Accessing Micro Python on the IoT Node
Introduction
Once micro Python is running on the node we must be able to upload Python programs on the node and execute them there. In case of processor board with a micro-USB connector it is easy to connect to the micro Python REPL loop through a simple serial interface and a terminal emulator like
minicom. In addition you can use
ampy to up - and download files. A standard editor like
emacs or a specify Python editor like
idle can be used to edit the Python code.
More comfortable though is the use of an IDE like uPyCraft which has editing, up and download features, library functions and a collection of examples built in. uPyCraft can be found as binaries for Windows, Mac and Linux.
When trying to install the
Linux binary I got problems with library version incompatibilities on zlib but even when solving this problem the program did not work as expected (the Windows version worked fine). uPyCraft is a Python program whose source is available on github. In fact I found 2 versions:
Even tough I managed to run the program and the main window came up on the screen, most of the functions gave problems. The Qt5 version even more than the Qt4 version. Finally I decided to modify the QT5 version of the program myself and to try correct the errors one be one until the program could be used for the AFNOG workshop. Since the original documentation is also obsolete I re-wrote it for my
new version. For a description on how to use the program please refer to the github Wiki pages.
Accessing micro Python over WiFi
Unfortunately uPyCraft relies on the serial connection between the PC on which it runs and micro Python on the IoT node. When taking the ESP01 off its "programmer" this serial connection will be cut and uPyCraft, in its current state, cannot be used any longer. It is however possible to enable
webrepl on the micro Python node, allowing access to the REPL loop through a
websocket interface.
In order for this to work we first must enable the webrepl server:
Connect the node to the programmer to get access through the serial interface and type
import webrepl-setup
and follow the instructions.
Then install the
webrepl client on your PC. Start the browser and enter the URL file://directory_of_webrepl/webrepl.html. In the window coming up enter the websocket server consisting of ws://IP_of_your_IoT_node:8266, where 8266 is the port number. After entering the password you defined during the webrepl_setup step you should get connected to the REPL loop of your micro Python IoT node. For more information please consult the
micro Python tutorial.
As you can see, There are also buttons available to transfer files from and to the IoT node.
--
Uli Raich - 2019-03-01
Comments