I share your frustration at this response, however despite not liking (or wholly agreeing with) the response I must respect that thier stance is clear. It won’t be addressed. Thier assertion regarding the indeterminate state of GPIO’s for any any microcontroller or microcontroller based system on startup isn’t “wrong”. That is in fact the norm and as you point out, can and should be addressed in the power on initialization sequence.
I would hasten to add that as this appears (at least to me) to be related to the HMI system formware, presumably executed at startup, I find it highly unlikely that changing code in the Nextion editor will have any positive impact on the observed behaviour. Recall that the output of the editor is in itself a program that is loaded by the system post startup initialization.
I am curious. In your response you point out that Nextion has what appears to be a regular firmware release schedule. I am unaware of this firmware location and the steps required for blowing it into the HMI. Perhaps you can share that information? Please feel free to DM me or email to firstname.lastname@example.org.
Like you, I am disappointed by the response. I now have an ‘Intelligent’ series module that I can’t use for my intended application without jumping through some admittedly minor hoops related to external circuit design. Holding off the supply rail for some period of time is a viable fix but one I’d rather not have to go through. I did suggest to the person at Nextion that responded to my support request that they explicitly document this behavior. That person stated they were to fix thier documentation by being more explicit about the electrical characteristics of the pins (a good step forward). Simply describing, however accurately and detailed it may be, the electrical characteeristics of the GPIO on startup doesn’t really “tell the story” to those in the audience that aren’t electronics engineers disciplined in the nuance of circuit behavior in microcontrollers or systems based on them. It would have been a further step forward to, perhaps, use my situation as an opportunity to ‘educate’ non-professional users regarding this specific circumstance.
That appears unlikely.
As you point out (as I may have), dropping back to the Enhanced display is a viable solution. I don’t need the more advanced capabilities that the ‘Intelligent’ series provides but I do need all eight of the GPIO’s.
I’m still internally debating how much effort I want to go through for what was going to be a short project and accompanying article for QST. If I decide to move forward I’ll be quite specific about what I encountered and shall do so in a fair and as far as is possible, objective way.
I’ll close with this:
I found the Nextion HMI to be an ideal component for my use case. It appeared to tick many boxes that neatly address issues faced by electronics hobbyists. Digging in revealed what I considered to be a significant issue. Getting the attention of Nextion support was not a simple task and the resulting response was less than satisfying. Conside that they have never (at least to my knowledge) held thier product out as something an hobbyist would find suitable for use. Indeed, if you look at thier support site they are quite specific (perhaps adamant) that “Reading of the documents/forum topics for Nextion understanding is a must. Not understanding Nextion does not make a Level 2 Hardware issue.”
Thier assertion, quite simply put, is that this behavior is not abnormal and thus is not a “Level 2 Harware issue”.
Imagine how ‘bent’ I’d be if I spent several thousand dollars on a number of Intelligent HMI’s for a ‘real product’, discovered what I found to be a “Level 2 Hardware” issue, reported it to the vendor then was informed that this was in fact ‘normal’ behavior. My boss would probably look at me sideways and wonder if he hired the wrong person.
So, do I:
1 - Retain the Intelligent HMI module and redesign the external GPIO circuitry
2 - Swap the Intelligent for an Enhanced HMI module
3 - Completely re-factor the project to use a different approach
4 - Chuck it all and put a bunch of toggle switches and LED’s in place to control the station gear and call it a day
No matter what, the marketplace is full of interesting parts and companies that are interested in actively supporting ‘hobby grade’ users like me.
Thanks for reading this far. Good luck to the rest of you using the Nextion components. They appear to be good, useful devices with a number of appealing features. In my opinion thier support isn’t one of those features.
I’ll not get into any back and forth with Nextion. I reported the issue, they responded, end of story.