Component Pin Classification

flux

1:56

Searching for datasheet info.

Looking for "List the module's strapping pins or bootstrap pins, including GPIO numbers and any boot mode notes." in esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf

Looking for "List the input-only GPIO pins for ESP32-WROOM-32U, including any restrictions like no internal pullup/pulldown." in esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf

Looking for "List the pins connected to the integrated SPI flash or internal memory on ESP32-WROOM-32U, including GPIO numbers and signal names, and whether they should be reserved." in esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf

From the datasheet for this module, here are the pin groups you asked for:
Bootstrap / strapping pins
These pins are sampled at reset / power-up to select boot-related behavior:
  • GPIO0
    • Boot mode strap
    • 1 = SPI boot
    • 0 with GPIO2 low = download boot
  • GPIO2
    • Boot mode strap
    • Used together with GPIO0 for boot selection
  • GPIO12 (MTDI)
    • Straps the internal VDD_SDIO / LDO voltage
  • GPIO15 (MTDO)
    • Controls U0TXD boot log printing
    • Also participates in SDIO slave timing selection
  • GPIO5
    • Participates in SDIO slave timing selection
Default strap states reported by the datasheet:
  • GPIO0: pull-up
  • GPIO2: pull-down
  • GPIO12 / MTDI: pull-down
  • GPIO15 / MTDO: pull-up
  • GPIO5: pull-up
Input-only pins
These GPIOs are input-only:
  • GPIO34
  • GPIO35
  • GPIO36 (SENSOR_VP)
  • GPIO39 (SENSOR_VN)
Restriction from the datasheet:
  • GPIO34–GPIO39 can only be used as inputs
  • They do not have software-enabled internal pull-up or pull-down resistors
Pins connected to internal module memory / reserved flash interface
These pins are used by the module’s on-board SPI flash and should be treated as reserved:
  • GPIO6 - SCK / CLK
  • GPIO7 - SDO / SD0
  • GPIO8 - SDI / SD1
  • GPIO9 - SHD / SD2
  • GPIO10 - SWP / SD3
  • GPIO11 - SCS / CMD
So the practical “do not use for normal GPIO” list is:
  • GPIO6
  • GPIO7
  • GPIO8
  • GPIO9
  • GPIO10
  • GPIO11
If you want, I can also turn this into a pin-property mapping for your part project, such as:
  • Pin Type
  • Section
  • Pin Group
  • Pin Description
Create pin-property mapping
Mark reserved flash pins
Group input-only pins
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    step

    ESP32-WROOM-32U--3DModel-STEP-269445.STEP

    ESP32-WROOM-32U--3DModel-STEP-2694453D Model
    ESP32-WROOM-32D

    ESP32-WROOM-32D

    ESP32-WROOM-32D Symbol.svgDefault
    ESP32-WROOM-32U-removebg-preview.png

    ESP32-WROOM-32U-removebg-preview.png

    ESP32-WROOM-32U-removebg-previewThumbnail
    kicad_mod

    MODULE_ESP32-WROOM-32U-FS.kicad_mod

    MODULE_ESP32-WROOM-32U-FSFootprint

    ESP32-WROOM-32U

    ESP32-WROOM-32U thumbnail
    Bluetooth, WiFi 802.11b/g/n, Bluetooth v4.2 +EDR, Class 1, 2 and 3 Transceiver Module 2.4GHz ~ 2.5GHz Integrated, Trace Surface Mount #RF #wifi #ESP32 #ESP32WROOM #CommonPartsLibrary #MCU #module

    Properties

    Module

    Espressif Systems

    ESP32-WROOM-32U

    espressif.com/sites/default/files/documentation/esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf

    ESP

    creativecommons.org/licenses/by/4.0/

    parametric-v1

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