smh_nodemcu

This project is a recopilation of utilities and howto documentation to ease software development into the NodeMCU IoT platform based on the ESP8266 chip.

Table of contents

• Getting started
• Commands
• Firmware
• Examples
• Links

Getting started

Requirements

• git
• make
• Python2.7
• virtualenv

Installation

Clone the project.

cd
mkdir projects
cd projects
git clone https://github.com/samuelmh/smh_nodemcu.git

Install the environment

cd ~/projects/smh_nodemcu
make install

It will create a virtualenv for the project in ~/projects/venvs/smh_nodemcu

Permissions

You have to be a member of the dialout group. Check it!

groups

If you are not a member, add your user to the group.

sudo adduser $USER dialout

You will need to log again in your system to see if you are in the group.

Activation

This commands have to be executed prior to operate inside the new environment.

cd ~/projects/venvs/smh_nodemcu
source bin/activate

Now you have access to the nodemcu command in the shell.

Port

To detect the device or port of your board, plug it to the USB port of your computer and type.

dmesg|tail

You will get a message like:

[  859.743947] usb 3-1: New USB device found, idVendor=1a86, idProduct=7523
[  859.743953] usb 3-1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  859.743956] usb 3-1: Product: USB2.0-Serial
[  859.784581] usbcore: registered new interface driver usbserial
[  859.784601] usbcore: registered new interface driver usbserial_generic
[  859.784619] usbserial: USB Serial support registered for generic
[  859.785465] usbcore: registered new interface driver ch341
[  859.785484] usbserial: USB Serial support registered for ch341-uart
[  859.785506] ch341 3-1:1.0: ch341-uart converter detected
[  859.786420] usb 3-1: ch341-uart converter now attached to ttyUSB0

The last line, shows the board port is the device /dev/ttyUSB0.

NOTE: by default, the programs use /dev/ttyUSB0 as the default port, so if this is your case, you don't have to worry. If your port is different, you will have to type the port argument every time you call a program.

Test

Connect to the board. You will have to change the port to your case.

Example:

nodemcu --port=/dev/ttyUSB0 terminal

You will be in the terminal, press the reset button of the board and some letters will appear in the screen. Press Ctrl+D to exit.

Commands

Once the installation is done, there will be the nodemcu command available inside the virtualenv. It provides some useful features.

Type nodemcu --help to get the available options and commands.

Terminal

The terminal is a convenient way to interact directly with the board.

Type nodemcu terminal --help to get the available options.

Type nodemcu terminal to connect to the board. Then you can send commands. If you press the reset button, you will get a message like this.

NodeMCU 1.5.4.1 (SMH all-modules) build 27-Nov-2016 powered by Lua 5.1.4 on SDK 1.5.4.1(39cb9a32)
lua: cannot open init.lua
>

To exit the terminal, just press CTRL+D.

Testing files

It is possible to execute the lines of a file in the board and then open a terminal. This is done with the --file option and it is useful to test the correctness of a script before uploading it as a permanent file.

File manager

The file command is the way to manage the files/scripts that will go in the board.

These are the subcommands:

• add: upload a file to the board.
• cat: read a file from the board.
• ls: show files and sizes inside the board.
• mv: rename a file inside the board.
• rm: remove a file from the board.

If you want a script to be executed when the board boots up, name it init.lua.

Type nodemcu file --help to get more information.

Firmware

Some boards do not have the latest firmware or can cause trouble. For these cases, this project provides binaries and utilites to ease the process of flashing the chip.

The Makefile provides some commands, so if you type make flash-float-4mb or flash-integer-4mb, the latest firmware will be uploaded to the board.

Example:

make flash-float-4mb port=/dev/ttyUSB0

For more information, please see the firmware documentation

Examples

There are some samples in the lua-utils folder that can be used to test the NodeMCU capabilities as well to inspire your code. These are the current scripts:

• examples/wifi_ntp_http-server.lua: connects to an access point, takes the UTC time from a NTP server, set its internal clock and servers timestamps through a HTTP server.
• utils/GM009605.lua: class to print messages on a GM009605 128x64 screen.

External projects

• iot-gateway-custom: example of a 3 layer architecture: thing-gateway-MQTT broker.
• iot-project-feelings: set a feeling on a dial servo wheel controlled over MQTT.
• iot-project-presence: detect presence with a PIR sensor and communicate over WiFi-MQTT.

Tutorials - Hands On

• Introduction
• Communications

Links

• NodeMCU Official page
• Official NodeMCU documentation
• Firmware (Github)