A simple script for controlling RGB LEDs with NodeMCU
You will need a means to flash the firmware binary to your ESP. Install esptool.py using pip
# pip install esptool
Also, you will have to persist the init.lua script to the ESP's flash memory. This can be done either by writing lua code manually to the serial port of the ESP or preferably by using a tool like ESPlorer.
Connect a NodeMCU to your computer. Then, in flash.sh, edit the esptool.py --port parameter to point to the NodeMCU serial port.
Make sure the device is ready to be flashed. Now, execute flash.sh to flash the firmware binary.
$ ./flash.sh
Edit init.lua and change the WIFI_SSID and WIFI_PASS variables to whatever the login credentials for your wireless network are.
Using ESPlorer or any other method, write init.lua to your NodeMCU's flash memory.
The ESP should now connect to your wireless network every time you power it up. Find out its IP address, either by querying it via serial (wifi.sta.getip()), by looking it up on your DHCP server (i.e. router) or performing a host discovery (i.e. nmap -sP 192.168.1.0/24).
Now, you can send color data to it using its UDP protocol.
nc -u IP-ADDR 1337
The data format is defined as follows:
<message> ::= [<subnode>:]<hexcolor>\n
<subnode> ::= <id>(\.<id>)*
<id> ::= a-zA-Z0-9
<hexcolor> ::= <hexdigit> | <hexdigit>{3} | <hexdigit>{6}
<hexdigit> ::= 0-9a-fA-F
Some simple examples:
00f blue
00ff71 cyan
f white
0 black