ESP8266 Community Forum

- Mon Jun 15, 2015 9:27 pm #20544 I'm trying to make a user interface that allows 8 neopixels to be be controlled through the NodeMCU board. I have three sliders (type='range') used to set the color. The problem I have is when the user sets the sliders and clicks the submit button, the sliders go back to their default position.

The red slider goes from 1 to 100. It the user sets the value to 25, I'd like the slider to come back at 25 when the page reloads. The “value” property sets the location of the slider wiper in the range control. The “redTemp” variable is an integer and stores the location of the red slider. Setting value=redTemp does not seem to work. How can I get page reload to keep the set value of the red slider? (If I set value=65, then the slider is set to position 65 when the page loads)

I'm using arduino 1.6.4 with a NodeMCU board. I started with this great garage door example:
http://www.esp8266.com/viewtopic.php?p=16302

This is the relevant line of the code:

Code: Select all  client.println("<form method=get><br>Red:  <input type='range' min='1' max='100' name=redVal value=redTemp oninput='showValue(this.value)'>");    //was onchange event


Here is all of the code:

Code: Select all//NOTE:  Opening the Serial Monitor tool in Arduino 1.6.4 causes the ESP8266 to reset

#include <ESP8266WiFi.h>
#include <NeoPixelBus.h>

#define pixelCount 8

NeoPixelBus strip = NeoPixelBus(pixelCount, 5);  //D10(TX) on the nodemcu board is 1, D2 is pin 4

int openClosePin = 5;
int statusPin = 4;


WiFiServer server(80);

//*-- IoT Information
const char* SSID = "garage_door";
const char* PASS = "123456789";
int redVal;
int redTemp=1;
int greVal;
int bluVal;
int mattradVal;
char colorBuff[4];
int ledState = LOW;             // ledState used to set the LED
unsigned long previousMillis = 0;        // will store last time LED was updated
const long interval = 300;           // interval at which to blink (milliseconds)
int intCyclopsLedCnt=1;

void setup() {
    Serial.begin(115200);  //NOTE:  this must be done after "strip.Begin()" or Serial Monitor will crash the ESP8266
    delay(50);
    Serial.println();
    Serial.println();
    Serial.print("starting up and connecting to: ");
    Serial.println(SSID);   
    WiFi.softAP(SSID, PASS);  //start the ESP8266 as an Access point
    Serial.println("WiFi connected");
    delay(1000);
    server.begin();  //Start the web server
    Serial.println("Server started");

    strip.Begin();  //this resets all the neopixels to an off state, NOTE: this must be done before serial.begin or "serial monitor" will crash the ESP8266
    strip.Show();
    delay(1000);
}

void loop() {
  int bufLength;

//  strip.SetPixelColor(1,RgbColor(44,55,0));
//  strip.Show();
  delay(500);
 
  if(mattradVal==1)
  {
    cyclopsIt();
  }
  if(mattradVal==2)
  {
    twinkleIt();
  }
 
  WiFiClient client = server.available();    // Check if a client has connected
  if (!client) {
    return;  //do nothing if there is not a client for the server
  }
   
  // Wait until the client sends some data
  Serial.println("new client");
  while(!client.available()){
    delay(1);
  }
   
  // Read the first line of the request
  String request = client.readStringUntil('\r');
  Serial.println("Request is:");
  Serial.println(request);
  client.flush();

  if(request.indexOf("submit") != -1) {  //this is used to ignore "favicon.ico" and other requests
     int Pos_r = request.indexOf("redVal");
     int Pos_g = request.indexOf("greVal", Pos_r);  //finds a location of a string "g", after the position of "r"
     int Pos_b = request.indexOf("bluVal", Pos_g);
     int Pos_rad = request.indexOf("matrad",Pos_b);
     int End = request.indexOf("H", Pos_b);
     if(End < 0){
       End =  request.length() + 1;
     }
     //red
     bufLength = ((Pos_g) - (Pos_r+7));    //the 7 is for the "redVal=" string
     if(bufLength > 4){  //dont overflow the buffer  (we only want 3 digits)
       bufLength = 4;
     }   
     request.substring((Pos_r+7), (Pos_g-1)).toCharArray(colorBuff, bufLength);  //transfer substring to buffer  (cuts from past the "r=" to just before the "g", stores the length into a buffer)
     redVal = atoi(colorBuff);  //converts the array (3 digits) into an interger, this will be the red value
     //Green
     bufLength = ((Pos_b) - (Pos_g+7));    //the 7 is for the "greVal=" string
     if(bufLength > 4){  //dont overflow the buffer
       bufLength = 4;
     }     
     request.substring((Pos_g+7), (Pos_b-1)).toCharArray(colorBuff, bufLength);  //transfer substring to buffer
     greVal = atoi(colorBuff);
     //blue
     bufLength = ((Pos_rad) - (Pos_b+7));  //start to get the blue value
     if(bufLength > 4){  //dont overflow the buffer
       bufLength = 4;
     }     
     request.substring((Pos_b+7), (Pos_rad-1)).toCharArray(colorBuff, bufLength);  //transfer substring to buffer
     bluVal = atoi(colorBuff);



     bufLength = ((End) - (Pos_rad+7));
     if(bufLength > 4){  //dont overflow the buffer
       bufLength = 4;
     }     
     request.substring((Pos_rad+7), (End-1)).toCharArray(colorBuff, bufLength);  //transfer substring to buffer
     mattradVal = atoi(colorBuff);
   
     
    Serial.println("Red is:  ");
    Serial.println(redVal);
    redTemp=redVal;
    Serial.println("Green is:  ");
    Serial.println(greVal);
    Serial.println("Blue is:  ");
    Serial.println(bluVal);
    Serial.println("radio button is:  ");
//    Serial.println(mattradVal);
     strip.SetPixelColor(0,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(1,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(2,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(3,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(4,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(5,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(6,RgbColor(redVal,greVal,bluVal));
     strip.SetPixelColor(7,RgbColor(redVal,greVal,bluVal));
     strip.Show();
  }

  // Return the response
  client.println("HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n");
  client.println("<!DOCTYPE HTML>\r\n<html>\r\n<head>\r\n<title>Matt's test page</title>");
  client.println("<meta name='viewport' content='width=device-width', initial-scale='1'>");
  client.println("<br>");
  client.println("<body><center>Set the color and then choose an animation:");
  client.println("<form method=get><br>Red:  <input type='range' min='1' max='100' name=redVal value=redTemp oninput='showValue(this.value)'>");    //was onchange event
  client.println("<span id='range'>0</span>");
  client.println("<script type='text/javascript'>\r\nfunction showValue(newValue)\r\n{\r\ndocument.getElementById('range').innerHTML=newValue;\r\n}\r\n</script>\r\n");
/*
  client.println("<script type='text/javascript'>");
  client.println("function showValue(newValue)");
  client.println("{");
  client.println("document.getElementById('range').innerHTML=newValue;");
  client.println("}");
  client.println("</script>");
 */
  client.print("<br><br>Green:  <input type='range' min='1' max='100' name=greVal value=>");
  client.print("<br><br>Blue:  <input type='range' min='1' max='100' name=bluVal value=>");
  client.print("<br><br><input type=radio name='matrad' value='1' checked>Cyclopse</>");
  client.print("<input type=radio name='matrad' value='2'>Twinkle</>");
  client.print("<input type=radio name='matrad' value='3'>Solid On</>");
  client.println("&nbsp;<br><br><input name=H type=submit value=submit><br><br>");  //</form>
  client.println("</form>");
  client.println("<script type='text/javascript'></script>\r\n");
  client.println("</center>");
  client.println("</BODY>");
  client.println("</HTML>");
  delay(1);
  Serial.println("Client disconnected");
  Serial.println("");
 
}

void blinkIt(void)
{
  unsigned long currentMillis = millis();
 
  if(currentMillis - previousMillis >= interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;   

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW)
    {
      ledState = HIGH;
     strip.SetPixelColor(0,RgbColor(255,30,30));
     strip.SetPixelColor(1,RgbColor(255,30,30));
    }
    else
    {
      ledState = LOW;
     strip.SetPixelColor(0,RgbColor(5,30,250));
     strip.SetPixelColor(1,RgbColor(5,30,250));
    }
    strip.Show();
  }
}

void cyclopsIt(void)
{
  unsigned long currentMillis = millis();
   
  if(currentMillis - previousMillis >= interval)
  {
    // save the last time you blinked the LED
    previousMillis = currentMillis;   
   
    intCyclopsLedCnt=intCyclopsLedCnt+1;  //advance to the next LED
    if(intCyclopsLedCnt>15)  //There are 8, RGB LED's, this cycles through the 8 going one direction and then 8 going the other direction
    {
      intCyclopsLedCnt=0; //start the LED cyclops over again
    }     
    if(intCyclopsLedCnt <= 7)  //are we going from left to right in lighting up the LED's?
    {
      strip.SetPixelColor(intCyclopsLedCnt,RgbColor(redVal,greVal,bluVal));   //turn on the current LED, based on the 3 slider color
      if(intCyclopsLedCnt>0)  //make sure we haave advanced by one LED before we turn off the previous LED
      {
        strip.SetPixelColor(intCyclopsLedCnt-1,RgbColor(0,0,0));   //turn off the previous LED
      }
    }
    if(intCyclopsLedCnt > 7)  //are we advancing from right to left?
    {
      strip.SetPixelColor(15-intCyclopsLedCnt,RgbColor(100,10,10));   //when going in this direction, always be red
      strip.SetPixelColor(16-intCyclopsLedCnt,RgbColor(0,0,0));   //turn off the previous LED
    }
    strip.Show();  //update the neopixels (WS2812 RGB LED's)
  }
}

void twinkleIt(void)
{
  unsigned long currentMillis = millis();
   
  if(currentMillis - previousMillis >= interval)
  {
      // save the last time you blinked the LED
      previousMillis = currentMillis;   
     
     
  } 
 
}



- Tue Jun 16, 2015 4:09 pm #20628 How about a default value in the program
int defaultSlider = 0;

When page loads read default and change slider
When page closes read slider and change default
Now you just need somewhere to keep default when the thing is turned off. Thats the hard part
Maybe it can be stored on the chip somehow . Its got plenty of memory
I saw this elsewhere and wondered if thats how its done

Code: Select allstruct.pack('<IIII', size, 0x200, ESPROM.ESP_FLASH_BLOCK, offset))[1] != "\0\0":

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG

- Wed Jun 17, 2015 7:57 am #20690 I was trying to use a variable inside of a literal expression. (i.e. inside the quotes on the client.printline statement)
What I had to do was take the variable name "redTemp" (which holds the value of the red siider) out of the quotation marks.

This is what worked for me:

Code: Select all  client.print("<form method=get><br><font size='6'>Red:  </font></h1><input type='range' min='1' max='100' name=redVal value=");
  client.print(redTemp);  //set the value of the slider based upon the previous page load value
  client.println(" style='height:30px; width:200px' oninput='showRedValue(this.value)'>");    //was onchange event
  client.print("<span id='redrange'>");
  client.print(redTemp);  //set the javascript initial value
  client.println("</span>");
  client.println("<script type='text/javascript'>\r\nfunction showRedValue(newValue)\r\n{\r\ndocument.getElementById('redrange').innerHTML=newValue;\r\n}\r\n</script>\r\n");

- Thu Aug 20, 2015 5:10 pm #26627 Thanks! This post helped me to make a similar page:)
This code displays the values for all the three sliders.
You can change rangeX to be the actual value, the first time it loads the page.

Code: Select all//first slider
      client.print("<form method=get><br>Red:  <input type='range' min='1' max='100' name=redVal value=redTemp oninput='showValue(this.value)'>");
      client.println("<span id='range'>0</span>");
      client.println("<script type='text/javascript'>\r\nfunction showValue(newValue)\r\n{\r\ndocument.getElementById('range').innerHTML=newValue;\r\n}\r\n</script>\r\n");

      //second slider
      client.print("<br><br>Green:  <input type='range' min='1' max='100' name=greVal value=greTemp oninput='showValue1(this.value)'>");
      client.println("<span id='range1'>0</span>");
      client.println("<script type='text/javascript'>\r\nfunction showValue1(newValue)\r\n{\r\ndocument.getElementById('range1').innerHTML=newValue;\r\n}\r\n</script>\r\n");
     
      //third slider
      client.print("<br><br>Blue:  <input type='range' min='1' max='100' name=bluVal value=bluTemp oninput='showValue2(this.value)'>");
      client.println("<span id='range2'>0</span>");
      client.println("<script type='text/javascript'>\r\nfunction showValue2(newValue)\r\n{\r\ndocument.getElementById('range2').innerHTML=newValue;\r\n}\r\n</script>\r\n");