MicroPython remote control: mpremote

The mpremote command line tool provides an integrated set of utilities to remotely interact with and automate a MicroPython device over a serial connection.

To use mpremote install it via pip:

$ pip install mpremote

The simplest way to use this tool is just by invoking it without any arguments:

mpremote

This command automatically detects and connects to the first available serial device and provides an interactive REPL. Serial ports are opened in exclusive mode, so running a second (or third, etc) instance of mpremote will connect to subsequent serial devices, if any are available.

Commands

For REPL access, running mpremote without any arguments is usually all that is needed. mpremote also supports a set of commands given at the command line which will perform various actions on remote MicroPython devices.

For commands that support multiple arguments (e.g. a list of files), the argument list can be terminated with +.

The full list of supported commands are:

  • connect to a specified device via a device-name shortcut:

    $ mpremote <device-shortcut>
    
  • connect to specified device via name:

    $ mpremote connect <device>
    

    <device> may be one of:

    • list: list available devices

    • auto: connect to the first available device

    • id:<serial>: connect to the device with USB serial number <serial> (the second entry in the output from the connect list command)

    • port:<path>: connect to the device with the given path

    • any valid device name/path, to connect to that device

  • disconnect current device:

    $ mpremote disconnect
    

    After a disconnect, auto soft-reset is enabled.

  • resume a previous mpremote session:

    $ mpremote resume
    

    This disables auto soft-reset.

  • perform a soft-reset of the device:

    $ mpremote soft-reset
    

    This will clear out the Python heap and restart the interpreter. It also disables auto soft-reset.

  • enter the REPL on the connected device:

    $ mpremote repl [options]
    

    Options are:

    • --capture <file>, to capture output of the REPL session to the given file

    • --inject-code <string>, to specify characters to inject at the REPL when Ctrl-J is pressed

    • --inject-file <file>, to specify a file to inject at the REPL when Ctrl-K is pressed

  • evaluate and print the result of a Python expression:

    $ mpremote eval <string>
    
  • execute the given Python code:

    $ mpremote exec <string>
    
  • run a script from the local filesystem:

    $ mpremote run <file>
    
  • execute filesystem commands on the device:

    $ mpremote fs <command>
    

    <command> may be:

    • cat <file..> to show the contents of a file or files on the device

    • ls to list the current directory

    • ls <dirs...> to list the given directories

    • cp [-r] <src...> <dest> to copy files; use “:” as a prefix to specify a file on the device

    • rm <src...> to remove files on the device

    • mkdir <dirs...> to create directories on the device

    • rmdir <dirs...> to remove directories on the device

    • touch <file..> to create the files (if they don’t already exist)

  • edit a file on the device:

    $ mpremote edit <files...>
    

    The edit command will copy each file from the device to a local temporary directory and then launch your editor for each file (defined by the environment variable $EDITOR). If the editor exits successfully, the updated file will be copied back to the device.

  • mount the local directory on the remote device:

    $ mpremote mount [options] <local-dir>
    

    During usage, Ctrl-D will soft-reboot and normally reconnect the mount automatically. If the unit has a main.py running at startup however the remount cannot occur. In this case a raw mode soft reboot can be used: Ctrl-A Ctrl-D to reboot, then Ctrl-B to get back to normal repl at which point the mount will be ready.

    Options are:

    • -l, --unsafe-links: By default an error will be raised if the device accesses a file or directory which is outside (up one or more directory levels) the local directory that is mounted. This option disables this check for symbolic links, allowing the device to follow symbolic links outside of the local directory.

  • unmount the local directory from the remote device:

    $ mpremote umount
    

Multiple commands can be specified and they will be run sequentially.

Auto connection and soft-reset

Connection and disconnection will be done automatically at the start and end of the execution of the tool, if such commands are not explicitly given. Automatic connection will search for the first available serial device. If no action is specified then the REPL will be entered.

Once connected to a device, mpremote will automatically soft-reset the device if needed. This clears the Python heap and restarts the interpreter, making sure that subsequent Python code executes in a fresh environment. Auto soft-reset is performed the first time one of the following commands are executed: mount, eval, exec, run, fs. After doing a soft-reset for the first time, it will not be done again automatically, until a disconnect command is issued.

Auto soft-reset behaviour can be controlled by the resume command. And the soft-reset command can be used to perform an explicit soft reset.

Shortcuts

Shortcuts can be defined using the macro system. Built-in shortcuts are:

- ``devs``: list available devices (shortcut for ``connect list``)
  • a0, a1, a2, a3: connect to /dev/ttyACM?

  • u0, u1, u2, u3: connect to /dev/ttyUSB?

  • c0, c1, c2, c3: connect to COM?

  • cat, ls, cp, rm, mkdir, rmdir, touch, df: filesystem commands

  • reset: reset the device

  • bootloader: make the device enter its bootloader

Any user configuration, including user-defined shortcuts, can be placed in the file .config/mpremote/config.py. For example:

commands = {
    "c33": "connect id:334D335C3138",
    "bl": "bootloader",
    "double x=4": "eval x*2",  # x is an argument, with default 4
    "wl_scan": ["exec", """
import network
wl = network.WLAN()
wl.active(1)
for ap in wl.scan():
    print(ap)
""",],
    "test": ["mount", ".", "exec", "import test"],
}

Examples

mpremote

mpremote a1

mpremote connect /dev/ttyUSB0 repl

mpremote ls

mpremote a1 ls

mpremote exec "import micropython; micropython.mem_info()"

mpremote eval 1/2 eval 3/4

mpremote mount .

mpremote mount . exec "import local_script"

mpremote ls

mpremote cat boot.py

mpremote cp :main.py .

mpremote cp main.py :

mpremote cp :a.py :b.py

mpremote cp -r dir/ :

mpremote cp a.py b.py : + repl