Nextion reading a number or string from a object

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

Paulvk,
Thanks for your help, so presum that I use the get #1 command to retrieve the answer from the nextion, at some point need to clear the buffer ?

Thanks, Wayne

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

I get a compile error

Error : 44 Line : 30 2 variables expected , in File : D:\MCS\Programs\Nextion-Test\Read RTC-2.bas

print #2 , num_test.val=10

Num_test.val is the objname in Nextion it's a number Box

I tried to separate the and assign to variables, I don't get any errors but there is nothing coming back from Nextion.

dim _Num as string * 12
_num = "Num_test.val="

call nextion

Sub Nextion
Printbin #2 , &HFF ; &HFF ; &HFF
Waitms 100

End Sub

albertsm · Joined: 09 Apr 2004 Posts: 5922 Location: Holland

sending , num_test.val=10 is not ok.
i think you need to send the ID (a number).

you can use inputbin to read the input.

Paulvk · Joined: 28 Jul 2006 Posts: 1257 Location: SYDNEY

Ok have arrived somewhat unpacked.

Its best to start with a simple screen the button , text box and number box.
Then just write simple code to talk to the nextion.
Or do what I did first and use a terminal program , I used realterm with a rs232 to TTL adaptor on my PC
to send and receive commands its very suited to this as it has two send boxes
so you can keep the 0XFF 0XFF 0XFF in one and send it as a number while using
the other to send text commands .

Now there is really no advantage in "I tried to separate the and assign to variables"
if you do not want to write something many times in bascom you just assign it to a constant.

With the nextion if you create a button and under the touch press event you put prints "text001",0
the nextion should send text001 when you press the button you can then confirm if you have it
hooked up correctly I have a couple of rs232 to TTL units that had TX & RX marked the wrong way around
spent some minutes trying to work out why it was not working.

So best to confirm its working before trying to write a lot of code in bascom.

Regards Paul

Duval JP · Joined: 22 Jun 2004 Posts: 1161 Location: France

Hi
i just give you a small example

and I add a zip file with
- program
- tuto in PDF and powerpoint
- picture files
- HMI file
the video :https://youtu.be/7T40DF3LYvw

i you need help ,I'm back from vacation I'm rested!
Wink

JP

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

Thanks Duval JP,

I've been using Realterm and 2 MAX232CSE Modules to debug with , I noticed than in the send window from Nextion on the real term I was getting a CR and LF which was causing Nextion to not respond, after research I found that adding ; at the end of every print statement all started working, I think I'm on my way now I'm communicating with the Nextion very well now

Thanks, Wayne

Duval JP · Joined: 22 Jun 2004 Posts: 1161 Location: France

Hi rwlee,
I add the time, (the date will come from monday
I do step by step because a lot of people come crazy with nextion, me too !

I use slicer because is funny, you can use button or what you want

So As yesterday I add
- program
- tuto in PDF and powerpoint
- picture files
- HMI file
no video, i'have no time, but sure it works ! Wink

I must say RTC of Nextion is not so good as DS3231 , and it is an efemism
Again you mus dim your var as long not byte Idea

Duval JP · Joined: 22 Jun 2004 Posts: 1161 Location: France

Hi
I add the date today, again with nextion not so easy to read back the dates but the sub works well now
I hope it can help you

I clean the include "sub_macro_nextion_base.inc" , if you use it and found some mistake let me know

the video :
https://youtu.be/Lt85sGaZNOg

jp Wink

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

[quote="Duval JP"]Hi
i just give you a small example

Thanks again for the Info

Wayne

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

So I tested the output of the Display, and it works directly with the PC Terminal Emulator, to Print "Hello World" on the comport. But when I connected to the MCU I cant capture the input!

I even tried spliting the Serial output of the so the output of the Nextion display goes directly into the 328p But I get Nothing!

EDC · Joined: 26 Mar 2014 Posts: 971

It is a "classic mistake" Wink

For buffered Serialin you can`t forget to "Enable Interrupts"!
I know because, years ago, I take that lesson too Very Happy

ahahahahaha

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

Thanks, EDC

That did it, but I can't find any examples of how toput together as string extracted from each byte, Is there anyway to grab the entire string at once?

EDC · Joined: 26 Mar 2014 Posts: 971

You can try like that.. there is plenty of solutions.

rwlee · Joined: 04 Aug 2008 Posts: 36 Location: La Porte, Texas

So I'm Getting the entire Sring but its not formatting Correctly, I had to modify your code because I wasn't getting any thing.

EDC · Joined: 26 Mar 2014 Posts: 971

Previously I post a general receive routine for "typical" communication.
If you want to communicate with Nextion in both directions you must invest more time to learn Very Happy

Please look at my old post -> https://www.mcselec.com/index2.php?option=com_forum&Itemid=59&page=viewtopic&p=77756#77756

PS. Receiving weird characters it is often symptom of wrong baudrate. Nextion communicate at 9600 by default I think. Not yours 19200.