Dalaman is nice. Glad you liked it. Thanks for the advices again.
David I am in trouble again. I am working on this project running on Nextion 3,2" display. I managed to send the Hum and temp values to Nextion with the codes below. I also want to activate gauges showing the same value on gauges however Arduino IDE returns the following failure;
myNextion.setComponentText("temperature", String(x, 1));
myNextion.setComponentText("humidity", String(y, 1));
myNextion.setComponentValue("temp_gauge", String(x));
myNextion.setComponentValue("hum_gauge", String(y));
Note that the code is running just fine if I delete the last 2 setting value lines above !
D:\NebatHydro\Arduino\TFT LCD\NebatLab\dht21\dht21\dht21.ino: In function 'void loop()':
dht21:44: error: no matching function for call to 'Nextion::setComponentValue(const char [11], String)'
myNextion.setComponentValue("temp_gauge", String(x));
^
D:\NebatHydro\Arduino\TFT LCD\NebatLab\dht21\dht21\dht21.ino:44:54: note: candidate is:
In file included from D:\NebatHydro\Arduino\TFT LCD\NebatLab\dht21\dht21\dht21.ino:12:0:
C:\Program Files (x86)\Arduino\libraries\nextion-master/Nextion.h:73:11: note: boolean Nextion::setComponentValue(String, int)
boolean setComponentValue(String component, int value);
I am too idle to read the Nextion docs. I would guess that the setComponentValue() requires a special kind of String() method.
If x is a float, you might need a precision e.g. you don't want any decimals
myNextion.setComponentValue("temp_gauge", String(x, 0));
myNextion.setComponentValue("hum_gauge", String(y, 0));
Seriously, it is your job to read documentation for your project.
David.
I can't resist to try to help.
The compiler already tried to help you:
C:\Program Files (x86)\Arduino\libraries\nextion-master/Nextion.h:73:11: note: boolean Nextion::setComponentValue(String, int)
boolean setComponentValue(String component, int value);
So you should take the advice and try:
myNextion.setComponentValue("temp_gauge", x);
myNextion.setComponentValue("hum_gauge", y);
if x and y are the values to present.
If the compiler still complains:
myNextion.setComponentValue("temp_gauge", int(x));
myNextion.setComponentValue("hum_gauge", int(y));
Thanks David, I am a beginner (as beginner as one can be. I was just a skipper before 
) I will someday understand those documentation but now I am just following logical steps and worked so far. When it doesn't, fortunately you can't resist not to help
Anyway, your advise worked. Now both values and gauge needles are working like crazy. Now the problem is they are working too crazy that they blink. I add a delay but not helping. The % and °C texts dissappeared. Nothing was assigned to them and they re appear if I erase the set value for gauges lines.
Not asking just stating the progression 
all advises much appreciated
I have never used Nextion. And have never read the Nextion docs.
I just assumed that there must be a myNextion.setComponentText(String, String) method if your temperature statement works. i.e. you convert the float value to a formatted String.
But there is probably a myNextion.setComponentText(String, int) method too. An int does not need formatting.
It is your job to Google for the Nextion docs.
Having overloaded methods in C++ is handy from one point of view. But you have to look up exactly what arguments are required for each variant.
In C you would just give a descriptive name for each specific function. e.g. setComponentText_int(char *, int)
There are many Nextion users. Please paste/attach complete sketches that show your problem if you want people to give accurate replies.
David.
Thank you David.
setComponentText(String, String);
and
setComponentValue(String component, int value);
look similar, but are different!
And they do have meaningful names.
Oops. My eyesight was not very good !
It also demonstates how it is unwise to reply to subjects that I am not familiar with.
David.