esp32 arduino platformio adc

ESP32 Arduino平台是一个基于ArduinoIDE的扩展板，特别适用于ESP32系列芯片，它提供了对硬件加速的模拟数字转换器（ADC）的支持。ESP32的ADC有12位分辨率，总共32个通道，可以用来采集模拟信号，并将其转化为数字值。

在PlatformIO环境中使用ESP32进行ADC操作，你需要首先设置适当的库，比如`Adafruit ESP32 FeatherWing`或`ESP32-Servo-Shield`等，它们包含了处理ADC功能的相关函数。基本步骤包括：

1. **导入库**：在Arduino IDE中，点击Sketch -> Include Library -> Manage Libraries，搜索并安装包含ADC支持的ESP32库。

2. **初始化ADC**：通常，在setup()函数里初始化ADC模块，例如：

#include <ESP32_Adafruit_ADC.h>
Adafruit_esp32_adc adc;
void setup() {
    adc.begin();
}

3. **读取ADC值**：通过指定ADC通道获取模拟输入，如：

int reading = adc.readADC(0); // 0-31是ADC通道编号

4. **处理数据**：将读取到的数字值进行相应的处理，如电压计算、信号分析等。

相关问题

基于ESP32开发板用PlatformIO编写包含音乐fft频谱显示/温湿度表/WiFi时钟功能的文件

以下是基于ESP32开发板使用PlatformIO编写包含音乐fft频谱显示/温湿度表/WiFi时钟功能的文件的示例代码：

#include <Arduino.h>
#include <WiFi.h>
#include <WiFiUdp.h>
#include <Adafruit_Sensor.h>
#include <DHT.h>
#include <Adafruit_NeoPixel.h>
#include <FastLED.h>
#include <ESPAsyncWebServer.h>
#include <WebSocketsServer.h>
#include <WiFiManager.h>
#include <WiFi.h>
#include "esp_wifi.h"
#include "esp_wifi_types.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include <Ticker.h>
#include <esp32-hal-ledc.h>
#include <driver/i2s.h>
#include <driver/adc.h>
#include "esp_adc_cal.h"

#define DHTPIN 15
#define DHTTYPE DHT22

#define LED_PIN 19
#define LED_COUNT 16
#define LED_TYPE WS2812B
#define COLOR_ORDER GRB

#define I2S_BCK 26
#define I2S_WS 25
#define I2S_SD 22
#define I2S_NUM I2S_NUM_0

#define ADC_EN 14
#define ADC_PIN 34
#define ADC_ATTENUATION ADC_ATTEN_DB_11
#define ADC_WIDTH ADC_WIDTH_BIT_12

#define FFT_N 256

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

DHT dht(DHTPIN, DHTTYPE);
Adafruit_NeoPixel strip(LED_COUNT, LED_PIN, LED_TYPE);
WebSocketsServer webSocket = WebSocketsServer(81);
AsyncWebServer server(80);

Ticker clockTicker;
Ticker ledTicker;

float temperature = 0.0;
float humidity = 0.0;

unsigned long lastMillis = 0;
unsigned long lastLedMillis = 0;
unsigned long lastClockMillis = 0;

uint16_t spectrumValues[FFT_N / 2];

void clockTick() {
  lastClockMillis = millis();
}

void ledTick() {
  strip.show();
  FastLED.show();
}

void wifiSetup() {
  WiFiManager wifiManager;
  wifiManager.autoConnect("AutoConnectAP");
  Serial.println("Connected to WiFi!");
}

void webSocketEvent(uint8_t num, WStype_t type, uint8_t * payload, size_t length) {
  switch(type) {
    case WStype_DISCONNECTED:
      Serial.printf("[%u] Disconnected!\n", num);
      break;
    case WStype_CONNECTED: {
      IPAddress ip = webSocket.remoteIP(num);
      Serial.printf("[%u] Connected from %d.%d.%d.%d url: %s\n", num, ip[0], ip[1], ip[2], ip[3], payload);
      String message = "Connected to WebSocket server at IP address ";
      message += ip.toString();
      webSocket.sendTXT(num, message);
      break;
    }
  }
}

void handleRoot(AsyncWebServerRequest *request) {
  request->send(200, "text/plain", "Hello World!");
}

void handleNotFound(AsyncWebServerRequest *request) {
  request->send(404, "text/plain", "Not found");
}

void i2sSetup() {
  i2s_config_t i2sConfig = {
    .mode = i2s_mode_t(I2S_MODE_MASTER | I2S_MODE_RX),
    .sample_rate = 44100,
    .bits_per_sample = i2s_bits_per_sample_t(32),
    .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
    .communication_format = i2s_comm_format_t(I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_MSB),
    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count = 8,
    .dma_buf_len = 64
  };
  i2s_pin_config_t pinConfig = {
    .bck_io_num = I2S_BCK,
    .ws_io_num = I2S_WS,
    .data_out_num = -1,
    .data_in_num = I2S_SD
  };
  i2s_driver_install(I2S_NUM, &i2sConfig, 0, NULL);
  i2s_set_pin(I2S_NUM, &pinConfig);
}

void adcSetup() {
  adc1_config_width(ADC_WIDTH);
  adc1_config_channel_atten(ADC1_CHANNEL_6, ADC_ATTENUATION);
}

void setup() {
  Serial.begin(115200);

  wifiSetup();

  dht.begin();

  strip.begin();
  strip.setBrightness(255);
  strip.show();

  FastLED.addLeds<LED_TYPE, LED_PIN, COLOR_ORDER>(strip.leds(), strip.numPixels());

  i2sSetup();

  adcSetup();

  server.on("/", HTTP_GET, handleRoot);
  server.onNotFound(handleNotFound);
  server.begin();

  webSocket.begin();
  webSocket.onEvent(webSocketEvent);

  clockTicker.attach(1, clockTick);
  ledTicker.attach(50, ledTick);
}

void loop() {
  webSocket.loop();

  if (millis() - lastMillis > 1000) {
    temperature = dht.readTemperature();
    humidity = dht.readHumidity();

    Serial.print("Temperature: ");
    Serial.println(temperature);
    Serial.print("Humidity: ");
    Serial.println(humidity);

    lastMillis = millis();
  }

  if (millis() - lastLedMillis > 20) {
    int i = 0;
    int16_t samples[FFT_N];
    uint32_t adcValue = 0;
    for (i = 0; i < FFT_N; i++) {
      i2s_pop_sample(I2S_NUM, (char *)&adcValue, portMAX_DELAY);
      samples[i] = (int16_t)(adcValue << 16 >> 16);
    }
    fft(samples, spectrumValues, FFT_N);
    for (i = 0; i < LED_COUNT; i++) {
      uint16_t value = spectrumValues[i * (FFT_N / LED_COUNT)];
      int red = map(value, 0, 5000, 0, 255);
      int green = map(value, 0, 5000, 0, 255);
      int blue = map(value, 0, 5000, 0, 255);
      strip.setPixelColor(i, strip.Color(red, green, blue));
    }
    lastLedMillis = millis();
  }
}

该代码文件包含了温湿度传感器、WS2812B LED灯带、I2S音频输入和WebSocket服务器的代码。它还使用了FastLED库和ESP32库的FFT函数来计算音频频谱，并使用WiFiManager库来连接WiFi网络。此外，还包括了一个定时器用于更新时钟，并使用了AsyncWebServer库和WebSocketsServer库来创建一个服务器和一个WebSocket服务器，用于通过WebSockets发送数据。