MicroPython – Nodes examples with DHT11, Relay and MQTT

In a series of articles seen previously  on Mqtt, Beaglebone and ESP8266

Mqtt with Beaglebone and ESP8266 – Articles List

we have created the infrastructure for managing the ESP8266 nodes .

In this article we program the two ESP8266 nodes  using MicroPython instead of Nodemcu and Lua.

The infrastructure remains identical; on the Beaglebone there is Mqtt Mosquitto Server and Freeboard for the management of the mqtt topics, visualization and interaction.

The ESP8266 node examples with relay and DHT11 sensor use the umqtt MicroPython libraries, available on the site

umqtt simple

In the following examples, only the umqtt simple is used; in the code several delays have been inserted to allow the board to manage the messages and not run into errors; in the case the Mqtt server is not available the code restarts the board.

Below the code used for these examples.

Node with DHT11 sensor

  • boot.py: code executed at startup

  • umqtt/simple.py:  mqtt library

  • dht11.py: module for reading the temperature and humidity on the GPIO2

  • main.py: code executed after boot

  •  client_mqtt.py: Main module for node management

  • riavvia.py: service code to restart the module from uPyCraft

 

Node with relay

  • boot.py: code executed at startup

  • umqtt/simple.py: mqtt library

    • main.py: code executed after boot

    •  client_mqtt.py: Main module for node management

  • riavvia.py: service code to restart the module from uPyCraft

Below is the filesystem on ESP8266 for the relays sample

ESPFilesystemBy accessing Freeboard we have the same informations obtained with Nodemcu and LUA on ESP8266 nodes

FreeboardMicroPythonBelow are the screens with MQTT Dashboard installed on an Android smartphone, with the possibility to check the status of the relay, read the sensor parameters, restart and sleep the two nodes

MqttPublish

MqttSubscribe

Here are the links to download the two examples

DHT11 sensor sample

Relay sample

In the next article we will compile the MicroPython firmware for ESP8266.

 

 

 

 

MicroPython – MicroPython program structure

After reviewing various development tools for MicroPython in previous articles

MicroPython – Development tools Ampy – Eric

MicroPython IDE uPyCraft

in this article we briefly describe the main features of MicroPython. In particular, we examine the documentation relating to the ESP8266, but the concepts can also be extended to the other boards.

The documentation on the ESP8266 soc and MicroPython  is available at the link

ESP8266 MicroPython Documentation

At the link we can find all the informations necessary to implement the code on the card and the features of MicroPython as well as the differences compared to Python.

Here are the main points for coding in MicroPython:

  • MicroPython has a REPL (Read Evaluate Print Loop) console through the serial port to which the device is connected on which we can give the various MicroPython commands interactively.
  • The REPL console can also be accessed via connection to the IP address of the device by enabling the WEBREPL (Web Browser Interactive prompt) console

WebREPL Documentation

importing the webrepl package, enabling it and starting it at each device restart. To access the configured device, we can use the link

WEBREPL Access

or locally cloning it  from github

  • At the start of the device the system runs boot.py and after main.py.
  • The MicroPython libraries are available on the github at the link

MicroPython libraries

  • Additional packages

The additional modules can be downloaded from the link of the libraries presented above or downloaded with the upip utility (Package Manager) from the REPL console if available in the Python Package Index (PyPI) repository

PYPI

as described below

upip

Below is a simple example that connects to the router and allows us to access the MicroPython console with the browser and WEBREPL.

  • boot.py code

At the first access it is required to enable webrepl to be executed in the REPL console with the command

we can activate the service and the access password.

The procedure generates the webrepl_cfg.py file on the device.

After setting up and restarting, we access the web console by opening the locally cloned webrepl.html file with a browser

WebreplPressing connect and after entering the password ,set in the initial setup, we access the console

WebreplConnectedNow we install from the WEBREPL console, for example, the stat module using upip

To paste commands  execute Ctrl+A e Ctrl+V

WebreplupipIn this case the package was taken from the PYPI repository, unpacked and installed on the device.

We have noticed that some modules, although available on the repository, give an error during installation with upip; these modules are installed directly without using the upip utility,but by downloading the library from the site listed above and transferring the code to the device.

Here is the link of the code shown above

Webreplsample

Another option available is to build  the firmware with the required modules.

In the next article we will examine examples similar to what was done with LUA on ESP8266 in previous articles

MicroPython – Nodes examples with DHT11, Relay and MQTT

 

 

 

Micropython – Development tools Ampy – Eric

After the  uPyCraft  intallation in the previous article

MicroPython – IDE MicroPython uPyCraft

let’s now look at other tools available for the development in MicroPython for various platforms.

This article shows the operations to be performed on Windows and Linux.

First Python package to install is Ampy (Adafruit MicroPython Tool)

ampy

The tool is available in the python repositories, so it can be installed using the  pip tool.

In Windos run in a dos command prompt

Similarly in Linux run in a shell

The available commands are listed running

ampyAmpy allows the transfer, creation, viewing, and execution of files on the device.

As for the IDE you can install Eric, generic Python IDE

Eric

Eric does not allow communication from the IDE with the device as seen with uPyCraft; this task is delegated to Ampy. For the installation proceed as follows:

  • For Linux Debian 9 just run

The tool is available among the development tools; at the first execution it requires default settings

ericSettingsWe define the workspace location

ericWorkspaceand we have the access to the IDE

eric

  • For Windows download the zip

Eric

Unzip the zip into a folder from which we run it; install the prerequisites

Perform the eric installation at this point by double clicking on install.py

ericInstallWindowsThe program checks the prerequisites and completes the installation

ericWindowsProcedure

Clicking twice on eric6.py or running eric6 from a dos command prompt we run the program in the same way as seen for Linux Debian

ericWindows

In the next article we will briefly examine how a MicroPython program is structured

MicroPython – MicroPython program structure

 

Micropython – MicroPython IDE uPyCraft

After installing the firmware on the Nodemcu esp8266 DevKit board

MicroPython Firmware

let us now examine a development tool can be suitable for the development of Python code.

A tool that allows both to write code and upload it to the device is uPyCraft

uPyCraft

The tool currently works for Windows and from version 0.30 is also available for Linux; the source code is available at the link

uPyCraft Source

Here are the steps for Windows and Linux.

  • Windows

Once downloaded the package we must  run it as an administrator; the installation of the Monaco font is required

monaco-font

After the font installation,  we have the access to the IDE

upycraft-v0-29We set the Location in Tools->Preferences->Language Location

upycraftlocation

and the serial port paramenters in Tools->Preferences->Serial

upycraftserialsettingsWe plug the device into an USB port and set the serial port on uPyCraft

upycraftserialWe choose the device type; in this case it is ESP8266

upycraftdeviceBy clicking on the connection icon we access to the device and view the files on it

upycraftconnectionThe firmware installation expands on the device only the Python file boot.py

upycraftfilesystemThe tool allows to download examples of MicroPython code for the board, blink.py for example

examplesClicking the “Download and Run” button we load the code onto the device and run it

blinkIn this example the led of the Nodemcu DevKit blinks.

  • Linux

The tool is similar in the Linux version; once downloaded the package to which we have to assign  the execution right we run it. We must assign to the user the access to the serial port with the command, already seen above

In our case, on Debian 9, we have the following screens similar to what we saw on Windows.

In the uPyCraft IDE

upycraft-v0-30linuxWe set the Location in Tools->Preferences->Language Location

upycraftlocationlinux

and the serial port paramenters in Tools->Preferences->Serial

upycraftserialsettingslinuxWe plug the device into an USB port and set the serial port on uPyCraft

upycraftseriallinuxWe choose the device type; in this case it is ESP8266

upycraftdevicelinuxBy clicking on the connection icon we access to the device and view the files on it

upycraftconnectionlinuxThe firmware installation expands on the device only the Python file boot.py

upycraftfilesystemlinuxThe tool allows to download examples of MicroPython code for the board, blink.py for example

exampleslinuxClicking the “Download and Run” button we load the code onto the device and run it

blinklinuxAs in Windows the led of the Nodemcu DevKit blinks..

In version 0.30 for Windows we noticed some bugs, so for this operating system we continue to use the uPyCraft  version 0.29.

Further informations about uPyCraft can be found at the following site

uPyCraft Documentation

In the next article we will discuss another Python development tool

MicroPython – Development tools Ampy – Eric

MicroPython – Python on embedded devices

In this article we begin to treat MicroPython

MicroPython

an implementation of Python3

Python

for embedded devices.

Various images are available on the MicroPython website for different devices, including the modules esp8266 and esp32

MicroPython Dowloads

We start our tests with a Nodemcu esp8266 DevKit

Nodemcu Devkit

We proceed to load the firmware  on this card.

The Micropython site also refers how to load the firmware on the cards; these informations are available at the link

MicroPython Tutorial for esp8266

To load the firmware we always use the tool esptool, also available on the Python repository.

To be able to use it, we need to install Python3 on our development platform. Here are the steps to follow for Windows and Linux.

  • Windows

For windows we must first install the Python3 environment, available at the following link

Python for Windows

In our case, we downloaded the  version 3.6.4 for 64-bit systems. We installed the package  with administrative rights

setuppythonAfter proceeding to add Python in the Path we click “Install Now”

pythonsetupendAfter the installation, we open a dos command propmt and check the installed Python version

pythonversionAlways from the dos command prompt we proceed to the installation of esptool with the command

esptoolinstallationAt this point we can proceed to the MicroPython firmware upload on the Nodemcu esp8266 DevKit. Of course, it is necessary to have the serial-ttl drivers installed for your DevKit model on Windows. Now go into  the folder where the firmware has been downloaded  and run the following  commands from the dos command prompt

erase_flashProceed to load the firmware

firmware_flashOnce the firmware is installed  we log on the Python console using, in our case with the nodemcu card DevKit, the same port already used to load the firmware.

On Windows we can use Putty

Putty

and set the serial connection to 115200 baud rates

repl_putty

  • Linux

For Linux we use the Debian 9 distribution, but the procedure can be extended to other distributions. After installing Debian 9 , similar to version 8

Debian 8

we proceed to the installation of Python3 and esptool from a Linux shell

Add the user used on Debian to the dialout group

In our case, using  sviluppo as a user, the command is as follows

Let’s move on to install the Python esptool package

We can then proceed with the installation of the firmware in the same way as done on Windows.

We check on which serial port the card is available (ttyUSBX)

ttylinuxWe perform a flash erase and firmware upload

To log on the DevKit we use screen

Here is the manual of the tool

Screen Manual

To detach from screen press

instead to resume run

To quit screen

Once connected you get the same result as Windows

screenIn the next article we will begin to see which IDEs can be used to create and load our Python code

MicroPython IDE uPyCraft

 

ESP32 Wifi-Bluetooth Module

In this article we describe briefly the ESP32  chip from Espressif

ESP32

This lower power SOC  contains a 32 bit MCU  with bluetooth and wifi modules. At the Espressif web site we can find the detailed informations about the ESP32

ESP32 Resources

The device datasheet is available in the following pdf document

ESP32 Datasheet

The ESP32 modules are available individually or in a development kits; the last system simplifies its usage as the development kit contains all the hardware to use rapidly the soc device; we are already ready to load the firmware and use the device.

On internet various web sites describe home automation or iot projects using this soc.

A reference site for the ESP32  is

esp32

At above link we can find the various development platforms utilized  for the ESP32. The most relevant  are

  • Arduino Ide

ESP32 Arduino

  • ESP-IDF

ESP32 IDF

  • Micropython

MicroPython

  • PlatformIO

PlatformIO

  • Firmware Lua

LuaNode

Lua-RTOS-ESP32

Nodemcu Development

We can buy the ESP32 modules/dev kits from various internet online websites, for example ebay

ESP32 on ebay

Different ESP32  modules are available from different vendors

Espressif esp-wroom-32

AI-Thinker esp32s

At the link

http://esp32.net/

different hardware configurations available are listed.

As development kits we report

AI-Thinker NodeMCU-32S

DoIT ESP32 Dev Kit

There are development kits based on esp32 that also integrate a LORA wireless  module internally

Lora

We report for example the following

Heltec Wifi LoRa 32

TTGO LoRa32

In the next articles we’ll describe how to build firmwares and use the ESP32 MCU.

OctoPrint installation on Orange PI PC – Print Test File

After the OctoPrint server configuration

Printer settings

we set the connection parameters for the printer.

After connecting to the OctoPrint server with the octoprint user and password as password, we set up the printer connection

octoprint-connessione

With these settings it is possible to print a gcode file already generated with Cura or Slic3r

Cura

Slic3r

or upload a stl file on which the slice will be executed using the loaded cura profile and the CuraEngine on the Orange Pi PC system.

In the case where a stl file is imported, the slicing of the file is proposed

octoprint-sliceAt this point the file is ready for printing

octoprint-fileslicedOnce the printing is started, the progress and temperature can be checked

octoprint-progressbaras the layers that are being created

octoprint-sliceprogressIn this example, the basic settings were used to start the system for the first time.

For further information and configurations on OctoPrint refer to the software documentation

Octoprint Documentation

At the following link the supported printers are listed

Supported printers

OctoPrint installation on Orange PI PC – Printer Settings

After  defining the local hostname resolution

Local Hostname Resolution

at this point it is necessary to configure the printer.

WARNING: Use of the settings shown is at your own risk. We assume no responsibility if these settings cause malfunctions or breakage of the printer.

At the first access to OctoPrint, the basic parameters for managing the printer are requested. In our case, we connect the Orange PI PC to an Anet A8 3d printer via the USB port. At the first access to the address

http://3dprinter.local

 a configuration mask is shown

octoprint-accesspressing next we access the next screen where to define the user who manages the printer with his password

octoprint-accesscontrolWe press Keep Access Control; the next step is  the control of the Internet connection in which we disable the Connectivity Check

octoprint-accessconnectivityWe have to import our cura profile for Anet A8 and set  the path to the executable CuraEngine, compiled in the previous article

Octoprint Installation

octoprint-printerprofile

octoprint-curaengine

The imported profile must be generated by Cura 15.04.x or older. Below is the link to the various versions of the Cura software

Cura

We can now define the parameters of the printer, in our case Anet A8

octoprint-printer1We set the bed size and print volume

octoprint-printer2The speed of movement using the control panel is defined in the next step; we set up conservative parameters

octoprint-printer3Finally, we set the extruder parameters

octoprint-printer4

At the next screen we set the commands to be sent to Debian directly from OctoPrint; they are set as follows

octoprint-command

where in the password you must enter the password to run the root commands on Debian.


The folder in which Octoprint has been installed is inserted for the software update

octoprint-swupdateWe do not insert anything for the webcam

octoprint-webcamFinally, the configuration is completed with the Finish button.

octoprint-finishFor more OctoPrint settings and addons refer to the site

OctoPrint

In the next article we’ll print a test model

Print test file

OctoPrint installation on Orange PI PC – Local Hostname Resolution

After configuring haproxy for the use of content in http on the standard port

HAProxy Installation

we configure the Linux machine to publish the hostname on the network with the avahi daemon.

On Linux and OSX machines this service is natively visible, while for Windows systems it is necessary to install the Bonjour service

Bonjour application for windows

On the Orange PI PC the avahi daemon must be installed with the command

We change the name to which our 3D print server must match in the two files /etc/hosts and /etc/hostname

In our case the name orangepcpc has been changed to 3dprinter.

Restarting the linux box, the services are accessible  using the name 3dprinter.local.

avahiIn the next article we’ll show a printer configuration

Printer Settings

OctoPrint installation on Orange PI PC – HAProxy Installation

After the automatic start of OctoPrint configuration

OctoPrint Autostart

at this point we can set up the system to answer to the standard port of an Http server.

For this purpose we install and configure the HAProxy reverse proxy

HAproxy

Proceed to the installation

Edit the /etc/haproxy/haproxy.cfg file and add to the default the directives including also the use of webcam

Restart the proxy with the command

Restart the Orange PI. If everything is configured correctly, the 3D print server answers on port 80  of the Orange Pi PC ip address

http://ORANGEPIPC_IP

haproxyIt is possible to map the Octoprint service on port 5000 only to the loopback interface by editing the file ~/.octoprint/config.yaml

and adding the host reference under the server directive

Restart OctoPrint

Now the 5000 port is mapped only with the address 127.0.0.1.

In the next article, we’ll configure Linux to publish the hostname on the network so that it can be accessed through this reference without using the IP address

Local Hostname Resolution

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