結果:
There are two kinds of text data type (=string data type) in MATLAB:
Text1='aText'; % first one
Text2="aText"; % first one
The second one did not exist in "old" MATLAB versions but the first one only.
My questions are: 1) What was motivation of MathWorks programmers to introduce the Text Data Type of the second format?
Yes, I know the difference: length(Text1)=5 whilst length(Text2)=1; Text1(2)='T' but Text2(2) does not exist. The array Text3=['one' ; 'fifth'] does not exist too.
2) However, any explanations and recommendations how to apply the second sort in contrast to the first one?
3) Is there any way how to convert one sort to another one?
Thanks for explanation in advance!
Hi, I want to collect the simulation data by using NASA HL-20 model, then the data will transmit to ThingSpeak. However, I don't have the block for ThingSpeak Channel at the Simulink Library Browser. Is it because the block has its own version of simulink (meaning I have to update my version) or is there any else that I don't know? Besides, can you suggest which methods are suitable for me to successfully transfer the simulation data to ThingSpeak?
We have to create a few 10s of channels all with the same public view and settings. Is there any way of automating this ?
Doing it manually is time consuming and results in omissions and small mistakes.
Hi there, I am trying to reach out to anyone who has successfully completed the project of building a weather station using an Arduino MKRFOX1200 board, a dht11 sensor across the Sigfox and Thingspeak networks. I’ve been attempting to build the weather station over the SigFox and things.io network for over a year now but I was unsuccessful. I then found this tutorial on how to build this using Thingspeak: https://create.arduino.cc/projecthub/masteruan/arduino-mkr-fox-1200-sigfox-meteo-station-423609 . I have now been attempting to build it using this network but am still unsuccessful.
My SigFox and arduino is working. I made the arduino code convert temperature to Celsius (rather than Kelvin which is what the tutorial does). However, I am unable to access the location of the device on Thingspeak (my SigFox atlas is activated) and I am getting humidity values of approximately -30k. Please may someone assist me or give me a detailed approach on how to fix these issues. My goal is to have my thingspeak like this: https://thingspeak.com/channels/227248. I have followed the tutorial and projecthub but I cannot figure out why I am obtaining a confusing humidity reading. Please please may someone help.
Thank you so much for your time.
hello, how i can show module image in to public view.
in widget public dont show the option.
exist any code for MATLAB?
Error: The server timed out while running and assessing your solution in MATLAB CODY. How do I resolve this? My code is correct. I have run it on PC. But, when i submit in CODY the server throws an error.
hello, i buy a license for upload images to channel and ESP32CAM, after compile and upload the example code, then reset the esp32.
the serial monitor only show
Brownout detector was triggered
ets Jun 8 2016 00:22:57
rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0018,len:4
load:0x3fff001c,len:1216
ho 0 tail 12 room 4
load:0x40078000,len:10944
load:0x40080400,len:6388
entry 0x400806b4
i have another code working for esp32cam and send image to telegram... maybe any can show why works there and not here please.
here the config
Hello, I need help with this code to show the longitude and latitude from the neo6m module. When the map is displayed, it looks very close. How can I fix it?
It is for a university project I hope you can help me thanks
code:
lat = thingSpeakRead(1962341,'Fields',3,'ReadKey','ZHIVMUHTJXI4xxxx','NumPoints',10,'Timeout',50);
lon = thingSpeakRead(1962341,'Fields',4,'ReadKey','ZHIVMUHTJXI4xxxx','NumPoints',10,'Timeout',50);
geoscatter(lat,lon,'h');
geobasemap('satellite');
Hello!
The fields sometimes will update most of the times but not always. The Serial monitor shows the following output when it does not update:
while when it update it shows the following:
There is no issue with the update rate since it is more than 15 seconds.
Iam using a feather fona and the chunk of the code Iam using to send the data is the following:
if (gprsSerial.available())
Serial.write(gprsSerial.read());
gprsSerial.println("AT");
delay(1000);
gprsSerial.println("AT+CPIN?");
delay(1000);
gprsSerial.println("AT+CREG?");
delay(1000);
gprsSerial.println("AT+CGATT?");
delay(1000);
gprsSerial.println("AT+CIPSHUT");
delay(1000);
gprsSerial.println("AT+CIPSTATUS");
delay(2000);
gprsSerial.println("AT+CIPMUX=0");
delay(2000);
ShowSerialData();
gprsSerial.println("AT+CSTT=\"internet\"");//start task and setting the APN,
delay(1000);
ShowSerialData();
gprsSerial.println("AT+CIICR");//bring up wireless connection
delay(3000);
ShowSerialData();
gprsSerial.println("AT+CIFSR");//get local IP adress
delay(2000);
ShowSerialData();
gprsSerial.println("AT+CIPSPRT=0");
delay(3000);
ShowSerialData();
gprsSerial.println("AT+CIPSTART=\"TCP\",\"api.thingspeak.com\",\"80\"");//start up the connection
delay(6000);
ShowSerialData();
gprsSerial.println("AT+CIPSEND");//begin send data to remote server
delay(8000);
ShowSerialData();
delay(4000);
gprsSerial.println(str3);//begin send data to remote server
delay(8000);
ShowSerialData();
delay(6000);
gprsSerial.println((char)26);//sending
delay(6000);//waitting for reply, important! the time is base on the condition of internet
gprsSerial.println();
ShowSerialData();
gprsSerial.println("AT+CIPSHUT");//close the connection
delay(3000);
ShowSerialData();
delay(3000);
}
Thank you in advance!
Using a Thingspeak42 node with NodeRed on a RaspberryPi 4. The node is showing data is being sent but nothing gets populated on graph in Thingspeak.
I would like to have a widget to control a pump connected to Thingspeak via Talkback. I have also established a connection with thingspeak where I publish my sensor data to the channel and can visualize the data through the various widgets. But I cant find a widget or method to control the pump from a graphical perspective on the channel (like a switch or button interface where clicking them would turn the pump on or off). Thingsboard seems to have the feature, not sure of thingspeak. If anyone knows a way please do comment out. Have a great day!
lorawan, MQTT,
Hi,
I use micro:bit and iot:bit to collect data about temperature and humidity (via BME 280, but I cant connect with ThingSpeak, but Iam connected on wifi.
What I make wrong?
Hi all
Learning home automation and found your webpage via cookbook sample code, which I cannot get work, i.e. sending a tweet. Somehow API keys should be OK as I got another sample from your page (bulkdata upload with Raspi) working just fine
Code seem to run and response is OK 200, am I just missing how to check this from twitter or? if I change API key to xxx response is 400 so
import time, os
import requests
MAX_TEMP = 19.0
MIN_T_BETWEEN_WARNINGS = 1 # Minutes
BASE_URL = 'https://api.thingspeak.com/apps/thingtweet/1/statuses/update/'
KEY = 'xxx'
def send_notification(temp):
status = 'Thingtweet: Room getting hot. room temp=' + str(temp)
data = {'api_key' : KEY, 'status' : status}
response = requests.post(BASE_URL, json=data)
print(response)
print(data)
def room_temp():
f = open('/mnt/1wire/28.55CA95F0013C/temperature','r')
room_temp = f.read()
return float(room_temp)
while True:
temp = room_temp()
print("room Temp (C): " + str(temp))
if temp > MAX_TEMP:
print("room TOO HOT!")
send_notification(temp)
print("No more notifications for: " + str(MIN_T_BETWEEN_WARNINGS) + " mins")
time.sleep(MIN_T_BETWEEN_WARNINGS * 1)
time.sleep(10)
an undergraduate student
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7627 票
i have imported data from a chanel, edited it and re uploaded again,
it returns error message when i upload it.
it says "The uploaded file was not imported because it is empty"
Mathworks returns also a message to my email saying "Timestamp already in channel."
Hello,
Can someone please give me a hint how the settings at Tasmoto have to be made in order to send data via MQTT to ThingSpeak.
Halil Kemal has an open channel tag: tasmota where this seems to work.
Thank you in advance for your support.
TOM
I've now seen linear programming questions pop up on Answers recently, with some common failure modes for linprog that people seem not to understand.
One basic failure mode is an infeasible problem. What does this mean, and can it be resolved?
The most common failure mode seems to be a unbounded problem. What does this mean? How can it be avoided/solved/fixed? Is there some direction I can move where the objective obviously grows without bounds towards +/- inf?
Finally, I also see questions where someone wants the tool to produce all possible solutions.
A truly good exposition about linear programming would probably result in a complete course on the subject, and Aswers is limited in how much I can write (plus I'll only have a finite amount of energy to keep writing.) I'll try to answer each sub-question as separate answers, but if someone else would like to offer their own take, feel free to do so as an answer, since it has been many years for me since I learned linear programming.
How can I export data other than downloading it as a CSV file?
I want to embed the graphs in a website, how can I do that?
OR
How can I export data and display it on my own in the website?
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MATLAB Central Team
