ESP12-F Grove Sensor Development Board

Overview

This project is a development board based on the ESP-12F (ESP8266MOD) microcontroller module, designed for use with the Grove - Sound Sensor.
The board accepts a 5 V power input via a Micro USB connector, protected by a fuse and Schottky diode. The voltage is regulated down to 3.3 V using an LD1117V33 LDO regulator, supplying power to the ESP module and peripheral components.

The main purpose of this project is to provide a compact, programmable platform for sound-based applications — such as sound detection, voice-triggered control, or noise level monitoring.

Power Supply and Protection

• Power Input: Micro USB connector (X1) provides 5 V DC to the board.

• Fuse (F1): 750 mA polyfuse for overcurrent protection.

• Diode (D1, 1N5819 Schottky): Prevents reverse current flow and protects the USB source.

• Voltage Regulator (U2, LD1117V33): Converts 5 V input to a stable 3.3 V output for the ESP-12F and related circuitry.

• Capacitors (C1–C6): Used for filtering and voltage stabilization (values from 100 nF to 100 µF).

Main Components

1. ESP-12F (ESP8266MOD)

• Serves as the main microcontroller and Wi-Fi interface.

• Connected to an external FTDI programming header (J1) for USB-to-UART communication.

• GPIO pins (e.g., GPIO0, GPIO2, GPIO15) are configured for boot mode selection and normal operation.

• RESET and FLASH push buttons are provided for programming and system reset.

2. Grove - Sound Sensor

• Connected via a dedicated 4-pin Grove connector (PH-4A type).

• Signal output is fed into the ESP’s ADC input through a voltage divider (R12 = 2 kΩ, R13 = 1 kΩ).

• Allows measurement of sound amplitude as an analog voltage.

Programming and Operation

• FTDI Header (J1): Enables easy programming and serial communication with the ESP module.

  • Pins: TXO, RXI, DTR, CTS, VCC, GND.

  • The DTR signal is routed to EN and GPIO0 to support automatic bootloader mode for flashing firmware.

• Buttons:

  • FLASH – Forces the ESP into programming mode when held during reset.

  • RESET (RST_USER) – Resets the microcontroller.

Technical Specifications