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Definitely not
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15%
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11%
Yes, somewhat
18%
Yes, definitely
20%
Not sure
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4598 votes
Hello, I am trying to display my Charts in a React Native App but I can't figure out what is the URL that I should use to display it. Any ideas?
Salve, ho appena realizzato la stazione meteo con l'esp8266 ma non riesco a capire come impostare l'ora di roma (it) sul display. Qualcuno può aiutarmi? Grazie.
I want to fit a circle just like the black line drawn in the figure and trying to find its radius. below is the code i am writing but not getting anything significant. kindly help me how to approch this kind of problems
%%---------------------------- matlab code -----------------------------------%%
clear all
clc
% read the image
img = imread('gra.png');
% convert the image to grayscale
img_gray = rgb2gray(img);
% perform edge detection using the Canny algorithm
edge_img = edge(img_gray, 'sobel');
% perform hough transform to detect circles
[centers, radii] = imfindcircles(edge_img, [10 50000],'ObjectPolarity','bright','Sensitivity', 0.95);
% find the largest circle
[max_r, max_i] = max(radii);
max_center = centers(max_i, :);
% plot the results
figure;
imshow(img);
hold on;
viscircles(max_center, max_r, 'EdgeColor', 'b');
Need some guidance on how to model the mutual inductance model from Simscape. The secondary side does not receive the voltage.
Hi,
I'm trying to communicate with my channel ohowever it looks like I'm missing something as my data doesn't appear in the feeds. Below is my code:
#define SW_VERSION " ThinkSpeak.com" // SW version will appears at innitial LCD Display
#define TINY_GSM_MODEM_SIM900
#include <TinyGsmClient.h>
#define SerialAT Serial
TinyGsm modem(SerialAT);
TinyGsmClient client(modem);
/* ESP12-E & Thinkspeak*/
const char apn[] = "xxxxx";
const char user[] = "";
const char pass[] = "";
const char server[] = "api.thingspeak.com";
const int port = 80;
const char* TS_SERVER = "api.thingspeak.com";
String TS_API_KEY ="xxxxx";
int sent = 0;
/* TIMER */
#include <SimpleTimer.h>
SimpleTimer timer;
/* OLED */
#include <ACROBOTIC_SSD1306.h> // library for OLED: SCL ==> D1; SDA ==> D2
#include <SPI.h>
#include <Wire.h>
/* DHT22*/
#include "DHT.h"
#define DHTPIN D3
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);
float hum = 0;
float temp = 0;
/* Soil Moister */
#define soilMoisterPin A0
#define soilMoisterVcc D4 //not used. LM393 VCC connect to 3.3V
int soilMoister = 0;
/* DS18B20 Temperature Sensor */
#include <OneWire.h>
#include <DallasTemperature.h>
#define ONE_WIRE_BUS 14 // DS18B20 on NodeMCU pin D5 corresponds to GPIO 014 on Arduino
float soilTemp;
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature DS18B20(&oneWire);
void setup()
{
Serial.begin(115200);
delay(10);
Serial.println(".... Starting Setup");
SerialAT.begin(115200);
delay(3000);
// Restart takes quite some time
// To skip it, call init() instead of restart()
Serial.println("Initializing modem...");
modem.init();
pinMode(soilMoisterVcc, OUTPUT);
Serial.begin(115200);
delay(10);
oledStart();
dht.begin();
DS18B20.begin();
timer.setInterval(2000L, getDhtData);
timer.setInterval(7000L, getSoilMoisterData);
timer.setInterval(9000L, getSoilTempData);
timer.setInterval(19000L, sendDataTS);
digitalWrite (soilMoisterVcc, LOW);
}
void loop()
{
displayData();
timer.run(); // Initiates SimpleTimer
}
/***************************************************
* Start OLED
**************************************************/
void oledStart(void)
{
Wire.begin();
oled.init(); // Initialze SSD1306 OLED display
clearOledDisplay();
oled.clearDisplay(); // Clear screen
oled.setTextXY(0,0);
oled.putString(" ");
}
/***************************************************
* Get DHT data
**************************************************/
void getDhtData(void)
{
float tempIni = temp;
float humIni = hum;
temp = dht.readTemperature();
hum = dht.readHumidity();
if (isnan(hum) || isnan(temp)) // Check if any reads failed and exit early (to try again).
{
Serial.println("Failed to read from DHT sensor!");
temp = tempIni;
hum = humIni;
return;
}
}
/***************************************************
* Get Soil Moister Sensor data
**************************************************/
void getSoilMoisterData(void)
{
soilMoister = 0;
digitalWrite (soilMoisterVcc, HIGH);
delay (500);
int N = 3;
for(int i = 0; i < N; i++) // read sensor "N" times and get the average
{
soilMoister += analogRead(soilMoisterPin);
delay(150);
}
digitalWrite (soilMoisterVcc, LOW);
soilMoister = soilMoister/N;
Serial.println(soilMoister);
soilMoister = map(soilMoister, 689, 274, 0, 100);
}
/***************************************************
* Get SoilTemp sensor data
**************************************************/
void getSoilTempData()
{
DS18B20.requestTemperatures();
soilTemp = DS18B20.getTempCByIndex(0);
int newData = ((soilTemp + 0.05) * 10); //fix soilTemp value to 1 decimal place.
soilTemp = (newData / 10.0);
}
/***************************************************
* Display data at Serial Monitora & OLED Display
**************************************************/
void displayData(void)
{
Serial.print(" Temperature: ");
Serial.print(temp);
Serial.print("oC Humidity: ");
Serial.print(hum);
Serial.println("%");
Serial.print("SoilTemp: ");
Serial.print(soilTemp);
Serial.print("oC");
oled.setTextXY(1,0); // Set cursor position, start of line 2
oled.putString("TEMP: " + String(temp) + " oC");
oled.setTextXY(3,0); // Set cursor position, start of line 2
oled.putString("HUM : " + String(hum) + " %");
oled.setTextXY(5,0); // Set cursor position, start of line 2
oled.putString("Tsoil:" + String(soilTemp) + " oC");
oled.setTextXY(7,0); // Set cursor position, start of line 2
oled.putString("Hsoil: " + String(soilMoister) + " %");
}
/***************************************************
* Clear OLED Display
**************************************************/
void clearOledDisplay()
{
oled.setFont(font8x8);
oled.setTextXY(0,0); oled.putString(" ");
oled.setTextXY(1,0); oled.putString(" ");
oled.setTextXY(2,0); oled.putString(" ");
oled.setTextXY(3,0); oled.putString(" ");
oled.setTextXY(4,0); oled.putString(" ");
oled.setTextXY(5,0); oled.putString(" ");
oled.setTextXY(6,0); oled.putString(" ");
oled.setTextXY(7,0); oled.putString(" ");
oled.setTextXY(0,0); oled.putString(" ");
}
/***************************************************
* Sending Data to Thinkspeak Channel
**************************************************/
void sendDataTS(void)
{
if (client.connect(TS_SERVER, 80))
{
String postStr = TS_API_KEY;
postStr += "&field1=";
postStr += String(temp);
postStr += "&field2=";
postStr += String(hum);
postStr += "&field3=";
postStr += String(soilMoister);
postStr += "&field4=";
postStr += String(soilTemp);
postStr += "\r\n\r\n";
client.print("POST /update HTTP/1.1\n");
client.print("Host: api.thingspeak.com\n");
client.print("Connection: close\n");
client.print("X-THINGSPEAKAPIKEY: " + TS_API_KEY + "\n");
client.print("Content-Type: application/x-www-form-urlencoded\n");
client.print("Content-Length: ");
client.print(postStr.length());
client.print("\n\n");
client.print(postStr);
delay(1000);
}
sent++;
client.stop();
}
First I get this on my serial monitor:
After some time:
And after some more time:
With my limited knowledge on the subject I can't figure it out.
Any help would be appreciated.
Thanks.
Not able to display password by copying to clipboard or by clicking the unhide icon - have tried multiple computers.
Anyone else had this problem with mqtt?
I am sending my sensor readings to thingspeak channel using raspberrry pi board but i dont know how can we send some instruction back to the raspberry pi board to control an LED or Motor or some other things. Can anyone provide some information about this?
Congratulations, @Daniel Vieira for winning the Editor's Pick badge awarded for MATLAB Answers, in recognition of your awesome solution in Why are the results of forward and predict very different in deep learning?
Thank you for providing considered advice about reinforcement learning.
This is a new badge we just introduced to recognize awesome answers people contribute and yours was picked for discovering a creative way to solve the problem, and made the solution clear, and reproducible. Thank you so much for setting a high standard for MATLAB Answers and for your ongoing contribution to the community.
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can't connect using the following setting in MQTT explorer
should i modify thiem or it's a must to use MQTTX
please advice
I note that there is a limit of 12 TimeControls per user. Is that only for free and Home users, or for Commercial users too? If the latter, that will put a dent in my plans. I basically want to calculate daily averages and send customers an SMS once per day with their summary data.
I have this message "You have a React with similar Test Frequency, Action, and Option settings. Delete that React to save this one."
But that's not true. It's another channel, another field that must trigger another matlab analysis...........
Any idea on how to unblock this issue?
Thank you
hi, my tracker using A9G always giving incorrect coordinates 999.00.please help
My learning is progressing well. I borrow heavily on examples given on this site. I need to know the correct commands for coding in Matlab analysis. For a simple example, what is the correct code symbol for multiplication? Yes, I know it is (a)*(b). But, is there a glossary of all such? For another example, I tried to generate a random number in Matlab analysis by writing: mu = 1; sigma = 5; rannum = Random (‘Normal’, mu, sigma)
But when I run this code I get the following error message: .....
“random” requires access to one of the following...
Sim Biology or
Statistics & Machine Learning Toolbox...
So, in summary, does my subscription allow such access and/or how do I learn the syntax Matlab requires for code operations?
Thanks.
For Q&A
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For programming tasks
27%
For writing
9%
For fun
26%
Other use-case not mentioned here
3%
What's ChatGPT?
17%
4555 votes
In the Matlab analysis option on my Thingspeak channel I chose to experiment with the example in the title regarding humidity average. It works fine but only works once. How can I keep it updating every 5 minutes or so?
I am very happy with ThingSpeak. I have a prototype Pico W project that it working well.
I tried 6 other IOT platforms and ThingSpeak was the BEST!
I wrote about my experience here:
Hi all,
I am wondering whats the total cost to use MATLAB for algo trading. The transparent part is of coz the price of matlab and the toolboxes. But I was shocked to find out the APIs to connect to Interactive Brokers are not free (costly in fact!). Is there free API to connect to IB? What other hidden costs are there? I saw the X Trader in the Automated Trading with MATLAB video. Is this XTrader software part of MATLAB toolbox? Do we need to pay additional to Trading Technologies (to use X_Trader). Also what data feed is the most cost effecient? Is there any additional hidden cost that I am not aware of?
Thanks!
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Hi
I used to have the following daily max, min and mean code working. But, this week it seems to work for max and mins but not means. Any idea what's going on?
writeAPIKey = 'xxxxxx';
% Define date range of 1 day
end1 = datetime('now')
start=datetime('today')
% Read Weight data from Field1 for last 24 hrs
[Weight, time] = thingSpeakRead(xxxxxx,'DateRange', [start,end1], 'Fields', [1]);
Wtmax = max(Weight); % Get 24hr Max
Wtmin = min(Weight); % Get 24hr Min
Wtav = mean(Weight); % Get 24hr Av
% display results
display(Wtmax, 'Wt_max'), display(Wtmin, 'Wt_min'), display(Wtav, 'Wtav');
Output:
end1 =
datetime
30-Jan-2023 14:00:35
start =
datetime
30-Jan-2023
Wt_max =
-0.0685
Wt_min =
-0.5190
Wtav =
NaN
