We are going to look at a WS2812b led or neopixel in this example, again we use a Wemos mini and an RGB LED shield
Lets take a look a the shields and boards that are required
| Image | Summary |
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The Wemos mini – ESP8266 based board, it comes with various headers. This is the beauty of it you can create stackable projects with the board and pin compatible shields |
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An RGB LED shield – sometimes known as Neopixel |
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This is simply a base, you plug the Wemos Mini into one side and you can plug a shield or shields into the other side |
Parts List
1 x Wemos Mini
1 x Wemos Dual Base (optional)
1 x RGB shield
I connect the Wemos Mini to the dual base and then put the WS2812b shield along side this. You could stack these.
Code
This library is required – you can install these via the library manager
https://github.com/adafruit/Adafruit_NeoPixel
[codesyntax lang=”cpp”]
#include <Adafruit_NeoPixel.h>
#define NEOPIN D2
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(1, NEOPIN, NEO_GRB + NEO_KHZ800);
char SerialInput;
void setup()
{
// initialize journal printer sensors to default states
Serial.begin(9600);
pixels.begin(); // This initializes the NeoPixel library.
pixels.setPixelColor(0, pixels.Color(0, 0, 0)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
}
void loop()
{
// For a set of NeoPixels the first NeoPixel is 0, second is 1, all the way up to the count of pixels minus one.
SerialInput = Serial.read();
//verify incoming option
switch(SerialInput)
{
case ‘1’:
// RED ON
pixels.setPixelColor(0, pixels.Color(255, 0, 0)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
break;
case ‘2’:
// ALL off
pixels.setPixelColor(0, pixels.Color(0, 0, 0)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
break;
case ‘3’:
// GREEN ON
pixels.setPixelColor(0, pixels.Color(0, 255, 0)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
break;
case ‘4’:
// ALL off
pixels.setPixelColor(0, pixels.Color(0, 0, 0)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
break;
case ‘5’:
// BLUE ON
pixels.setPixelColor(0, pixels.Color(0, 0, 255)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
break;
case ‘6’:
// ALL off
pixels.setPixelColor(0, pixels.Color(0, 0, 0)); // Moderately bright green color.
pixels.show(); // This sends the updated pixel color to the hardware.
break;
}
}
[/codesyntax]
Output
Open the serial monitor and type in the number 1 to 6 to see a different colour on the LED
Links
Smart Electronics D1 mini – Mini NodeMcu 4M bytes development board based ESP8266 by WeMos
Dual Base Expansion board for WeMos D1 mini NodeMCU ESP8266
For WeMos D1 Mini RGB LED Shield Esp8266 For Wemos D1 Mini Shield Expansion Board For Arduino