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Topic: TDS Meter cannot working with Ethernet (Read 110 times) previous topic - next topic


Hi guys, i want to build mini hydroponic system with IoT using Arduino Uno. I try to use TDS Meter module and Ethernet shield module together. If they are running separately, everything is fine, but when i put them together, the TDS Meter module keep showing 0ppm.

Can anybody help me?

#include <SPI.h>
#include <Ethernet.h>

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };

// if you don't want to use DNS (and reduce your sketch size)
// use the numeric IP instead of the name for the server:
//IPAddress server(74,125,232,128);  // numeric IP for Google (no DNS)
char server[] = "base_url";    // name address for Google (using DNS)

// Set the static IP address to use if the DHCP fails to assign
IPAddress ip(192, 168, 0, 177);
IPAddress myDns(192, 168, 0, 1);

// Initialize the Ethernet client library
// with the IP address and port of the server
// that you want to connect to (port 80 is default for HTTP):
EthernetClient client;

#define TdsSensorPin A2
#define VREF 5.0      // analog reference voltage(Volt) of the ADC
#define SCOUNT  30           // sum of sample point
int analogBuffer[SCOUNT];    // store the analog value in the array, read from ADC
int analogBufferTemp[SCOUNT];
int analogBufferIndex = 0,copyIndex = 0;
float averageVoltage = 0,tdsValue = 0,temperature = 25;

// Variables to measure the speed
unsigned long beginMicros, endMicros;
unsigned long byteCount = 0;
bool printWebData = true;  // set to false for better speed measurement

void setup() {
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only

  // start the Ethernet connection:
  Serial.println("Initialize Ethernet with DHCP:");
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // Check for Ethernet hardware present
    if (Ethernet.hardwareStatus() == EthernetNoHardware) {
      Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
      while (true) {
        delay(1); // do nothing, no point running without Ethernet hardware
    if (Ethernet.linkStatus() == LinkOFF) {
      Serial.println("Ethernet cable is not connected.");
    // try to congifure using IP address instead of DHCP:
    Ethernet.begin(mac, ip, myDns);
  } else {
    Serial.print("  DHCP assigned IP ");
  // give the Ethernet shield a second to initialize:
  Serial.print("connecting to ");

  // if you get a connection, report back via serial:
  beginMicros = micros();

void loop() {

  if (client.connect(server, 80)) {   
    Serial.print("connected to ");
    // Make a HTTP request:
    client.print("GET /hydrophonic/plant.php?wl=");
    client.println(" HTTP/1.1");
    client.println("Host: www.telebot.stg02.mobileforce.mobi");
    client.println("Connection: close");
  } else {
    // if you didn't get a connection to the server:
    Serial.println("connection failed");
  Serial.print("time spend ");


void tdsEc(){
  //Menghitung TDS/EC
    static unsigned long analogSampleTimepoint = millis();
   if(millis()-analogSampleTimepoint > 40U)     //every 40 milliseconds,read the analog value from the ADC
     analogSampleTimepoint = millis();
     analogBuffer[analogBufferIndex] = analogRead(TdsSensorPin);    //read the analog value and store into the buffer
     if(analogBufferIndex == SCOUNT)
         analogBufferIndex = 0;
   static unsigned long printTimepoint = millis();
   if(millis()-printTimepoint > 800U)
      printTimepoint = millis();
        analogBufferTemp[copyIndex]= analogBuffer[copyIndex];
      averageVoltage = getMedianNum(analogBufferTemp,SCOUNT) * (float)VREF / 1024.0; // read the analog value more stable by the median filtering algorithm, and convert to voltage value
      float compensationCoefficient=1.0+0.02*(temperature-25.0);    //temperature compensation formula: fFinalResult(25^C) = fFinalResult(current)/(1.0+0.02*(fTP-25.0));
      float compensationVolatge=averageVoltage/compensationCoefficient;  //temperature compensation
      tdsValue=(133.42*compensationVolatge*compensationVolatge*compensationVolatge - 255.86*compensationVolatge*compensationVolatge + 857.39*compensationVolatge)*0.5; //convert voltage value to tds value
      //Serial.print("V   ");
      Serial.print("TDS Value:");

int getMedianNum(int bArray[], int iFilterLen)
      int bTab[iFilterLen];
      for (byte i = 0; i<iFilterLen; i++)
      bTab = bArray;
      int i, j, bTemp;
      for (j = 0; j < iFilterLen - 1; j++)
      for (i = 0; i < iFilterLen - j - 1; i++)
        if (bTab > bTab[i + 1])
        bTemp = bTab;
            bTab = bTab[i + 1];
        bTab[i + 1] = bTemp;
      if ((iFilterLen & 1) > 0)
    bTemp = bTab[(iFilterLen - 1) / 2];
    bTemp = (bTab[iFilterLen / 2] + bTab[iFilterLen / 2 - 1]) / 2;
      return bTemp;

void _delay(float miliseconds)
  timeCounter += miliseconds;


Aug 01, 2020, 04:07 pm Last Edit: Aug 01, 2020, 04:14 pm by ballscrewbob
You can help yourself a lot by reading the following links instead of posting in the first section you came across which was COVID related !

Your topic was Moved  to it's current location / section as it is more suitable.

Could you also take a few moments to Learn How To Use The Forum.
Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum in the future.

It may not be the answer you were looking for but its the one I am giving based on either experience, educated guess, google (who would have thunk it ! ) or the fact that you gave nothing to go with in the first place so I used my wonky crystal ball.

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