+---------------------------------------------------------------------------------------------------------------+
|  WeMos D1 Mini  ---  rc522                                                                                    |
+---------------------------------------------------------------------------------------------------------------+
|  Rails: 5V, 3V3, GND                                                                                          |
|                                                                                                               |
|  reader  [NXP MFRC522 RFID reader (SPI)]  -- RFID Reader                                                      |
|    VCC   -> rail 3V3                                                                                          |
|    GND   -> rail GND                                                                                          |
|    SCK   -> spi0 (D5)                                                                                         |
|    MISO  -> spi0 (D6)                                                                                         |
|    MOSI  -> spi0 (D7)                                                                                         |
|    CS    -> D8                                                                                                |
|    RESET -> D4                                                                                                |
|                                                                                                               |
|  activity_led  [WS2812B addressable LED (NeoPixel)]  -- RC522 Reader LED                                      |
|    VCC   -> rail 5V                                                                                           |
|    GND   -> rail GND                                                                                          |
|    DIN   -> D3                                                                                                |
|                                                                                                               |
|  rfid_button  [Generic GPIO binary sensor]  -- RC522 Reader Button                                            |
|    IN    -> D1                                                                                                |
|                                                                                                               |
|  Passives:                                                                                                    |
|    c1: 100nF capacitor, reader.VCC  <->  GND   (decoupling reader)                                            |
|    c2: 100nF capacitor, activity_led.VCC  <->  GND   (decoupling neopixel)                                    |
|                                                                                                               |
|  BOM:                                                                                                         |
|    - WeMos D1 Mini                                                                                            |
|    - NXP MFRC522 RFID reader (SPI)  (reader)                                                                  |
|    - WS2812B addressable LED (NeoPixel)  (activity_led)                                                       |
|    - Generic GPIO binary sensor  (rfid_button)                                                                |
|    - 2x 100nF capacitor                                                                                       |
|                                                                                                               |
|  Power: ~33mA typical, ~86mA peak (budget 500mA)  OK                                                          |
|                                                                                                               |
|  Warnings:                                                                                                    |
|    [info] buzzer_in_extras: Piezo buzzer (esp8266_pwm output) and RTTTL block live in esphome_extras until a  |
|                             buzzer/rtttl library entry lands.                                                 |
+---------------------------------------------------------------------------------------------------------------+
