Telnet Server

[Roberthh]

As far as I could tell, importing & starting the telnet server reduced the free memory by 1616 bytes, and it's not frozen bytecode. As frozen bytecode, it's 640 bytes.

[pythoncoder]

Oops, sorry. Brain fade yesterday. Some figures based on frozen bytecode on the reference board.

Accessing via USB:
After import, usage 480 bytes
After starting server 608 bytes.

I then edited main.py to run it at boot, power cycled the board and accessed it over WiFi via Telnet. Usage (relative to the free RAM reported in the first test) was 1408 bytes.

[warren]

This is very useful. but I have a strange problem when typing.

I am connecting to the ESP8266 module over my LAN. I am using Putty for telnet. It connects immediately and in the Putty window I see the same flow of stuff on REPL as I am seeing through the serial connection.

When I type I cannot see what I am typing!

But what I type is definitely received and acted upon by REPL...its just that I cant see it when i am typing. And this applies to BOTGH the Putty console and on the serial view - when I am typing, nothing shows.

Also, CTRL-C does not work

Any hints?

Thanks

[Roberthh]

That seems to be a putty configuration problem. It seems to be in line edit mode. In the terminal setting of putty's configuration, set local line editing to force off. Then it works.

[warren]

That seems to be a putty configuration problem. It seems to be in line edit mode. In the terminal setting of putty's configuration, set local line editing to force off. Then it works.

Doh!

Thanks so much - works perfectly.

[jpj]

Very useful! Thank you for writing and sharing it.

[ttmetro]

Will this telnet server (or any other telnet) work with the standard (official) ESP32 microphython port?

[ I've been using the Pycom and the Loboris ports for this feature; both are (more or less) subtly different from standard microphython. ]

Bernhard

[Jongy]

Will this telnet server (or any other telnet) work with the standard (official) ESP32 microphython port?

[ I've been using the Pycom and the Loboris ports for this feature; both are (more or less) subtly different from standard microphython. ]

Bernhard

I've tried this now on an ESP32 and it doesn't work, getting this error:

Code: Select all

Traceback (most recent call last):
  File "utelnetserver.py", line 81, in accept_telnet_connect
OSError: stream operation not supported

which is quite expected by looking at the code, I admit.

Anyway I've come to a conclusion that I want telnet on my ESP32 because it would work much more smooth compared with the webrepl, so I'll keep you updated once I get this working

[Roberthh]

The change is simple. According to the hint here viewtopic.php?f=8&t=5868&p=33586&hilit=dupterm#p33586 add

Code: Select all

from uio import IOBase 

to the import section and change

Code: Select all

class Telnetserver()

into

Code: Select all

class Telnetserver(IOBase)

as shown below in the code snippet:

Code: Select all

import socket
import network
import uos
import errno
from uio import IOBase

last_client_socket = None
server_socket = None

# Provide necessary functions for dupterm and replace telnet control characters that come in.
class TelnetWrapper(IOBase):
    def __init__(self, socket):
        self.socket = socket
        self.discard_count = 0

[Jongy]

The change is simple. According to the hint here viewtopic.php?f=8&t=5868&p=33586&hilit=dupterm#p33586 add

Code: Select all

from uio import IOBase 

to the import section and change

Code: Select all

class Telnetserver()

into

Code: Select all

class Telnetserver(IOBase)

as shown below in the code snippet:

Code: Select all

import socket
import network
import uos
import errno
from uio import IOBase

last_client_socket = None
server_socket = None

# Provide necessary functions for dupterm and replace telnet control characters that come in.
class TelnetWrapper(IOBase):
    def __init__(self, socket):
        self.socket = socket
        self.discard_count = 0

Thanks! That really fixed it.

I was puzzled by this as I didn't realize which magic connects my object with its `write`, `readinto` methods to what `mp_uos_dupterm` accepts. `iobase_read` and `iobase_write` were what I missed...

The `uos.dupterm` should definitely be updated so people won't have to look in the code next time..