Problems with running MicroPython on ESP8266 with 512K

In my previous post about running MicroPython on ESP8266, I mentioned that ESP8266 boards may have different amount of flash. Similarly there are two versions of MicroPython: limited version for 512K, and full version for boards which have more than 512K of flash. In that post, I played with ESP-07 which had only 512K, so I had to use a limited version of MicroPython. This limited MicroPython version was enough just to turn on/off an LED, but it turned out that it actually doesn’t work well.


After successful flashing ESP8266 with limited MicroPython, I tried to upload a simple script which just turns on/off an LED in a loop:

import time
from machine import Pin

pin = Pin(13, Pin.OUT)
while True:

I tried a couple of tools, but nothing worked.

rshell reported the following error:

$ sudo rshell --port /dev/ttyUSB0 
Connecting to /dev/ttyUSB0 ...
Traceback (most recent call last):
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 1184, in connect
    ip_address = socket.gethostbyname(port)
socket.gaierror: [Errno -2] Name or service not known

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/rshell", line 9, in 
    load_entry_point('rshell==0.0.9', 'console_scripts', 'rshell')()
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 4, in main
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 2644, in main
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 2606, in real_main
    connect(args.port, baud=args.baud, wait=args.wait, user=args.user, password=args.password)
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 1190, in connect
    connect_serial(port, baud=baud, wait=wait)
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 1214, in connect_serial
    dev = DeviceSerial(port, baud, wait)
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 1434, in __init__
    Device.__init__(self, pyb)
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 1269, in __init__
    self.root_dirs = ['/{}/'.format(dir) for dir in self.remote_eval(listdir, '/')]
  File "/usr/local/lib/python3.5/dist-packages/rshell/", line 1351, in remote_eval
    return eval(self.remote(func, *args, **kwargs))
  File "", line 0
SyntaxError: unexpected EOF while parsing

And mpfshell reported this:

$ sudo mpfshell

** Micropython File Shell v0.7.6, ** 
-- Running on Python 3.5 using PySerial 3.2.1 --

mpfs [/]> open ttyUSB0
Connected to esp8266
mpfs [/]> ls
Traceback (most recent call last):
  File "/usr/local/bin/mpfshell", line 8, in 
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 687, in main
  File "/usr/lib/python3.5/", line 138, in cmdloop
    stop = self.onecmd(line)
  File "/usr/lib/python3.5/", line 217, in onecmd
    return func(arg)
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 205, in do_ls
    files =
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 503, in ls
    files =, add_files, add_dirs, add_details)
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 43, in f_retry
    return f(*args, **kwargs)
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 169, in ls
    res = self.eval("os.listdir('%s')" % self.dir)
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 150, in eval
    ret = self.exec_('print({})'.format(expression))
  File "/usr/local/lib/python3.5/dist-packages/mp/", line 157, in exec_
    raise PyboardError('exception', ret, ret_err)
mp.pyboard.PyboardError: ('exception', b'', b'Traceback (most recent call last):\r\n  File "", line 1, in \r\nAttributeError: \'module\' object has no attribute \'listdir\'\r\n')

WebREPL didn’t work either. After connecting to the board via USB-Serial adapter, and trying to start WebREPL, it reported the following error:

could not open file '' for reading
could not open file '' for reading

MicroPython v1.8.7-292-g3d739eb on 2017-02-18; ESP module with ESP8266
Type "help()" for more information.
>>> import webrepl_setup
Traceback (most recent call last):
  File "", line 1, in 
  File "", line 111, in 
  File "", line 80, in main
  File "", line 49, in get_daemon_status
AttributeError: 'NoneType' object has no attribute '__exit__'

I have not looked into the problems above, but looks like that limited MicroPython doesn’t contain something which is required for those tools. Or, this may be just a bug.

Finally, I found an ESP8266 board with 1M of flash, so that I could use full MicroPython (in my case, it was v1.8.7). And it worked! I was able to upload a Python script to the board. Here is how it can be done with mpfshell:

$ sudo mpfshell

** Micropython File Shell v0.7.6, ** 
-- Running on Python 3.5 using PySerial 3.2.1 --

mpfs [/]>; open ttyUSB0
Connected to esp8266
mpfs [/]>; ls

Remote files in '/':

mpfs [/]> put
mpfs [/]> ls

Remote files in '/':
mpfs [/]>

After resetting the board, I was happy to see that the LED was blinking.

The conclusion is obvious:

  • Buy ESP8266 with more than 512K of flash
  • Use full version of MicroPython

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One thought on “Problems with running MicroPython on ESP8266 with 512K

  1. Avatarpfalcon

    We’re looking for maintainers for 512K version of MicroPython, i.e. for people who’d care about such modules, and submitted patches to smooth the rough edges as you found. But, there doesn’t seem to be such people (who’d want to go as far as to submit patches), because indeed, you won’t be able to to much with 512K anyway (the biggest limitation is lack of file system, and there’s simply no room for it). So, the most time/cost effective solution is just using modules with a bigger flash, like you did.


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