WebREPL not working with main.py-started app (fixed)

[yolk]

Hi!

I used WebREPL to interactively play around with my board without any issues. I start WebREPL within boot.py.
After starting another program (after WebREPL in boot.py) however, WebREPL does not properly work any more. When trying to log in, I'm queried for the password, and after that, I don't get any response any more (not even a newline after entering the password).
The other program I launch apparently continues execution without issues. It basically consists of a main loop in the form of " while True: measure something; send to server; delay 60s".
My guess is that the incoming WebREPL connection preempts (?) this main loop, and the connection is handled up to the point that the initial welcome message and the password prompt is sent to the client. Further IO on the WebREPL connection however is not handled as the main loop is not preempted any more. Does this make sense?
How can this be avoided? That is, how can I execute some sort of main loop while remaining responsive to WebREPL? Is there some function I could call within the main loop that triggers the handling of pending connections?


Thanks in advance!

Thanks,

yolk

[pfalcon]

No, WebREPL just doesn't work how you apparently think it does. ESP8266 is not a gigahertz/gigabyte machine where each opens a new independent session, like telnet/SSH connection to Unix boxes does. ESP8266 is very resource-constrained device, and there's only one session running. You can access that session either via UART or WebREPL. That's it. So, when you connect via WebREPL, you get to your running application. If it doesn't accept any input and doesn't produce any output, it appears to be "hung" for you. Ctrl+C it to get back to the Python interactive prompt if that's what you want.

[yolk]

Hi!

Thanks for the quick reply!

[quote="pfalcon"]No, WebREPL just doesn't work how you apparently think it does. ESP8266 is not a gigahertz/gigabyte machine where each opens a new independent session, like telnet/SSH connection to Unix boxes does. ESP8266 is very resource-constrained device, and there's only [i]one session[/i] running. You can access that session either via UART or WebREPL. That's it. So, when you connect via WebREPL, you get to your running application. [/quote]
Yes, that's roughly what I assumed.

[quote="pfalcon"] If it doesn't accept any input and doesn't produce any output, it appears to be "hung" for you. Ctrl+C it to get back to the Python interactive prompt if that's what you want.[/quote]
Ctrl+C doesn't have any effect, the application continues executing. Also, I don't get the debug output of the running application.


Thanks,

yolk

[pfalcon]

Ctrl+C doesn't have any effect, the application continues executing. Also, I don't get the debug output of the running application.

A can't reproduce this with a minimal test script. So, feel free to prepare a minimal code snippet to reproduce the issue, and submit a ticket on github with the exact steps to reproduce and related information (see viewtopic.php?f=16&t=1689 for more info).

[yolk]

Hi!

I just flashed a freshly compiled version (26b7d8a7b) onto my board (NodeMCU V3, the cheap one from China).
My boot.py is

Code: Select all

# This file is executed on every boot (including wake-boot from deepsleep)
import webrepl
webrepl.start()

import testapp
testapp.loop()

and testapp.py is

Code: Select all

import utime as time

def loop():
	while True:
		print(".")
		time.sleep(10)

Apart from setting up the network connection and uploading the scripts above, the board is in vanilla state. As I previously described, WebREPL prompts for the password and then does not show any reaction.

Can someone reproduce this?

Thanks in advance!

Thanks,

yolk

[pythoncoder]

@yolk I can reproduce this. I must admit it isn't obvious to me why this main.py fails to let me log in:

Code: Select all

import webrepl
import time
webrepl.start()
time.sleep(20) # Allow time for me to log in
import testapp
testapp.loop()

The following, of course, works. main.py

Code: Select all

import webrepl
webrepl.start()

Followed by (at webrepl prompt)

Code: Select all

import testapp
testapp.loop()

It would seem that the firmware needs to get to the Python prompt before webrepl can accept a login and provide a REPL.

[pfalcon]

Can someone reproduce this?

Thanks, with the details above, I was able to reproduce it. I'm looking into it.

[pfalcon]

This was fixed in master.

[yolk]

Hi!

This was fixed in master.

Works like a charm. Thanks!

Maybe that's a good time to emphasize that I'm really excited about the MicroPython project and the immediate help you and others provide!


Thanks,

yolk