Arduino功率计

我想创建一个功率计，并使用arduino记录信息并发送到网络。功率计有什么简单的解决方案吗？我住在阿根廷，电源线是220V。谢谢

您可以检查一下Tweet-a-Watt，看看它是否可以在220V电源线上使用。该项目至少应该给您一个入门的思路。

看一下这些项目：

1. http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1258971285/all
2. http://pwrusage.codeplex.com
3. http://www.cerebralmeltdown.com/programming_projects/Arduino_Kilowatt_Meter/index.html
4. http://www.alexgirard.com/2009/03/05/powermeter-more-info/
5. http://jarv.org/pwrmon.shtml
6. http://openenergymonitor.org/emon/node/58
7. http://openenergymonitor.org/emon/node/27
8. http://openenergymonitor.org/emon/node/79
9. http://www.billporter.info/not-so-tiny-power-meter/

足够？;-)

创建准确的功率计并非易事。您需要一种以足够的精度和速度感测电压和电流的方法，以检测它们之间的相位差（功率因数）并计算有功功率和视在功率。您几乎需要使用DSP。

创建基本的功率计可以通过感应和直流平均电压和电流来完成，而无需考虑无功功率和高速采样的需求。精度将随负载质量的变化而变化。

市场上有专门用于功率计量的IC，例如Microchip MCP3909，您可以将其与Arduino一起使用。

来自Smart Energy Groups的此系统可能很有趣，它基于Arduino硬件等。

您可以将HALL效果传感器（可能是10-30e？）与Arduino开发板一起使用。

我一直在广泛使用ESP8266（带有Arduino IDE）以及各种ADC和专用的能源监控DSP（ATM90E26和ADE7763）来构建网络连接的能源监控器。

基本ADC + Wifi启用Arduino兼容NodeMCU的Fritzing图如下所示：

上面说明了使用ESP8266能源监控器的代码。请注意，这是一种低精度的方法，很容易实现使用变压器对电压和CT电流进行采样的解决方案。更高精度的解决方案需要直接采样240V（使用分压器阶梯和分流电阻器），并需要考虑其他设计因素，以处理高压工作引起的问题。

/*


*  This sketch sends ads1115 current sensor data via HTTP POST request to thingspeak server.
 *  It needs the following libraries to work (besides the esp8266 standard libraries supplied with the IDE):
 *
 *  - https://github.com/adafruit/Adafruit_ADS1X15
 *
 *  designed to run directly on esp8266-01 module, to where it can be uploaded using this marvelous piece of software:
 *
 *  https://github.com/esp8266/Arduino
 *
 *  2015 Tisham Dhar
 *  licensed under GNU GPL
 */

#include <ESP8266WiFi.h>
#include <Wire.h>
#include <Adafruit_ADS1015.h>

// replace with your channel's thingspeak API key, 
String apiKey = "XXXXXXXXXXXXX";
//WIFI credentials go here
const char* ssid     = "XXXXXXXXXXX";
const char* password = "XXXXXXXXXXXXXXXXXXXXX";
Adafruit_ADS1115 ads;  /* Use this for the 16-bit version */

const char* server = "api.thingspeak.com";
WiFiClient client;

double offsetI;
double filteredI;
double sqI,sumI;
int16_t sampleI;
double Irms;

double squareRoot(double fg)  
{
  double n = fg / 2.0;
  double lstX = 0.0;
  while (n != lstX)
  {
    lstX = n;
    n = (n + fg / n) / 2.0;
  }
  return n;
}

double calcIrms(unsigned int Number_of_Samples)
{
  /* Be sure to update this value based on the IC and the gain settings! */
  float multiplier = 0.125F;    /* ADS1115 @ +/- 4.096V gain (16-bit results) */
  for (unsigned int n = 0; n < Number_of_Samples; n++)
  {
    sampleI = ads.readADC_Differential_0_1();

    // Digital low pass filter extracts the 2.5 V or 1.65 V dc offset, 
  //  then subtract this - signal is now centered on 0 counts.
    offsetI = (offsetI + (sampleI-offsetI)/1024);
    filteredI = sampleI - offsetI;
    //filteredI = sampleI * multiplier;

    // Root-mean-square method current
    // 1) square current values
    sqI = filteredI * filteredI;
    // 2) sum 
    sumI += sqI;
  }

  Irms = squareRoot(sumI / Number_of_Samples)*multiplier; 

  //Reset accumulators
  sumI = 0;
//--------------------------------------------------------------------------------------       

  return Irms;
}

void setup() {
  Serial.begin(115200);
  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  ads.setGain(GAIN_ONE);        // 1x gain   +/- 4.096V  1 bit = 2mV      0.125mV
  ads.begin();
}

void loop() {


  //Serial.print("Differential: "); Serial.print(results); Serial.print("("); Serial.print(trans_volt); Serial.println("mV)");
  double current = calcIrms(2048);

  if (client.connect(server,80)) {  //   "184.106.153.149" or api.thingspeak.com
    String postStr = apiKey;
           postStr +="&field1=";
           postStr += String(current);
           postStr += "\r\n\r\n";

     client.print("POST /update HTTP/1.1\n"); 
     client.print("Host: api.thingspeak.com\n"); 
     client.print("Connection: close\n"); 
     client.print("X-THINGSPEAKAPIKEY: "+apiKey+"\n"); 
     client.print("Content-Type: application/x-www-form-urlencoded\n"); 
     client.print("Content-Length: "); 
     client.print(postStr.length()); 
     client.print("\n\n"); 
     client.print(postStr);  
  }
  client.stop();

  //Serial.println("Waiting...");    
  // thingspeak needs minimum 15 sec delay between updates
  delay(20000);  
}