結果:
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Hopefully you are aware that MATLAB is built into ThingSpeak. Right now, MathWorks is hosting two contentsthat can help you learn MATLAB and then improve your IoT project.
I just set a calendar reminder to do a Cody problem each day. I can't win a prize but I can still get a virtual badge if I get a streak going.
hello :
I'm success using http send/receive between 16 bits MCU and Thingspeak.com via wifi , lan (ESP32(wifi) and LAN module )
but recently I have a new device it's BC95-B8 NBIOT device from quectel which it can only use UDP mode.
I want to connect / send /receive data with Thingspeak.com . but can't find any knowledge explain how to
Please advise
Thanks
I am working on a LoRaWAN project. My setup consists of 100 or more end-devices talking to a network server through a single gateway (private). My problem now is this.
I want the end-devices to belong to one of four groups with each group having a fixed range of spreading factors that can be used. Eg group 1 can only use SF 12, group 2 can only use SF 7, and so on. When an end device sends a join request, the network server should know which group the end device belongs to so it can assign the correct transmission parameter.
How can I achieve this? How can I encode the group that each end device belongs to into the join request for the network server, using maybe the AppEui or DevEui or AppKey or something? Any ideas?
Hello, I run a weather station that consists of several sensors. Sensor1 supplies external weather data, Sensor2 internal room data and Sensor3 particulate matter values.
Can I display the variables of all sensors in a "Weather Station" channel and display them in charts?
If so, how do I do that with ThingSpeak?
Many Thanks
Hi Fellow Users,
I am Muthuserpi From A begginer of Optics studio Please anyone help me how to add two diffeaction reflective grating and How to tilt and decenter in matlab simulation
Thanks And Regards
S.Muthuserpi
Just in case, I have my license of MATLAB. I just have this question and I didn't find any information. I wouldn't like to create another account, for this reason I prefer to ask here.
Uniform spacing and the problem of round-off error
The vector [3 4 5 6 7 8 9] is uniformly spaced with a step size of 1. So is [3 2 1 0 -1 -2] but with a step size of -1.
The vector [1 2 4 8] is not uniformly spaced.
A vector v with uniform spacing has the same finite interval or step size between consecutive elements of the vector. But sometimes round-off error poses a problem in calculating uniformity.
Take, for example, the vector produced by
format shortg
v = linspace(1,9,7)
v = 1x7
1 2.3333 3.6667 5 6.3333 7.6667 9
Linspace produces linearly spaced vectors but the intervals between elements of v, computed by diff(v), are not identical.
dv = diff(v)
dv = 1x6
1.3333 1.3333 1.3333 1.3333 1.3333 1.3333
dv == dv(1)
ans = 1×6 logical array
1 0 0 1 0 1
diff(dv)
ans = 1x5
4.4409e-16 0 -4.4409e-16 8.8818e-16 -8.8818e-16
Some extra steps are therefore necessary to set a tolerance that ignores error introduced by floating point arithmetic.
New in R2022b: isuniform
Determining uniformity of a vector became a whole lot easier in MATLAB R2022b with the new isuniform function.
isuniform returns a logical scalar indicating whether vector v is uniformly spaced within a round-off tolerance and returns the step size (or NaN if v is not uniform).
Let's look at the results for our vector v,
[tf,step] = isuniform(v)
tf = logical
1
step =
1.3333
How about non-uniformly spaced vector?
[tf,step] = isuniform(logspace(1,5,4))
tf = logical
0
step =
NaN
Give it a shot in MATLAB R2022b
- What happens when all elements of v are equal?
- Can you produce a vector with uniform spacing without using colons or linspace?
- What additional steps would be needed to use isuniform with circular data?
References
- isuniform - documentation
- Floating point numbers - documentation
- Floating point numbers - Cleve's Corner (blog)
This article is attached as a live script.
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Hello Community,
For E vehicle application to control the speed and torque of PMSM motor I am implementing FOC algorithm. We know that to arrive at Speed set point we have speed control loop which is outer loop, Further PI CONTROLLER of speed loop will give reference for Iq current which regulates the current using current loop. My question is 1.How to arrive at Torque set point?
2. Is speed control using FOC is enough or we should implement Torque control algorithm also?
3. should we have speed mode and Torque mode selection in case of constant speed requirement during cruise mode and high torque requirement during uphill situation respectively
4. To arrive at Torque set point what is the relation or transfer function to tune PI controller for Torque loop?
Please give your valuable inputs and answers, thanks in advance
I wanted to ask that can we send bulk data through ThingSpeak ESP32 library using:
POST /channels/266256/bulk_update.csv HTTP/1.1
Host: api.thingspeak.com
Content-Type: application/x-www-form-urlencoded
time_format: relative
I saw it on mathswork "Bulk-Write CSV Data" (link: https://www.mathworks.com/help/thingspeak/bulkwritecsvdata.html)
Does ThingSpeak library supports the capability to send bulk csv data, any guidance?
Thanks and looking forward for your positive reply
Maybe %lld instead of %d?
I would like to know the maximum amount of storage space in the Data Logger.
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I have a data.
And, I want to substract the data using for.
But, I want to ignore the nan values and substract others.
For example, [1, 2, 3, NaN, 6, 9, 12, 14] ---- substract---> [1, 1, 3, 3, 2]
How can I do this?
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Hi guys,
I'm very new to matlab, so this might a rookie mistake. However, it seems that I have messed up some important part with the plot function. The program does not give my any kind of error messages, but still does not plot anything. What can I have done wrong and how do I fix this?
Best regards
My code:
close all
for t = -2:0.1:3
if (t<0 || t>1)
xvalue = 0;
end
if (t<= 1 && t>= 0)
xvalue = exp(2*t+1);
end
yvalue = -1*(xvalue) + exp(1);
hold on
figure(1);
plot(t, yvalue);
hold off
end
grid on;
Help us please, we need to send email after measurement from sonde (GSM report) is under limit for three days.
"React" on the limit, is non for three days under limit., and time control is days or weeks runner.
I propose trigger on time control but what is the code?
????
% Read the recent data.
moistureData = thingSpeakRead(channelID,'NumDays',3,'Fields',1); {is that right, that I read last three days measurement (3000x)?}
% Check to make sure the data was read correctly from the channel.
if isempty(moistureData)
alertBody = ' No data read from plant. ';
else
%{need if
% moistureData is for three days under limit from sonde then send
% email}
span = max(moistureData) - min(moistureData);
dryValue = span;
% Get the most recent point in the array of moisture data.
lastValue = moistureData(end);
% Set the outgoing message
if (lastValue<=dryValue)
alertBody = ' I need water! ';
elseif (lastValue>dryValue)
alertBody = ' No water needed. ';
end
really thanks so much
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