I have a big problem, as I cannot find a way to send data from my Lopy to my computer via serial port.
From the beggining: I have to lopys that communicate through LORA to each other sending short messages if they are within the range to connect to each other (one asking if in range and receiving the answer, second one listening and answering if it is in range). What I want to do now, is to be able to see the answer "in range" on my computer, when lopy is connected to it via serial port. I understand that first I need to modify my code on lopy so it is sending the message to the PC and later in py write a code to read it but I do not know how to do that and where to start....

any help will be much appreciated!!!!!

Monika

from machine import UART
uart = UART(1, 115200)
...
uart.write("value = %d\n" % value)

value is here an arbitrary name for something to send. I use here \n at the end of the write to send the data nicely in lines, so you could see it in the PC well ordered, even with a terminal software
b) This is an example of a little python3 script, which receives the data from the USB serial and puts it optionally into a file. It requires pyserial.py to be installed beforehand, with pip3 install pyserial

import sys
import serial
from time import sleep


def main():
    if len(sys.argv) > 1:
        port = sys.argv[1]
        if len(sys.argv) > 2:
            filename = sys.argv[2]
            try:
                f = open(filename, "w")
            except:
                print("Could not open file:", filename)
                return
        else:
            f = None
# open file
        try:
            ser = serial.Serial(port, 115200)
            sleep(3)
            ser.reset_input_buffer()
        except Exception as err:
            print("Could not connect: {!r}".format(err))
            return
        print("Data connection at:", port)
        while True:
            try:
                line = ser.readline().decode().rstrip("\r\n")
                if line != '': # Still alive?
                    print(line)
                    if f is not None:
                        f.write(line + "\r\n")
                else: # EOF
                    break
            except Exception as err:
                print("{!r}".format(err))
                break
            except KeyboardInterrupt:
                print("Interrupted!")
                break
        if f is not None:
            f.close()
    else:
        print("Usage: usbrecv port [filename]")

if __name__ == "__main__":
    main()

from network import LoRa
import socket
import time
from machine import UART

uart = UART(1, 115200)

lora = LoRa(mode=LoRa.LORA, frequency=863000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)
while True:
s.send('In range?')
my_message = s.recv(64)

if len(my_message) > 0:
    uart.write("my_message\n")
else:
    uart.write("out of range\n")

time.sleep(10)

it is connected via serial to PC and when i connect via Putty I get nothing

the code on second lopy is this one:

from network import LoRa
import socket
import time

lora = LoRa(mode=LoRa.LORA, frequency=863000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)

while True:
if s.recv(64) == b'In range?':
s.send('You are within LORA range!')

time.sleep(10)

everything works perfect when i operate with Atom....

Where do i make a mistake??

Maybe i am missing part of the code where i define data bits and stop bits so they are defined exactly like the ones in putty?

PS i have updated the firmware on my lopys and running my code from main.py on both. in atom everything is ok

from network import LoRa
import socket
import time
from machine import UART
uart = UART(0, 115200)
lora = LoRa(mode=LoRa.LORA, frequency=863000000)
s = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
s.setblocking(False)
while True:
s.send('In range?')
my_message = s.recv(64)
if len(my_message) > 0:
uart.write(my_message)
else:
uart.write("out of range")
time.sleep(10)

I do not want to run a code from putty but to run it from main and only see messages sent between two lopys in putty, the final step will be to receive through spyder, but as a first step i wanted to see if they are sent by lopy to a computer correctly.

seems that there is some error in main.py line 6 OSError: the requested operation failed, thats what i get when restarting the board:

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun 8 2016 00:22:57

rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff9010,len:12
ho 0 tail 12 room 4
load:0x3fff9020,len:388
load:0x40078000,len:11584
load:0x4009fb00,len:848
entry 0x4009fc9c
Traceback (most recent call last):
File "main.py", line 6, in <module>
OSError: the requested operation failed
MicroPython v1.8.6-796-g489fafa0 on 2017-10-15; LoPy with ESP32
Type "help()" for more information.

and the line 6 in main.py is an uart line:
uart = UART(0, 115200)

from network import LoRa
import socket
import time
import os
os.dupterm(None)
...