Wiring & Pinout
===============

The firmware supports two board profiles, selected during setup: **Generic** (a
normal ESP32 dev board with a separate e-paper display) and **Waveshare** (the
Waveshare ESP32 board with an integrated e-paper driver). The coin acceptor,
MOSFET and button pins are the same on both profiles; only the display SPI and
control pins differ.

.. note::

   The authoritative pin assignments live in ``src/board.rs``. The tables below
   are generated from it — if you ever change a pin in the firmware, update it
   there and re-check these tables.

E-paper display
---------------

Connect the Waveshare e-paper display to the ESP32 using the GPIO for your board
profile:

.. list-table::
   :header-rows: 1
   :widths: 34 33 33

   * - Display pin
     - Generic (GPIO)
     - Waveshare (GPIO)
   * - BUSY
     - 27
     - 25
   * - RST
     - 33
     - 26
   * - DC
     - 25
     - 27
   * - CS
     - 26
     - 15
   * - CLK (SCK)
     - 18
     - 13
   * - DIN (MOSI)
     - 23
     - 14
   * - GND
     - GND
     - GND
   * - 3.3V
     - 3.3V
     - 3.3V

Coin acceptor & MOSFET
----------------------

The MOSFET module lets the firmware block or enable the coin acceptor at the
right moments. These pins are identical on both board profiles.

.. list-table::
   :header-rows: 1
   :widths: 60 40

   * - Signal
     - ESP32 GPIO
   * - Coin acceptor "Coin" pin
     - 17
   * - MOSFET control pin (gate)
     - 16
   * - MOSFET GND pin
     - GND

Wiring notes:

- For the **Coin → GPIO 17** connection, use a cable that is as short as possible.
- Short-circuit the two pins below the switch on the coin acceptor with the
  MOSFET on *GND IN* and *GND OUT*.
- Connect the MOSFET GND pin to the ESP32 GND and the control pin to GPIO 16.

See :doc:`coin-acceptor` for programming the acceptor itself.

LED push button
---------------

The illuminated push button triggers the withdrawal. These pins are identical on
both board profiles.

.. list-table::
   :header-rows: 1
   :widths: 60 40

   * - Signal
     - ESP32 GPIO
   * - Button LED (+)
     - 21
   * - Button LED (−)
     - GND
   * - Button switch pin 1
     - 32
   * - Button switch pin 2
     - GND

For further wiring inspiration, see the
`original Lightning ATM documentation
<https://github.com/21isenough/LightningATM/tree/master/docs>`_.

Reconfiguration button
----------------------

The ESP32's onboard **BOOT button (GPIO 0)** is used to re-enter the
configuration portal — hold it during power-on. It lives on the ESP32 board
inside the enclosure and is not accessible to end users. See
:doc:`../configuration`.