Circuit Documentation

Summary

This circuit is designed to control a CNC machine with stepper motors, a servo motor, and an ESP32-CAM module for capturing images. The Arduino Nano serves as the primary controller, interfacing with stepper motor drivers, limit switches, and a servo motor. The ESP32-CAM module is used for wireless communication and image capture. The circuit includes a microphone for audio input and a digital amplifier for audio output. Power management is handled by a 5V battery connected through a rocker switch.

Component List

A4988 Stepper Motor Driver Carrier

• Description: A compact driver for controlling stepper motors in microstepping mode.
• Pins: ENABLE, MS1, MS2, MS3, RESET, SLEEP, STEP, DIR, GND, VCC, 1B, 1A, 2A, 2B, VMOT

Stepper Motor (Bipolar)

• Description: A bipolar stepper motor for precise motion control.
• Pins: D, B, C, A

ESP32 - CAM

• Description: A small-sized ESP32-based board with camera and Wi-Fi capabilities.
• Pins: 5V, GND, IO12, IO13, IO15, IO14, IO2, IO4, VOT, VOR, VCC, IO0, IO16, 3V3

INMP441 FRONT MIC

• Description: A digital I2S output microphone with high signal-to-noise ratio.
• Pins: L/R, WS, SCK, SD, VDD, GND

Loudspeaker

• Description: An audio output device for sound playback.
• Pins: pin1, pin2

5v Battery

• Description: A power source for the circuit.
• Pins: positive, negative

Rocker Switch

• Description: A switch to control the power supply to the circuit.
• Pins: 1, 2

MAX98375

• Description: A digital audio amplifier with I2S input.
• Pins: LRC, BLCK, DIN, GAIN, SD, GND, VIN

FTDI Programmer

• Description: A USB to serial converter for programming microcontrollers.
• Pins: DTR, RX, TX, VCC, CTS, GND

Limit Switch

• Description: A switch that is actuated by the motion of a machine part or presence of an object.
• Pins: C, NO, NC

Arduino Nano

• Description: A small, complete, and breadboard-friendly board based on the ATmega328.
• Pins: D1/TX, D0/RX, RESET, GND, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11/MOSI, D12/MISO, VIN, 5V, A7, A6, A5, A4, A3, A2, A1, A0, AREF, 3V3, D13/SCK

ESP32 Devkit V1

• Description: A development board with an ESP32 chip for Wi-Fi and Bluetooth applications.
• Pins: 3V3, GND, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, VIN

Servo

• Description: A rotary actuator or linear actuator that allows for precise control of angular or linear position.
• Pins: GND, VCC, PWM

Wiring Details

A4988 Stepper Motor Driver Carrier

• ENABLE: Not connected
• MS1, MS2, MS3: Not connected (for microstepping configuration)
• RESET: Connected to SLEEP
• SLEEP: Connected to RESET
• STEP: Controlled by Arduino Nano (D6 or D8)
• DIR: Controlled by Arduino Nano (D5 or D7)
• GND: Common ground
• VCC: Connected to 5V supply
• 1B, 1A, 2A, 2B: Connected to corresponding stepper motor pins
• VMOT: Not specified (usually connected to motor power supply)

Stepper Motor (Bipolar)

• D, B, C, A: Connected to corresponding A4988 driver pins 1B, 1A, 2A, 2B

ESP32 - CAM

• 5V: Connected to 5V supply
• GND: Common ground
• IO12, IO13, IO15, IO14, IO2, IO4: Not specified
• VOT: Connected to FTDI Programmer RX
• VOR: Connected to FTDI Programmer TX
• VCC: Connected to 5V supply
• IO0, IO16: Not specified
• 3V3: Not specified

INMP441 FRONT MIC

• L/R: Connected to 5V supply
• WS: Connected to ESP32 Devkit V1 D25
• SCK: Connected to ESP32 Devkit V1 D33
• SD: Connected to ESP32 Devkit V1 D32
• VDD: Connected to 5V supply
• GND: Common ground

Loudspeaker

• pin1, pin2: Not specified (usually connected to an audio amplifier output)

5v Battery

• positive: Connected to the rocker switch
• negative: Common ground

Rocker Switch

• 1: Connected to 5V battery positive
• 2: Connected to circuit power input

MAX98375

• LRC: Connected to ESP32 Devkit V1 D14
• BLCK: Connected to ESP32 Devkit V1 D27
• DIN: Connected to ESP32 Devkit V1 D26
• GAIN: Connected to 5V supply
• SD: Not specified
• GND: Common ground
• VIN: Connected to 5V supply

FTDI Programmer

• DTR: Not specified
• RX: Connected to ESP32 - CAM VOT
• TX: Connected to ESP32 - CAM VOR
• VCC: Connected to 5V supply
• CTS: Not specified
• GND: Common ground

Limit Switch

• C: Common ground
• NO: Connected to Arduino Nano D2 or D3
• NC: Not connected

Arduino Nano

• D1/TX: Connected to ESP32 Devkit V1 TX0
• D0/RX: Connected to ESP32 Devkit V1 RX0
• RESET, AREF, 3V3: Not specified
• GND: Common ground
• D2, D3: Connected to limit switches NO
• D5, D6, D7, D8: Control A4988 drivers DIR and STEP
• D9: Connected to Servo PWM
• D10, D11/MOSI, D12/MISO, D13/SCK: Not specified
• VIN, 5V: Connected to 5V supply
• A0-A7: Not specified

ESP32 Devkit V1

• 3V3, EN, VP, VN, D34, D35, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, D22, D23: Not specified
• GND: Common ground
• RX0: Connected to Arduino Nano D0/RX
• TX0: Connected to Arduino Nano D1/TX
• D25, D26, D27, D14, D32, D33: Connected to INMP441 FRONT MIC and MAX98375
• D12, D13: Not specified
• VIN: Connected to 5V supply

Servo

• GND: Common ground
• VCC: Connected to 5V supply
• PWM: Controlled by Arduino Nano D9

Documented Code

ESP32 - CAM Code (sketch.ino)

#include <WebServer.h>
#include <WiFi.h>
#include <esp32cam.h>

const char* WIFI_SSID = "Your SSID";
const char* WIFI_PASS = "Your Password";

WebServer server(80);

static auto loRes = esp32cam::Resolution::find(320, 240);
static auto midRes = esp32cam::Resolution::find(350, 530);
static auto hiRes = esp32cam::Resolution::find(800, 600);

void serveJpg()
{
  auto frame = esp32cam::capture();
  if (frame == nullptr) {
    Serial.println("CAPTURE FAIL");
    server.send(503, "", "");
    return;
  }
  Serial.printf("CAPTURE OK %dx%d %db", frame->getWidth(), frame->getHeight(),
                static_cast<int>(frame->size()));

  server.setContentLength(frame->size());
  server.send(200, "image/jpeg");
  WiFiClient client = server.client();
  frame->writeTo(client);
}

void handleJpgLo()
{