving...
_radio_isr
RX flags 0x200
Receive timeout!

[davefes]

Try to re-edit your post using code tags. Start with 3 back-ticks py, line feed, your code, line feed and finish with 3 back ticks. Have you had the Simple RX/TX example working? Your sender method doesn't have any delays in it.

[davefes]

I am interested that you do a modem.calibrate() I did not read about that requirement.

Are you running the sender method on one unit and the receiver method on the 2nd NUCLEO?

[davefes]

Also, be aware of the limitation on file size upload on the NUCLEO_WL55.
https://github.com/orgs/micropython/discussions/13160
Small files <1KB will probably work.

[alirezadh2]

Thanks for reply, yeah I used one unit for sending and one for receiving, it doesn't receive any thing

[alirezadh2]

I remove modem.calibrate() and also add delay on sending still not working:

#Send:

from machine import Pin, SPI
import time
import pyb
import lora
import micropython

micropython.alloc_emergency_exception_buf(256)

def get_sync_modem():
	from lora import WL55SubGhzModem
    	lora_cfg = { 'freq_khz': 868000 }
	return WL55SubGhzModem(lora_cfg=lora_cfg)    

def main_task():
	counter=0
	modem = get_sync_modem()
	while True:
       	        print("Sending...")
                modem.send(f"Hello from AEMICS #{counter}".encode(),tx_at_ms=None)
		time.sleep_ms(1000)
                print("Sent!")
	        pyb.LED(1).toggle()
               

if __name__ == "__main__":
	main_task() 



#Receive:


from machine import Pin, SPI
import time
import pyb
import lora
import micropython

micropython.alloc_emergency_exception_buf(256)

def get_sync_modem():

	from lora import WL55SubGhzModem
    	lora_cfg = { 'freq_khz': 868000 }
	return WL55SubGhzModem(lora_cfg)  

def main_task():

	modem = get_sync_modem()
	modem.rx_crc_error = True
	while True:
		print("Receiving...")
		rx = modem.recv(timeout_ms=5000, rx_length=0xFF, rx_packet=None)
       		if rx:
         		print(f"Received: {repr(rx)}")
       	        else:
			print("Receive timeout!")
	        pyb.LED(1).toggle()
               

if __name__ == "__main__":
	main_task() 

[davefes]

The Simple RX/TX example I was following uses:

modem = get_modem()

On 2nd thought maybe it is smart enough to work out which modem you have installed.

[davefes]

Also, this might help:
https://github.com/orgs/micropython/discussions/13180
especially doing mpremote mip install lora-sync ... it was just updated.

[alirezadh2]

I am using sync modem, your setup is working with Async modem?

[alirezadh2]

your setup is Nucelo_WL55?

[davefes]

I have only just started this "journey" ... still using sync modem. Some day I may have to do a Async project.

Most of my current work on LoRa is using the WeACT BlackPill using this repro:
https://github.com/nspsck/STM32F411CEU6_BlackPill_Micropython/tree/main

I did spend a few days trying to get micropython/lora to work on a E77-400M22S, which uses a STM32WL5x part. I could not debug my application as that part and evidently the NUCLEO_WL55 will not allow you to upload files bigger than about 1KB.

[alirezadh2]

I am also trying to figure out more details in micropython files about lora libraries.