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I have a google gauge that shows my PM2.5 sensor values but I would like to make 3 gauges appear side by side that show the value of different sensors. How can I do that? Thanks

Hello everyone, I am new to ThingSpeak and ESP32, I would like to send IMU sensor acceleration data from my ESP32 to ThingSpeak so that I can use this data for further analysis. I have tried the example code provided in this link: Bulk-Update and this works perfectly fine for me with the default update interval and post interval. I also attached the code here.

#include <Wire.h>
#include <Arduino.h>
#include <Adafruit_MCP4725.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BNO055.h>
#include <utility/imumaths.h>
#include <WiFi.h>
#include "ThingSpeak.h"

// Define multiplexer address
#define TCAADDR 0x70

// Define imu and dac objects
Adafruit_BNO055 bno = Adafruit_BNO055(55, 0x28);

char jsonBuffer[500] = "[";

char ssid[] = "my ssid";
char pass[] = "my password";
WiFiClient client;

char server[] = "api.thingspeak.com";

unsigned long lastConnectionTime = 0;
unsigned long lastUpdateTime = 0;
const unsigned long postingInterval = 15L * 1000L;
const unsigned long updateInterval = 3L * 100L;

// To choose the multiplexer specific channel (between 0 and 7)
void tcaselect(uint8_t i){
  if (i > 7) return;

Wire.beginTransmission(TCAADDR);
Wire.write(1 << i);
Wire.endTransmission();
}

    void setup() {
      // put your setup code here, to run once:
  Wire.begin();
  Serial.begin(9600);
  while(!Serial);
  delay(1000);
  Serial.println("Serial communication set up");

// set up bno055
tcaselect(2);
if (!bno.begin()){
  Serial.println("Failed to connect to BNO055");
  while (1);
}

while(WiFi.status() != WL_CONNECTED){
  Serial.print("Attempting to connect to wifi");
  WiFi.begin(ssid, pass);
  delay(5000);
}
Serial.println("Connected to WiFi");
printWiFiStatus();
}

void loop() {
  // put your main code here, to run repeatedly.

if (millis() - lastUpdateTime >= updateInterval){
  updatesJson(jsonBuffer);
}
}

void updatesJson(char* jsonBuffer){
  /* JSON format for updates paramter in the API
   *  This examples uses the relative timestamp as it uses the "delta_t". You can 
also provide the absolute timestamp using the "created_at" parameter
 *  instead of "delta_t".
 *   "[{\"delta_t\":0,\"field1\":-70},{\"delta_t\":3,\"field1\":-66}]"
 */
// Format the jsonBuffer as noted above
strcat(jsonBuffer,"{\"delta_t\":");
unsigned long deltaT = (millis() - lastUpdateTime)/1000;
size_t lengthT = String(deltaT).length();
char temp[4];
String(deltaT).toCharArray(temp,lengthT+1);
strcat(jsonBuffer,temp);
strcat(jsonBuffer,",");

tcaselect(2);
sensors_event_t orientationData , angVelocityData , linearAccelData, magnetometerData, accelerometerData, gravityData;

bno.getEvent(&orientationData, Adafruit_BNO055::VECTOR_EULER);
bno.getEvent(&angVelocityData, Adafruit_BNO055::VECTOR_GYROSCOPE);
bno.getEvent(&linearAccelData, Adafruit_BNO055::VECTOR_LINEARACCEL);

float rssi = linearAccelData.acceleration.x; 
strcat(jsonBuffer, "\"field1\":");
lengthT = String(rssi).length();
String(rssi).toCharArray(temp,lengthT+1);
strcat(jsonBuffer,temp);
strcat(jsonBuffer,"},");
// If posting interval time has reached 15s, update the ThingSpeak channel with your 
data
if (millis() - lastConnectionTime >=  postingInterval) {
      size_t len = strlen(jsonBuffer);
      jsonBuffer[len-1] = ']';
      httpRequest(jsonBuffer);
}
lastUpdateTime = millis(); // Update the last update time
}

// Updates the ThingSpeakchannel with data
void httpRequest(char* jsonBuffer) {
/* JSON format for data buffer in the API
 *  This examples uses the relative timestamp as it uses the "delta_t". You can also 
provide the absolute timestamp using the "created_at" parameter
 *  instead of "delta_t".
 *   "{\"write_api_key\":\"YOUR-CHANNEL-WRITEAPIKEY\",\"updates\": 
[{\"delta_t\":0,\"field1\":-60},{\"delta_t\":15,\"field1\":200}, 
{\"delta_t\":15,\"field1\":-66}]
 */
// Format the data buffer as noted above
char data[500] = "{\"write_api_key\":\"59IISQVOXV5GGH0D\",\"updates\":"; // Replace 
YOUR-CHANNEL-WRITEAPIKEY with your ThingSpeak channel write API key
strcat(data,jsonBuffer);
strcat(data,"}");
// Close any connection before sending a new request
client.stop();
String data_length = String(strlen(data)+1); //Compute the data buffer length
Serial.println(data);
// POST data to ThingSpeak
if (client.connect(server, 80)) {
  client.println("POST /channels/1683708/bulk_update.json HTTP/1.1"); // Replace 
YOUR-CHANNEL-ID with your ThingSpeak channel ID
  client.println("Host: api.thingspeak.com");
  client.println("User-Agent: mw.doc.bulk-update (Arduino ESP8266)");
  client.println("Connection: close");
  client.println("Content-Type: application/json");
  client.println("Content-Length: "+data_length);
  client.println();
  client.println(data);
}
else {
  Serial.println("Failure: Failed to connect to ThingSpeak");
}
delay(250); //Wait to receive the response
client.parseFloat();
String resp = String(client.parseInt());
Serial.println("Response code:"+resp); // Print the response code. 202 indicates that 
the server has accepted the response
jsonBuffer[0] = '['; //Reinitialize the jsonBuffer for next batch of data
jsonBuffer[1] = '\0';
lastConnectionTime = millis(); //Update the last conenction time
}

void printWiFiStatus() {
  // Print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

// Print your device IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);

// Print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}

However, when I tried to change the update interval to 0.3s (30Hz), the following error massage was given in the Arduino monitor: Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled.

Could someone please help me with this issue. If anything else is needed, I will update immediately.

Many thanks

I want to scale A and B (shown in a picture below) from a known dimension (base of tail light) from an image of an assembled car. The purpose is to get factory dimensions prior to welding my car together because I replaced both quarters, trunk pan, and trunk drop-offs. I replaced the frame rails. I made tubular ones in an effort to make them stronger. The installation of the tail panel will tie everything together. I want to make sure it's right.

Hello!

I`ve got problems with reading last input of a channel field using AT commands, here follows the sketch I'm currently using:

/* String tx_data_r = "GET https://api.thingspeak.com/channels/CHANNEL/fields/4/last.txt?api_key=API_READ_KEY&results=1"; */

String tx_data_r = "GET https://api.thingspeak.com/channels/";
tx_data_r += "CHANNEL";                                                                         
tx_data_r += "/";
tx_data_r += "fields";                                                                    
tx_data_r += "/4/";                                                                            
tx_data_r += "last.txt?api_key=";
tx_data_r += "API_READ_KEY";                                                                 
tx_data_r += "&results=1";                                                                   
tx_data_r += "\r\n";

Serial.print("AT+CIPSEND=");                                                                                                                                              
delay(1000);

Serial.println(tx_data_r.length());                                                                                                                                    
delay(1000);

Serial.println(tx_data_r);
delay(1000);

 This piece of code doesn`t return a valid response, however if I copy/paste
 https://api.thingspeak.com/channels/CHANNEL/fields/4/last.txt?api_key=API_READ_KEY&results=1"
 using a browser I get the right data.

 One more thing, if instead of using a microcontroller I use an USB serial PC interface program  directly connected to 
 my RF module, with                                                                      
 GET https://api.thingspeak.com/channels/CHANNEL/fields/4/last.txt?api_key=API_READ_KEY&results=1
 along with other commands I get the right data too!

 Can anybody tell me what's going on?

 There are no problems with any read related commands.

 If a working sketch is available it will be most welcome!

 Tks in advance for any help! 

Hello guys:

I am having a problem with something I'm doing, I don't know whether it is something related to thingspeak or to my program. I am using Curl library in c to make Get requests to send data to my channel, those data are are measurments of my Analog Discovery 2 device and they are instantaneous, (using the AD2 SDK library which was uploaded recently, and in it they use thingspeak to send the measurments too) . However, the updating to my channel is happenning very slowly (every new sample update happens each 15 seconds). What do you think is causing the problem? is the updating to the channels is usually slow and you can't do thing kind of fast uploading? or is it something that my code fails to communicate with the channel properly. I attached a photo to my program which shows the status of the Curl Get requests (which demonstrates the connectivity problem). Appreciating any help.

Hello, I see a difference in the number of elements returned by: https://api.thingspeak.com/channels/1389063/status.json?offset=0&results=2500&api_key=XXXXXXXXXXXXXX and https://api.thingspeak.com/channels/1389063/feeds.json?offset=0&results=2500&status=true&api_key=XXXXXXXX The first returns only 271 elements, the second 2500 as requested. Why is that?

I am working with an Arduino nodemcu board and a Tmp36 sensor. My channel updates fine if I use my browser with the following: https://api.thingspeak.com/update?api_key=xxxxxxxxx&field1=71, but does not update with the following sketch, although the serial monitor shows the commands are executed:

//Source code to the Temperature Sensor and ThingSPeak Server Blog
String ssid     = "XXX";  // SSID to connect to
String password = "XXX"; // Our virtual wifi has no password (so dont do your banking stuff on this network)
String host     = "api.thingspeak.com"; // Open Weather Map API
const int httpPort   = 443;
String uri     = "/update?api_key=XXXX&field1=";

int setupESP8266(void) {
  // Start our ESP8266 Serial Communication
  Serial.begin(115200);   // Serial connection over USB to computer
  Serial.println("AT");   // Serial connection on Tx / Rx port to ESP8266
  delay(10);        // Wait a little for the ESP to respond
  if (!Serial.find("OK")) return 1;

    // Connect to 123D Circuits Simulator Wifi
    Serial.println("AT+CWJAP=\"" + ssid + "\",\"" + password + "\"");
    delay(10);        // Wait a little for the ESP to respond
    if (!Serial.find("OK")) return 2;

    // Open TCP connection to the host:
    Serial.println("AT+CIPSTART=\"TCP\",\"" + host + "\"," + httpPort);
    delay(50);        // Wait a little for the ESP to respond
    if (!Serial.find("OK")) return 3;

    return 0;
  }

void anydata(void) {

    int temp = map(analogRead(A0),20,358,-40,125);

    // Construct our HTTP call
    String httpPacket = "GET " + uri + String(temp) + " HTTP/1.1\r\nHost: " + host + "\r\n\r\n";
    int length = httpPacket.length();

    // Send our message length
    Serial.print("AT+CIPSEND=");
    Serial.println(length);
    delay(10); // Wait a little for the ESP to respond if (!Serial.find(">")) return -1;

    // Send our http request
    Serial.print(httpPacket);
    delay(1000); // Wait a little for the ESP to respond
    if (!Serial.find("SEND OK\r\n")) return;

}

void setup() {

    setupESP8266();

}

void loop() {

   anydata();

    delay(10000);
  }

hello, i have done my iot project using thingspeak as the monitoring source and its working well and good.But now i need get text message to a mobile when the field value gets reached to given threshold value and i have to get a alert text message.Is there any way to resolve my problem from thigspeak data to alert text message.

Thankyou.

Hi,

I am using Ublox SARA-R410M to send (cellular) data to ThingSpeak cloud. I found in the Ublox manual that AT+UHTTPC (POST data command) can do the job. The link below is the location which my data will be saved on ThingSpeak (field1):

"https://api.thingspeak.com/update?api_key=WRITE_API_KEY&field1="

Note that the "WRITE_API_KEY" is 16 characters (combination of letters and numbers).

AT command: AT+UHTTPC=<profile_id>,5, path,<filename>,<data>,<HTTP_content_type>

Based on the information above, which items should I use for path and filename? And how can I use this command in Arduino code?

I appreciate any help in advance.

Abbas

Hi,

I am using a Sparkfun LTE Shield with a SARA-R410M-02B-01 cellular module, an Arduino UNO, and an AT&T simcard to send data to ThingSpeak. I used "AT+UDNSRN" on Arduino code (below) to find IP address of "api.thingspeak.com". I found two different IPs using this command: "3.224.210.136","3.213.58.187" (also, nslookup command on CMD Windows gives me these IPs). Moreover, I found that some websites report "184.106.153.149" as ThingSpeak's IP. I used the "AT+USOCO" on Arduino code (below) for TCP connection using these three IPs:

Example of the Arduino codes:

lteSerial.println("AT+UDNSRN=0,\"api.thingspeak.com\""); //Find IP address

lteSerial.println("AT+USOCO=0,\"184.106.153.149\",\"80\""); //TCP Connection to ThingSpeak using IP address 

But I got this error (for "AT+USOCO" command):

+CME ERROR: Operation not allowed

Any idea regarding which IP address should I use for "api.thingspeak.com"?

I appreciate any help in advance.

Abbas

I visualise my data with ThingSpeak (data from The Thing Network) and I would like to have something like a button to send a command (downlink). I can send downlink with the thing network but I would like : The thing speak (for interface) -> the thing network (for lora gateway management) -> my device I see talkback and some example with wifi node but it is not my case... Thank you for your reply

I have a fish feeder project running on an Arduino esp 32, it checks various parameter and feeds according to temperature. Unfortunately it has stopped, it no-longer talks to thingspeak and hence cannot upload data. I believe I have a free licence (according to thingspeak) I was only using 1 channel, hence 4 sufficient at this moment. How can I get it working again, ps feeding starts May!. I have googled and understand notice may have been given. Help please- relatively new to Arduino's and first project to us thingspeak. at the moment wireless communication appears more reliable.

If you are interested in live script lecture notes in the following areas, take a look at the short course ( Advanced MATLAB for Scientific Computing ) developed at Stanford. You can also download the required data for the examples from the course GitHub page.

• MATLAB Fundamentals
• Graphics and Data Visualization
• Efficient Code Writing
• System and File Manipulation
• Big Data Handling
• Numerical Linear Algebra
• Numerical Optimization
• Symbolic Toolbox, ODE, and PDE
• Statistical and Machine Learning
• Deep Learning
• Object-Oriented Programming
• Using MATLAB with Other Programming Languages
• Image Processing, Computer Vision, and Image Acquisition
• Signal Processing, Audio, and DSP System

Hola, mi proyecto es con NodeMcu ESP8266, en el puerto serial obtengo datos cada 2 minutos asi esta programado, en la grafica salta datos y algunas veces durante una hora o mas, Qoe podria hacer?

In many universities, introductory programming is taught as a foundation course. Students from different departments are usually brought together to learn to program in these foundation courses. Their home departments may have a programming language preference and that preference may change from department to department. Some universities either strictly teach one language in a single course, some of them teach multiple languages in the same course and give students the flexibility to choose their language for the assignments and projects. How can we make students multilingual when it comes to programming? Is there a way to teach multiple languages in a fair light, side by side without creating a new course or sacrificing one language to teach the other one? Dr. Nathan Kutz from the University of Washington found a creative way to teach MATLAB and Python side by side in his AMATH 301 course. This course is an introductory programming course at the University of Washington and almost all engineering students take it. Do you wonder how Dr. Kutz taught this course? Check out these recordings and course resources! They can be utilized in an in-person or a distance learning setting:

• Main Course Page
• Sample course videos (MATLAB and Python side by side)

I'm monitoring a temp and humidity sensor outside of my house using a ESP32. I have it update every 15 minutes. On my channel I have a chart and numeric readout. The readout shows me that it is updating every 15 minutes but the chart's last update was 2 hours ago. This was working until I went into the properties of the chart and changed the time base from daily to 12 hours. I have tried refreshing the page, signing out and back in as well as reboot the computer, still 2 hours behind. Is there something else I have to do to reestablish the chart?

Thanks John

If you are a student or researcher looking for a project idea, have a look at the MathWorks Excellence in Innovation site. There is at least one IoT-based project for a Smart watering system, and a project with a Digital twin of a pneumatic system. If you ask me, most of the other projects could also be enhanced with an IoT based component shared on ThingSpeak!

#include <Keypad.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
SoftwareSerial ESP01(2, 3);

const byte ROWS = 4; // four rows
const byte COLS = 3; // three columns
char keys[ROWS][COLS] = { // keypad labels
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'*', '0', '#'}
};

byte rowPins[ROWS] = {12, 7, 8, 10};          //connect to keypad pins 12, 7, 8, 10
byte colPins[COLS] = {11, 13, 9};             // connect to keypad pins 11, 13, 9 column pinouts
Keypad customKeypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

#define Password_Length 5
#define DEBUG true
#define IP "184.106.153.149"

// define pin numbers
int buzzer = 5; // buzzer is connected to pin 5
int PIR = 6;    // PIR is connected to pin 6

// intruder alarm password
char Data[Password_Length];
char Master[Password_Length] = "1234";
byte data_count = 0, master_count = 0;
bool Pass_is_good;
char customKey;
int val = 0;

// thingspeak & WiFi
String apiKey = "xxxxxxxxxxxxxxxx"; // thingspeak API key

void setup() {
lcd.init(); 
lcd.backlight();
pinMode(buzzer, OUTPUT);
pinMode(PIR, INPUT);

Serial.begin(9600); 
while (!Serial){
}
Serial.println("Starting...");
ESP01.begin(9600);

// Reset ESP8266, put it into mode 1 i.e. STA only, make it join hotspot / AP, 
// establish single connection
ESP01.println();
sendData("AT+RST\r\n",2000,DEBUG);
sendData("AT+CWMODE=1\r\n",2000,DEBUG);
sendData("AT+CWJAP=\"AiPhone\",\"123889\"\r\n",20000,DEBUG);  
sendData("AT+CIPMUX=0\r\n",4000,DEBUG);

// Make TCP connection
String cmd = "AT+CIPSTART=\"TCP\",\"";
cmd += "184.106.153.149"; // Thingspeak.com's IP address  
cmd += "\",80\r\n";
sendData(cmd,4000,DEBUG);  

// Read PIR sensor value 
  val = digitalRead(PIR);
  // check if there was a state transition

    String val1 = String(val);
    if (val == HIGH)
    {
      Serial.println("Motion detected!");
      delay(10);
      Serial.println(val1);
    }
    else
    {
      Serial.println("Asleep");
      delay(10);
      //String val1 = String(val);
      Serial.println(val1);
    }
      //String val1 = String(val);
      //Serial.println(val1);

//Prepare GET string
String getStr = "GET /update?api_key=";
getStr += apiKey;
getStr += "&field1=";
getStr += val1;
getStr +="\r\n";

// Send data length & GET string
ESP01.print("AT+CIPSEND=");
ESP01.println (getStr.length());
Serial.print("AT+CIPSEND=");
Serial.println(getStr.length());
delay(500);
if(ESP01.find (">"))
{
  Serial.print(">");
  sendData(getStr, 2000, DEBUG);
}

//Close connection, wait a while before repeating
sendData("AT+CIPCLOSE", 16000, DEBUG); // 15 seconds delay between updates
}

if true
  % code
endvoid loop() {

if (digitalRead(PIR) == HIGH)
{
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password: ");

    customKey = customKeypad.getKey();
    if (customKey)
    {
      Data[data_count] = customKey;
      lcd.setCursor(data_count, 1);
      lcd.print(Data[data_count]);
      data_count++;
    }

    if (data_count == Password_Length - 1)
    {
      lcd.clear();

      if (!strcmp(Data, Master))
      {
        lcd.print("OK");
        digitalWrite(buzzer, HIGH);
        delay(200);
        digitalWrite(buzzer, LOW);
        delay(200);
        digitalWrite(buzzer, HIGH);
        delay(200);
        digitalWrite(buzzer, LOW);
      }
      else
      {
        lcd.print("Wrong Password");
        digitalWrite(buzzer, HIGH);
        delay(1000);
        digitalWrite(buzzer, LOW);
      }

      lcd.clear();
      clearData();
    }
  }
  else
    {
      lcd.noBacklight();      // turn backlight off
      lcd.clear();            // clear display
      delay(250);
    }
}

String sendData(String command, const int timeout, boolean debug)
{
  String response = "";
  ESP01.print(command);
  long int time = millis();

    while( (time+timeout) > millis())
    {
      while(ESP01.available())
      {
        // "Construct" response from ESP01 as follows 
         // - this is to be displayed on Serial Monitor. 
        char c = ESP01.read(); // read the next character.
        response+=c;
      }  
    }

    if(debug)
    {
      Serial.print(response);
    }

    return (response);
}

void clearData() {
  while (data_count != 0)
{
  Data[data_count--] = 0;
  }
  return;
}