ESP32 How to use an ESP32 with devices

1 x ESP32 monitor/controller

3.3V ESP32 logic and development board ($7.38)

See pin outs below

ESP32 Projects
How to set up an ESP32 as a basic HTTP Restful API for standalone use
How to use an EPS32 to measure current with a micro CT for multiple circuits Useful for home automation in wiring closets circuit monitoring
Magic Fire Alarm project Special fully configurable quick detection of fires or frost with individual thresholds Individually or combined reporting
How to connect 1-Wire devices [Section coming soon]
How to measure temperature with a PT1000 sensor [Section coming soon]
How to measure voltage of a battery [Section coming soon]
ESP32 C3 Super mini Projects
How to set up an ESP32 C3 Super mini to run on battery and check a door switch and report [low cost]

ESP32D Pin mapping
(click table for installable program guide code)

Left side pins (from top to bottom)

| Label | GPIO Number   | Notes
| ----- | ------------- | -------------------
| EN    | Reset pin     | Not GPIO
| VP    | GPIO36        | Input-only (ADC)
| VN    | GPIO39        | Input-only (ADC)
| D34   | GPIO34        | Input-only (ADC)
| D35   | GPIO35        | Input-only (ADC)
| D32   | GPIO32        | ADC, can be input
| D33   | GPIO33        | ADC, can be input
| D25   | GPIO25        | DAC, can be output
| D26   | GPIO26        | DAC, can be output
| D27   | GPIO27        | ADC, can be input
| D14   | GPIO14        | PWM, SPI, I2C
| D12   | GPIO12        | PWM, SPI, I2C
| D13   | GPIO13        | PWM, SPI, I2C
| GND   | Ground        | Ground pin
| VIN   | Input voltage | Power in 5V in/out
|       |               | out =< 500 ma

Right side pins (from top to bottom)

| Label | GPIO Number   | Notes
| ----- | ------------- | ---------------
| D23   | GPIO23        | PWM, SPI
| D22   | GPIO22        | PWM, SPI, I2C
| TXD   | GPIO1         | UART0 TX
| RXD   | GPIO3         | UART0 RX
| D21   | GPIO21        | PWM, I2C
| D19   | GPIO19        | PWM, SPI
| D18   | GPIO18        | PWM, SPI
| D5    | GPIO5         | PWM, SPI
| TX2   | GPIO17        | UART2 TX
| RX2   | GPIO16        | UART2 RX
| D4    | GPIO4         | PWM, SPI
| D2    | GPIO2         | Built-in LED, some
| D15   | GPIO15        | PWM, SPI
| GND   | Ground        | Ground pin
| 3V3   | 3.3V Power    | Power pin max 300ma

Notes:

    Pins VP (GPIO36), VN (GPIO39), D34 (GPIO34), D35 (GPIO35), D32, and D33 are ADC-capable input-only pins.
    They cannot be used as digital outputs.

    Pins like D25 and D26 have DAC (digital-to-analog converter) capability.

    Pins labelled TXD/RXD correspond to the UART serial pins.

    Pins like D2 (GPIO2) often have an onboard LED on some ESP32 boards.

    EN is not a GPIO pin; it's the enable (reset) pin.

Summary usage:

    Use the GPIO numbers in code, e.g., digitalRead(34) or digitalWrite(2, HIGH).

    Do not to use input-only ADC pins as outputs.

    You can use most of the pins for PWM, SPI, I2C, UART, or digital IO as shown.

    max GPIO output 12 ma per pin, Use resistors when driving LEDs (eg. 220-330 Ohms). max total 120 ma

    Input consumption ~50 µA typical

    No pin tolerates < 0 V or > 3.6 V