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Button pins

The MacroBoard uses seven GPIO pins for button inputs, configured with internal pull-up resistors.
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GPIO 4
Toggle shuffle mode on/off in Spotify playback
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GPIO 5
Decrease playback volume
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GPIO 12
Increase playback volume
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GPIO 13
Toggle repeat/loop mode in Spotify
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GPIO 14
Skip to previous track
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GPIO 25
Toggle play/pause state
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GPIO 26
Skip to next track

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I2C pins

The OLED display uses the I2C protocol for communication.
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GPIO 21
I2C data line for OLED display communication
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GPIO 19
I2C clock line for OLED display communication
The I2C bus runs at 400 kHz for faster display updates.

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LED pin

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GPIO 18
WS2812B RGB LED strip data pin

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RGB LED configuration

The MacroBoard uses an addressable LED strip for visual feedback.
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WS2812B
Addressable RGB LED chip
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20
Number of LEDs in the strip
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GRB
Green-Red-Blue color byte order
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230
Maximum brightness level (0-255)
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5V @ 500mA
Maximum voltage and current draw
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100 Hz
LED updates per second
Ensure your power supply can handle 500mA at 5V when running all 20 LEDs at full brightness.

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OLED display configuration

The display uses the SSD1306 driver with I2C communication.
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SSD1306
OLED display controller chip
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128x64
Display width and height in pixels
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0x3C
Hardware I2C address for the display
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-1
No hardware reset pin used (software reset only)
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400 kHz
I2C bus frequency

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Pin initialization

All button pins are configured as inputs with internal pull-up resistors enabled. The buttons should connect the GPIO pin to ground when pressed.
The I2C pins are configured with pull-up resistors:
The ESP32’s internal pull-up resistors are sufficient for button debouncing and I2C communication. External pull-up resistors are not required.

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Hardware connections

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Button wiring

Each button should be wired as follows:
  • One terminal to the GPIO pin
  • Other terminal to GND
  • No external resistors needed (internal pull-ups are used)

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LED strip wiring

  • Data: GPIO 18
  • VCC: 5V power supply
  • GND: Common ground with ESP32

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OLED display wiring

  • SDA: GPIO 21
  • SCL: GPIO 19
  • VCC: 3.3V or 5V (depending on display module)
  • GND: Common ground with ESP32
Ensure all components share a common ground connection with the ESP32 to prevent communication issues.