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I wanted to use MQTT to publish data to my ThingSpeak client. However, on one of the forums it said, "The MQTT broker does not presently parse JSON".
Hello. I am working on a project to monitor agricultural variables. The module that I designed transmits the data by GSM, with the SIM800 module every 30 minutes takes a sample. My problem is the following, I need to transmit the stored data every 2 hours every 30 minutes, but I don't know how to do that. In the line of code "GET / update? Api_key = EXNLVJJTBY17SM8V & field1 = ........", you can add the time of each sample. This would save energy by sending 4 data every 2 hours
if true
altSerial.println("AT+CIPSHUT");delay(4000);
altSerial.println("AT+CIPSTATUS");
delay(5000);
altSerial.println("AT+CIPMUX=0");delay(5000);
altSerial.println("AT+CSTT=igprs.claro.com.ar");delay(2000); altSerial.println("AT+CIICR");delay(5000); altSerial.println("AT+CIFSR");delay(5000); //altSerial.println("AT+CIPSPRT=0");delay(4000); altSerial.println("AT+CIPSTART=\"TCP\",\"184.106.153.149\",\"80\"");delay(3000);//String mensaje
String S_Bateria =String(Bateria,2);
String Humedad_1 = String(S_Humedad_1,2);
String Humedad_2 = String(S_Humedad_2,2);
String fila = String("&field2=");
String fila1 = String("&field3=");
String stringUno= String("GET /update?api_key=EXNLVJJTBY17SM8U&field1=");
String URL =String(stringUno + Humedad_1 + fila + Humedad_2 + fila1 + S_Bateria);
int Largo=URL.length();
Largo= Largo+3;
String Memoria= String (String("AT+CIPSEND=")+String(Largo));altSerial.println(Memoria);delay(2000);
altSerial.println(URL);altSerial.println(""); //altSerial.println((char)26);puerto();delay(4000);
delay(15000);
altSerial.println("AT+CIPSHUT");delay(4000);
end
Hi i want to ask is there any way that we can add more field in our channel? because by default the field is only eight and i need to use more field
This is a great presentation from 2 professors introducing how they use MATLAB in their physics courses. MATLAB Grader and Live Scripts are discussed in detail.
Here is the abstract:
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Guest Presenters: Michele McColgan, Siena College and Duncan Carlsmith, UW Madison
The meeting will start with short presentations, and then we'll have time for questions and discussion in a colloquial setting. The presenters use MATLAB in their courses, and this meeting will provide a good opportunity to see the functionality that MATLAB affords. However, the presenters' approach to integrating computation is relevant generally; thus, this meeting should be of great interest, even if you are not a MATLAB user.
-----
Webinar from PICUP .
Hi, I am sending data from my device to the thingspeak server using HTTP and I'm trying to attach a timestamp with my uploads. I am using the created_at field in the request to set the time zone. A sample request looks like this
I live in India and my timezone offset is 5 hours 30 min. When I specify it like as shown above, I can see in the private view of my channel that it is adding 5 hours 30 min to the given time zone. So this time stamp becomes 21:04. How do I fix this? Am I making some mistake in my time zone offset in created_at? Or is there some time zone setting that is not set properly in my channel?
Thanks, Ashwin N
I followed the instructions here: Bulk-Update Using an Arduino or an ESP8266
And came up the following code for GSM module:
const char apn[] = "www";
const char gprsUser[] = "";
const char gprsPass[] = "";const char simPIN[] = "";
const char server[] = "api.thinkspeak.com";
const int port = 80;char jsonBuffer[500] = "["; // Initialize the jsonBuffer to hold data
// TTGO T-Call pins
#define MODEM_RST 5
#define MODEM_PWKEY 4
#define MODEM_POWER_ON 23
#define MODEM_TX 27
#define MODEM_RX 26 #define SerialMon Serial
#define SerialAT Serial1
#define TIMEOUT 5000
// Configure TinyGSM library
#define TINY_GSM_MODEM_SIM800 // Modem is SIM800
#define TINY_GSM_RX_BUFFER 1024 // Set RX buffer to 1Kb #include <TinyGsmClient.h>
#ifdef DUMP_AT_COMMANDS
#include <StreamDebugger.h>
StreamDebugger debugger(SerialAT, SerialMon);
TinyGsm modem(debugger);
#else
TinyGsm modem(SerialAT);
#endifTinyGsmClient client(modem);
#define IP5306_ADDR 0x75
#define IP5306_REG_SYS_CTL0 0x00 /* Collect data once every 15 seconds and post data to ThingSpeak channel once every 2 minutes */
unsigned long lastConnectionTime = 0; // Track the last connection time
unsigned long lastUpdateTime = 0; // Track the last update time
const unsigned long postingInterval = 60L * 1000L; // Post data every 2 minutes
const unsigned long updateInterval = 15L * 1000L; // Update once every 15 seconds void setup() {
SerialMon.begin(115200); // Set modem reset, enable, power pins
pinMode(MODEM_PWKEY, OUTPUT);
pinMode(MODEM_RST, OUTPUT);
pinMode(MODEM_POWER_ON, OUTPUT);
digitalWrite(MODEM_PWKEY, LOW);
digitalWrite(MODEM_RST, HIGH);
digitalWrite(MODEM_POWER_ON, HIGH); // Set GSM module baud rate and UART pins
SerialAT.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX);
delay(3000); SerialMon.println("Initializing modem...");
modem.init();// Configure the wake up source as timer wake up
SerialMon.print("Connecting to APN: ");
SerialMon.print(apn);
if (!modem.gprsConnect(apn, gprsUser, gprsPass)) {
SerialMon.println(" fail");
}
else {
SerialMon.println(" OK"); SerialMon.print("Connecting to ");
SerialMon.print(server);
if (!client.connect(server, port)) { SerialMon.println(" Fail");
}
else {
SerialMon.println(" OK");
}
}}
void loop() {
// If update time has reached 1 second, then update the jsonBuffer
if (millis() - lastUpdateTime >= updateInterval) {
updatesJson(jsonBuffer);
}}
// Updates the josnBuffer with data
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,",");
int h = hallRead();
strcat(jsonBuffer, "\"field1\":");
lengthT = String(h).length();
String(h).toCharArray(temp,lengthT+1);
strcat(jsonBuffer,temp);
strcat(jsonBuffer,"},");
// If posting interval time has reached 2 minutes, 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\":\"XXXXXXXXXXXXXXXX\",\"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/1300373/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 (ESP8266)");
client.println("Connection: close");
client.println("Content-Type: application/json");
client.println("Content-Length: "+data_length);
client.println();
client.println(data);
String answer=getResponse();
Serial.println( answer );
}
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
} String getResponse(){
String response;
long startTime = millis(); delay( 200 );
while ( client.available() < 1 && (( millis() - startTime ) < TIMEOUT ) ){
delay( 5 );
} if( client.available() > 0 ){ // Get response from server.
char charIn;
do {
charIn = client.read(); // Read a char from the buffer.
response += charIn; // Append the char to the string response.
} while ( client.available() > 0 );
}
client.stop(); return response;
}The Response code I was getting initially was "0" Upon consulting the forum I added a new function to get response and here is the message it produced:
HTTP/1.1 405 Not Allowed Server: nginx Date: Wed, 17 Feb 2021 06:27:54 GMT Content-Type: text/html Content-Length: 8911 Connection: close ETag: "5e5304fb-22cf" X-DIS-Request-ID: 82c8c8535e18295aaeec025d18d14375 Set-Cookie: dis-remote-addr=1.39.31.10 Set-Cookie: dis-timestamp=2021-02-16T22:27:54-08:00 Set-Cookie: dis-request-id=82c8c8535e18295aaeec025d18d14375 X-Frame-Options: sameorigin
Please help me understand this error and rectify the code. P.S. I was able to run the code using WiFi module of the ESP32, so is this something to do with 256 limit? If so, how do I rectify it?
After I give the commands I get a response like this
AT+CIPSTART="TCP","api.thingspeak.com","80" OK
CONNECT OK AT+CIPSEND > GET https://api.thingspeak.com/update?api_key=Q03CA55P7NVGA8S8&field1=23 SEND OK
CLOSED
But the field charts are not updated in the website. And the data widget shows "no data available to show". And the number of entries remains 0. kindly help me out why I didn't get the values.
I have an Esp8266 weather station and I want the graphs in thingspeak to display customary units instead of metric. How do I do it?
Prof. Duarte Antunes from Eindhoven University of Technology explains how he's been using MATLAB live scripts for teaching an online "Optimal Control and Dynamic Programming" course.
Hello,
I would like to share a channel with some users, but when I do it, they can see the channel in "Channels share with me" but when they open the channel the can not see the data inside. There is a message saying: You don't have permission to view that channel! Do you know why is that? Thank you.
Hi there, my PI submitted some (3) wrong values to my channel. I didn't find am opportunity to remove them. Can anoyone help or give me a hint? Those 3 wrong values are killing my statistic and let the chart look very wrog due to those peaks Thanx to you
ok I want to extract all those rows in a table where one column has strings in which it shall contain the word "change" specifically after the word "terms" . text is : May not be redeemed for cash or combined with any other offer or coupon. Not valid on clearance (merchandise ending in .98). May not be applied to taxes, previous purchases, or the purchase of gift cards. Non-transferable. Terms are subject to change at any time. Product styles are subject to availability. See store associate for details.
WiDS Datathon 2021 is going on right now. The focus of the Datathon this year is "on creating models to classify whether patients have been diagnosed with a certain type of diabetes." You can register and participate until March 1.
Also, take a look at this blog post on the MATLAB benchmark code for this datathon.
MATLAB Benchmark Code for WiDS Datathon 2021
There are also various online challenges by MathWorks that students may be interested. Here are the winners from last year's Simulink Student Challenge. There was also a MATLAB Online Live Editor Challenge a couple of years ago.
Hello, I am interested in creating an IoT academic project, but I have encountered two difficulties: 1- It is necessary that in the ThingSpeak interface you can see a live camera. I have not found documentation or any information on how to do it. Yes, I know that you can import data from other websites (copy XPath), but I have not achieved it with traffic cameras from local websites. 2- I also need to act remotely on actuators, is this possible in ThingSpeak?
I would appreciate an honest answer, since in case of not being able to implement these solutions, I will have to find another platform or method to carry out this. Regards!
Hi,
I would like to export data from my channel. My channel receives data every 15 minutes but I would like to export the data similar to what I can see when I change the chart/field's timescale to 60 minutes.
Thanks!
Hello , I wonder how to determine continous or discrete time modelling.For example if I want to run my model in MCU in this case discrete model is suitable?I am a bit confused
Hi everyone,
I have been using Thingspeak for quite some time now for monitoring data for my wife‘s greenhouse. She accesses those data via the public view of the channel. So far, so good.
Now someone has used the „feature“ to add a comment to that view. Nothing serious, but my wife isn‘t happy. Therefore she asked me to remove the comment, and to set things up in such a way that comments can no longer be added.
Thus my two questions: 1. How can I delete the comment? 2. How can I disable comments made by not signed on users?
The channel in question is https://thingspeak.com/channels/971602
With best regards
Volker Bandke
I'm presently working on an Air Quality monitor to be able to check the status of my environment and remote environments on ThingSpeak. I was planning on using the BME680 sensor. Does anyone have any experience with this or other air quality sensors? I'm looking probably for CO2 and the like (Volatile Organics), not so much particle sensors, though a combination may be best.
Hi,
I set at the Chart Options Results on 40320, what should be one week. But the graph shows only 36 hours (and some minutes). I also try to set it results on 7 day, but still I get only 36 hours.
Why it is not showing 7 days graph?
Frank
https://thingspeak.com/channels/1222127
Here's an example of virtualizing a lab course.
