neopixel_ble_controller

This firmware controls an ESP32 with a 5x5 Neopixel (ws2812) grid.

This device is made to be used as a testing BLE peripheral for the bluerepl project.

A picture of the ESP32 and the full device :

Requirements

• Install ESP-IDF v4.4

Get started

Build

$ make

Flash

make flash

Ble services and characteristics

There is one service with three characteristics, one for sending commands one for reading the grid colors and a third one to send notifications when the button is pressed.

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Service UUID:

UUID: 8e72bbe5-f777-5284-7849-b4a0b2ac70d2

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Characteristic for sending commands:

UUID: 0000beb6-0000-1000-8000-00805f9b34fb
Properties: WRITE / WRITE WITHOUT RESPONSE

Commands

• 0x01 => clear the grid

• 0x02[x][y][r][g][b] => set a pixel color

  example:

  uint8_t payload[] = {0x02, 0x02, 0x02, 0xff, 0x00, 0x50};
  // send payload
  
  // Will set the color of the pixel at x=2 and y=2 to color 0xff0050

• 0x03[r][g][b] => set the color of all the pixels (same color for all pixels)

  example:

  uint8_t payload[] = {0x03, 0xff, 0x00, 0x00};
  // send payload
  
  // Will set the color of all the pixels to color 0xff0000

• 0x04{[r][g][b], ... * 25} => set the color of all the pixels one by one

  example:

  uint8_t payload[] = {0x04, 0xff, 0x00, 0xff, 0x00, 0xff, 0x50 /*...*/};
  // send payload
  
  // Will set the first pixel to 0xff00ff the second to 0x00ff50 and so on ...

• 0x05[brightness] => set the brightness of all the pixels

  The brightness must go from 1 to 20.

  example

  uint8_t payload[] = {0x05, 0x01};
  // send payload
  
  // Will set the brightness to 1 (the lowest brightness)

• 0x06 => turn on the leds

• 0x07 => turn off the leds

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Characteristic for reading pixels color:

UUID: 0000cad8-0000-1000-8000-00805f9b34fb
Properties: READ

The colors will be arranged like this

typedef struct {
    uint8_t r;
    uint8_t g;
    uint8_t b;
} rgb_color_t;

rgb_color_t the_array_you_receive[25];

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Characteristic for button notifications:

UUID: 0000dac4-0000-1000-8000-00805f9b34fb
Properties: READ / NOTIFY

When the button is pressed it will increment a counter and notify it's value.