Led Counter – Arduino ESP8266

mai 11, 2022

Led Counter – Arduino ESP8266

This is an old project, built for a friend who meant to run it as a standalone smart object at restaurants, hotels and point of sales. I had fun building the proof-of-concept, pity there was nobody to pick it up after the handover!

The sketch runs on a Chinese Arduino clone (ESP8266) that sports a WIFI chip, amongst other interesting features.

ESP8266 Reference

This sketch fetches social media statuses from a web page.

The board will attempt to connect to a web page at boot, and return a JSON array of social network field values. The page is currently purposefully very sparse as to allow for custom implementation.

In order to run, the PHP page must reside on an accessible server, and the DATA_PROVIDER field needs to be defined in config.h.

Icons

Icons are defined in the main header.h file. They are stored in flash memory in order to access them more quickly using PROGMEM.

Each icon is composed of a 2 dimensional byte array of 8×8 to reproduce each NeoPixel panel and can display up to 3 colors by design .

Here’s an example for a Skull icon:

const byte PROGMEM _SkullIcon[8][8] = {
  {0, 2, 2, 2, 2, 2, 2, 0},
  {2, 2, 2, 2, 2, 2, 2, 2},
  {2, 1, 1, 2, 2, 1, 1, 2},
  {2, 1, 1, 2, 2, 1, 1, 2},
  {2, 2, 2, 2, 2, 2, 2, 2},
  {2, 2, 2, 2, 2, 2, 2, 2},
  {0, 2, 2, 1, 1, 2, 2, 0},
  {0, 2, 2, 1, 1, 2, 2, 0}
};

const RGB PROGMEM _SkullIconColors[3] = { 
  {0, 0, 0}, //Background
  {255, 0, 0}, // eyes
  {255, 255, 255} //bone
};

Drawing the icon

In the above Skull icon definition, each “line” in the array will turn on a pixel, or keep it off. This allows us to have a 8×8 ( 64 😀 ) pixels canvas to draw our icons.

Looking at the first array item, we see that the first and final pixels are left off (black) and that the other 6 pixels are set at a value of 2. This means that the pixel is turned on, and that it will use the 2 color from the RGB color array.

Colors

In the case of the Skull icon above, each pixel is either on (1 or 2) or off (0). The on values of either 1 or 2 will define which RGB color it is to pick from the RGB Struct.

Array[0] from the RGB struct is set at {0, 0, 0}, the pixels will be set to off
Array[1] from the RGB struct is set at {255, 0, 0}, the pixels will be set to red
Array[2] from the RGB struct is set at {255, 255, 255}, the pixels will be set to white

To create your own icon, you can use add your own arrays such as _MyCustomIcon[8][8] and _MyCustomIconColors[3].

Configuration Parameters

config.h

BRIGHTNESS – This percentage value will set the brightness of the NeoMatrix pannels. They are very bright, I usually run them at 25%.
PIN – Set your default ESP8266 pin number