Gauge widget with matlab data
Pedro
on 17 Jan 2023
Latest activity Edit by Christopher Stapels
on 25 Jan 2023
Hi, what would be the best approach to use the gauge widget to display calculated data? I have a channel that displays a value that needs some math applied to it to give a correct value. I have a matlab visualization that converts this value into what I need and plots it. However, i believe a gauge is more appropriate than a plot and it seems the matlab "uigauge" object does not work for thingspeak.
Is there a way for the gauge widget to show my data coming out of the matlab script?
Thanks!
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There is a Gage widget built into thingSpeak. On the channel view, select Add Widget, and choose the gage widget. Select the channel, field, and propoerties of the gage widget and the channel where you want it to be displayed. See the widget help for more info.
Hi Christopher, thank you for the feedback. I understand that there is a built in feature for that, but it seems seems like it only works for data from the fields that I publish. I wanted to have a gauge to show the result of a matlab script.
Say if a channel publishes a 0-100 value, but I use matlab to conver it to a value between 5-35. How could I add a gauge for that?
Are you using desktop MATLAB, or MATLAB analysis/viz in ThingSpeak? Either way, after the conversion, you can write back to a new channel and set the gage to read from that new channel.
You can also write code in MATLAB to generate a gage visualization for you. A polar plot makes a good start.
I mean in MATLAB analysis/viz in ThingSpeak. In regular MATLAB I can create a gauge with uigauge with no issues. I just wanted to see if I could do the same in ThingSpeak but it seems like I will have to write to a different channel.
Most UI elements arent allowed in ThingSpeak due to the interface. I have some fairly medium quality gage code that would work in a MATLAB viz, Ive been meaning to post it on file exchange. Thanks for the push. Would something like this work for you? Its a MATLAB function you can run in ThingSpeak to make a gage in a MATLAB viz
Absolutely! Thanks for your help!
Im not going to get around to putting this on File exchange becasue its too sloppy of a solution, but if it works for you, here is the silly function I wrote (be careful if you use small numbers, the rounding will kill it).
% Sample call
mygage(475,1,3000,0,1200,1200,1800,1800,2800,25);
function MakeGage = mygage(value, lowRange,highRange,greenLow,greenHigh,yellowLow,yellowHigh,redLow,redHigh,nTicks)
% TODO range cannot be less than 1 due to rounding
fullRange = highRange - lowRange;
greenStart = 230 - (360-80) / fullRange * (greenLow - lowRange);
greenEnd = 230 - (360 - 80) / fullRange * (greenHigh - lowRange);
yellowStart = 230 - (360 - 80) / fullRange*(yellowLow - lowRange);
yellowEnd = 230 -(360 - 80) / fullRange * (yellowHigh - lowRange);
redStart = 230 - (360 - 80) / fullRange * (redLow - lowRange);
redEnd = 230 - (360 - 80) / fullRange * (redHigh - lowRange);
tickMove = fullRange / nTicks;
green = [greenStart:-5:greenEnd];
green = green*2*pi/360;
rgreen = ones(1,size(green,2));
polarplot(green, rgreen,'g','LineWidth',16);
hold on
yellow = yellowStart:-5:yellowEnd;
yellow = yellow*2*pi/360;
ryellow = ones(1,size(yellow,2));
polarplot(yellow, ryellow,'y','LineWidth',16);
red = redStart:-5:redEnd;
red = red*2*pi/360;
rred = ones(1,size(red,2));
polarplot(red, rred,'r','LineWidth',16);
valueAngle = 230 - (360-80) / fullRange * (value - lowRange);
rblack = [0:0.1:1];
black = valueAngle * 2 * pi/360 * ones(1,size(rblack,2));
polarplot(black, rblack,'k','LineWidth',5);
ax = gca;
ax.RTickLabel = [];
ax.RGrid = 'off';
width = 280 / nTicks;
tickHold = 0:width:280;
tickHold = tickHold-50;
tickHold = [tickHold(tickHold>=0),tickHold(tickHold<0)+360];
ax.ThetaTick = tickHold;
%ax.ThetaTick=[0:width:230,310:width:360];
tickLabels = round([highRange:-tickMove:lowRange],0);
shift = round(50 / width);
tickLabels = circshift(tickLabels,-shift);
ax.ThetaTickLabel = tickLabels;
ax.RLim = [0,1.05];
text(265*2*pi/360,0.8,string(value),'fontSize',20);
hold off
end
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