ESP32 Module Schematic
Overview
This tutorial builds a schematic-only ESP32-WROOM style module circuit. It keeps the example focused on the connections that matter before PCB layout:
- a 3.3 V regulator from USB 5 V
- EN reset and IO0 boot strapping
- USB-UART programming connections
- decoupling capacitors near the ESP32 module
- I2C, SPI, UART, power, and ground breakout headers
Use this as a starting point when you want an ESP32 module design that is easier to review before you add the final PCB footprint, antenna keepout, and routing.
Schematic
Pin Groups
| Group | ESP32 pins used in the example | Purpose |
|---|---|---|
| Power | 3V3, GND1, GND2, GND3 | Main ESP32 supply and return pins. |
| Reset | EN | Pulled up to 3.3 V, with a reset button and capacitor to ground. |
| Boot | GPIO0 | Pulled up to 3.3 V, with a boot button to ground for programming mode. |
| USB-UART | U0TXD, U0RXD | Connects the ESP32 serial console and flashing interface to the USB-UART bridge. |
| I2C | GPIO21, GPIO22 | Breaks out the usual SDA and SCL pins for sensors. |
| SPI | GPIO23, GPIO19, GPIO18, GPIO5 | Breaks out MOSI, MISO, SCK, and CS for SPI peripherals. |
Adapting This for a Real PCB
Before turning this schematic into a routed board, confirm the exact ESP32 module variant and its datasheet. The common review points are:
- keep the antenna end of the module clear of copper, components, and ground pour according to the module datasheet
- keep the 10 uF and 100 nF 3.3 V capacitors close to the ESP32 module supply pins
- verify boot strapping pins before adding external pullups, pulldowns, or peripherals
- choose a 3.3 V regulator that can handle Wi-Fi transmit current peaks
- cross TX and RX between the USB-UART bridge and the ESP32 module