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I have created a mqtt device in thingspeak, allocated a channel for pub and sub. I noted down the credentials for connection when the device was created. I tried to connect using the host mqtt3.thingspeak.com port 1883 and the supplied credentials(user name and password). I tried with node red (mqtt node) and also mqtt lense but still cannot connect. Would appreciate advice some advise. Thanks
Joseph
Joseph
Last activity on 15 May 2023

Up until yesterday (May 6, 2023), time controls were working fine in regards to running my Analysis code recurring at specified intervals. Now they will no run more than once? I’ve tried creating new time controls but no luck. I have to manually run the code to get updated results.

How can I display a string value using thingspeak visualization ? for example name, gender, bloodgroup,etc.

dave
dave
Last activity on 4 May 2023

Hello - I have a new account and when I click My Channels, I don't get a drop down menu with choices like My Channels, My Image Channels, ect. I only get Public Channels when I click the Channels tab. I can't select My Channels. Could someone please help me?
Thank you
Ali
Ali
Last activity on 4 May 2023

We need to do IoT work for our university project. I want to open a channel without any profit motive so that I can see the statistics. New Channel option does not appear.
After signing in pop up showing succesfully signed in ,but its getting signed out automatically
plz help me and comment if you are facing same problem
I try this code in MATLAB:
This code working fine:
readChannelID = [1788078];
fieldID1 = [1];
readAPIKey = '';
[data, time] = thingSpeakRead(readChannelID, 'Field', fieldID1, 'NumPoints', 30, 'ReadKey', readAPIKey);
plot(time, data);
This code have error : Unrecognized table variable name 'x1'.
readChannelID = [1788078];
fieldID1 = [2];
readAPIKey = '';
[data, time] = thingSpeakRead(readChannelID, 'Field', fieldID1, 'NumPoints', 30, 'ReadKey', readAPIKey);
plot(time, data);
What i do wrong? Thanks.
Hello,
I want to make a weather forecast for the next 3 days using the data I received from my sensors on the thingsspeak server I gave the link above, how can I do this?
I need to do it with mathlab code in Thingsspeak system but I am very new to Mathlab.
Thanks for your help.
Bill
Edward
Edward
Last activity on 16 Apr 2024

I have used this code but nothing is showing in my channel any suggesrtions please- the internet connects and the temperature output shows but nothing in my channel
#include <OneWire.h>
#include <DallasTemperature.h>
#include <WiFiNINA.h>
// Data wire is plugged into port 2 on the Arduino
#define ONE_WIRE_BUS A0
// WiFi credentials
const char* ssid = "xxxxxxx";
const char* password = "xxxxxxxxx";
// ThingSpeak settings
const char* server = "api.thingspeak.com";
const char* apiKey = "xxxxxxxxxxxxxxxx";
const int httpPort = 80;
// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);
// create an instance of the WiFi class
WiFiClient client;
void setup(void)
{
// start serial port
Serial.begin(9600);
Serial.println("Dallas Temperature IC Control Library Demo");
// Connect to WiFi network
Serial.print("Connecting to WiFi...");
while (WiFi.status() != WL_CONNECTED) {
WiFi.begin(ssid, password);
delay(1000);
Serial.print(".");
}
Serial.println();
Serial.println("WiFi connected");
// Start up the library
sensors.begin();
}
void loop(void)
{
// call sensors.requestTemperatures() to issue a global temperature
// request to all devices on the bus
Serial.print("Requesting temperatures...");
sensors.requestTemperatures(); // Send the command to get temperatures
Serial.println("DONE");
Serial.println(",");
Serial.print("Temperature for the device 1 (index 0) is: ");
float tempC = sensors.getTempCByIndex(0);
Serial.println(tempC);
delay(1000); // update sensor reading each one second
// Send data to ThingSpeak
if (client.connect(server, httpPort)) {
String data = "&Field 1=" + String(tempC);
Serial.println("Connecting to ThingSpeak...");
client.println("POST /update HTTP/1.1");
client.println("Host: api.thingspeak.com");
client.println("Connection: close");
client.println("Content-Type: application/x-www-form-urlencoded");
client.println("Content-Length: " + String(data.length()));
client.println();
client.println(data);
client.println();
Serial.println("Data sent to ThingSpeak");
} else {
Serial.println("Error connecting to ThingSpeak");
}
client.stop();
delay(15000); // Send data to ThingSpeak every 15 seconds
}
I'm running the same code as a week ago but now it reports the error: MATLAB code has timed out.
Currently, I am on a test account with Thingspeak but it would be no problem to upgrade to a subscription plan if it provides the required features.
I would like to edit the time scale (currently only around 10h) and export time (currently only around 24h) for the graphs and the export function in the public channel.
How is this possible? It would be nice to have the option to plot 12h, 1d, 1w, 1m etc. in the graphs and also have the respective export function.
I have purchased an 8in1 weather station from Seed (see Link here), added it to TheThingsStack v3 and changed the payload formatter such that I receive following payload:
{
"barometric_pressure": 96920,
"battery": 0,
"humidity": 92,
"light_intensity": 11848,
"rain_gauge": 0,
"temperature": 6.8,
"uv_index": 0.6,
"wind_direction": 60,
"wind_speed": 0
}
I have followed the ThingSpeak manual here, which seems pretty straight forward to me: just add channel ID and Write Api Key.
However, on TheThingsStack, I see following error:
"data": {
"@type": "type.googleapis.com/ttn.lorawan.v3.ErrorDetails",
"namespace": "pkg/applicationserver/io/web",
"name": "request",
"message_format": "request",
"correlation_id": "XXXXprivate",
"code": 14,
"details": [
{
"@type": "type.googleapis.com/google.protobuf.Struct",
"value": {
"body": "error_too_many_requests",
"status_code": 429,
"url": "https://api.thingspeak.com/things_network/v3/update/",
"webhook_id": "loraweatherstation"
}
}
]
},
[...]
"visibility": {
"rights": [
"RIGHT_APPLICATION_TRAFFIC_READ"
]
TheThingSpeak reports entries without the actual data. I think the entries are generated with all get requests.
Hello,
can someone help me with HEV model? I have no experience with simulink modeling, maybe someone have any simple HEV models or any tutorials how to start everything? :)
Thank you.
Dear team,
i have issue regarding not shown values thingspeak
I am using simulink to generate a simple ADC sampling code. I configured ADC module in software mode, which updates the sampled value according to the sample time configured in the module. I set the sample time to 1e-4, 1e-5, 1e-6 respectively. But it seems that the sampling speed did not reach the value I set. I suspect it has something to do with the read and write operations, but I am not sure if that's the reason.
I also tried to do it using PWM event to trigger the start of conversion of ADC. Same problem happened. Because I connect a potentiometer and turn its knob slowly, the Graph on CCS is correct while when I turn it very quickly, the graph is not able to keep up with my movements. So the sampling rate is surely not enough. I wonder what I should do to successfully configure this model, thanks in advance!
Bonjour,
pour un projet d'école j'ai besoin de faire analyser des données saisies directement dans Appinventor et non pas à partir de capteurs. J'ai cherché un peu partout sur le web mais je n'ai pas trouvé la solution. Quelqu'un peut il m'aider ?
Hi there,
Truncation error happens when an infinite series is ignored except for a small subset of its values. For instance, the exponential function e^x could be written as the infinite series total of 1 + x + x^2/2 + x^3/6 +... + x^n/n! +....
Any finite number of n will result in an approximation of the value of e^x that is inaccurate, but by increasing n, the error can be reduced to the desired level but this increase computation time.
How can I speed up the calculation by determining the dynamic level where error can be reduced to the barest minimum?
The error is different for each input; if the input number is small, the error condition can be reached quickly, say 1e-6; if the input number is large, we need more terms in the polynomial equation, i.e. more iteration; how can I make the threshold dynamic so that I don't have a fixed error tolerance number?
What I want to know is how to make the threshold dynamic so that I can decrease the polynomial's order and lower the number of terms, which will speed up execution time.
Any assistance would be greatly appreciated.
format long e
[exp(log(2)/2), 1+log(2)/2 + (log(2)/2)^2/factorial(2) + (log(2)/2)^3/factorial(3) + (log(2)/2)^4/factorial(4),(exp(log(2)/2) - 1+log(2)/2 + (log(2)/2)^2/factorial(2) + (log(2)/2)^3/factorial(3) + (log(2)/2)^4/factorial(4))]
[exp(-log(2)/2), 1+(-log(2)/2) + (-log(2)/2)^2/factorial(2) + (-log(2)/2)^3/factorial(3) + (-log(2)/2)^4/factorial(4),(exp(log(2)/2) - 1+log(2)/2 + (log(2)/2)^2/factorial(2) + (log(2)/2)^3/factorial(3) + (log(2)/2)^4/factorial(4))]
Hello,
I have an Open Loop Transfer Function:
Gc(s)Gp(s) = aKp(1+Tis) / Tis(s+1+p)
It was decided for this system a=5, Ti=0.1 and p=0.5
What would the poles and zeroes be for this?
Ive done the other examples but this one looks very different to the other questions and it has me stuck.
Any help is appreciated and sorry if this is the wrong place to post such questions.
"The model is configured to create a SIL block, which is not supported for the selected hardware board. To resolve this, search for 'Create block' in the Configuration Parameters dialog box and set it to 'None' or 'PIL'.
Peter
Peter
Last activity on 6 Apr 2023

I am using the standard code written by Daniel. The temperature is giving -11.8 and the humidity 150. This is not for all data points. Any help would be appreciated