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4-pin connector too close to the edge...

A little note...

The UART interface connector is located too close to the edge of the board. When the installation of the display in the housing, I must to leave a gap of at least 5 mm or more from the edge of the display to the wall of the case. This increases size of case and adds a border around the active display area, which is not always looks harmonious. In compact housing I compelled fluster the wires to the connector (see photo).

I propose to move the interface connector away from the edge.



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So why didn't you just position the Nextion display so that the connector faced the MCU instead of the wall?

Nextion Editor settings for the display supports 180° orientation.

I support this idea as well. I had to print an extension on my bezel to accommodate this. would be easier if the connector was turned 90 degrees.

For the record, the request will be represented.

Because the TFT display has a definite direction in which the color distortion is minimal. I brought a photo which obviously, I look at the display on the top. If it used the ISP matrix, the problem would not exist.

I can change the angle of the display. But if I look at it perpendicularly, then due to the fact that the device placed below eye level, the display will reflect glare from light sources.

So as stated, the request will be represented and has been recorded. 


Until such decision, user's solutions will need to take the size and space

of the connector into consideration at design time of the enclosures.


We will report again when there is anything to tell.

OK, thank you.


And since in this thread we are talking about the new revision PCB, I note another problem...

Power to the display comes from the USB through PTC resetable fuses (MF-NSMF110), through p-chanel MOSFET (IRLML6401) and through the inductor (LQM21PN4R7NGRD). The resistance of the power supply circuit can reach up to 0.48 Ohms. When the display current is 250 mA, the voltage drop is 0.12 V. And the starting current is much higher! Plus the consumption curent of the control circuit. I must very picky to choose of the supply USB cable. Example: if I use a USB cable with 28AWG power lines and 1 m length then display does not start! Consumption curent of the all device yet is only 300 mA.


I suggest expanding the range of supply voltages down to 4...4.2 V.

And display is very very noisy on power!


Okay, I'm done with criticism :) Overall, the project is very good. Well done!

isn't this a reason, why we recommend a stabilized external 5V 1/2A power plug ...


honestly, when we talk about USB interfaces to use as plain power source, you must face the fact, that not every manufacturer who implement the USB interface is 100% USB specification conform ...


    - 5V can be in a range from 4.2 up to 5.3 V, I even already saw 5.8V ... and it is still called USB ...

    - USB 1.x states 500mA max. but this is not always the real truth, especially when a manufacturer use a cheap internal USB hub to give you the illusion of many USB ports ...

    - even the quality of your used cable will influence your connection ...


so, USB is among the most bad solution to drive such displays. It will work well for smaller ones, but the bigger they became, the less they will work well ...



Yes, but you must admit, for desktop and handheld devices powered by USB very convenient. Power supplies with current up to 2A can be found in every home. If any components in the device require a different supply voltage (not +5V), they can be connected to the step-up or step-down voltage regulator. But the requirement of stable +5V - a few ties the hands of the developer of such devices.

 

The USB 1.x and 2.0 specifications provide a 5 V supply on a single wire to power connected USB devices. The specification provides for no more than 5.25 V and no less than 4.75 V (5 V ± 5%) between the positive and negative bus power lines (VBUS voltage).


Even if it is convenient ... not every manufacturer implemnts things within specifications ... and that's something out of our control, what endusers finally may have and use ...


The best designed PCB won't help a lot, when the enduser just use the most cheap unshielded cables ... and to run your hardware always on its theoretical limits or even assume that a maximum theoretical limit can be used permanently can already be the reason why something just don't work as expected ...


You surely can design your PCB in a way, that most issues are handled, you also can use more accurate and low tolerant components ... and you can do this all very excessive and with open end ... but keep in mind, finally the end-user also must pay for this all ... and I have my doubts, that he will ...


So, the real magic is to find a good valued balance between your product itself and the price you can offer ...



Thank you for listening. My job is to offer )


Than limited to a lower threshold of power supply? By step-up converter for LCD matrix, or something else?

every request is taken seriousely ... but it is still the better and more universal solution, when the enduser just care a bit about the quality of power-sources he use ... because that's under his control ...

Getting back to the connector discussion... I had the same problem. 

What I ended up doing was desoldering the connector from the board, bending the pins a bit, and soldering it back into place so it pointed toward the rear instead of the side of the board.

It's not supported as well now but I think it'll be okay as long as I don't put too much force on it.  I wish the factory had done the connector that way to begin with!

 


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