Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

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adaloop
 
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Re: Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

Post by adaloop »

I will also repeat this question:
adaloop wrote: Sun Mar 05, 2023 5:41 am if your solution are not sending anything back via MISO, does that mean that tft.flush() & tft.availableForWrite() will not work? and how can u then know if your TFT is ready for write and if/when its finish with writing?

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Re: Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

Post by adafruit_support_carter »

These questions have been answered. Not sure what more information can be provided.

The text "3-5V Vin" in the guide is referring to the Vin pin. It has a few extra character "3-5V" and also mentions an alternate name "V+". Please ignore the extra text "3-5V" and "V+". The Vin pin is the pin with the "Vin" label next to it here:
vin.png
vin.png (184.08 KiB) Viewed 113 times
Which pins can then be used for distinguised CS & DC for extra displays?
Is it 22+24+26+28+30..43+47..49? or which intervals?
There is no single answer for this. It is up to you to determine this for your setup and Arduino board being used. You will need to use the pinout information for the Arduino board you are using to determine this. If those pins are not being used for anything else, are broken out on headers pins on the board, and can function as General Purpose Input/Output, then *any* of them could be used for CS and DC.
does that mean that tft.flush() & tft.availableForWrite() will not work?
These functions do not exist in any of the referenced libraries, so will not work. More information about where these function are being referenced was requested in previous post.

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Re: Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

Post by adaloop »

adafruit_support_carter wrote: Sun Mar 05, 2023 3:27 pm The text "3-5V Vin" in the guide is referring to the Vin pin. It has a few extra character "3-5V" and also mentions an alternate name "V+". Please ignore the extra text "3-5V" and "V+". The Vin pin is the pin with the "Vin" label next to it here:
vin.png

Well, I ended up just putting 3,3v to the 3v pin and that worked apparently.

So should I understand it like this: It doesnt matter which of them I conect power to?
3v can only receive 3v, while the Vin can receive 3-5v?
What does "Vin" stand for? Variable input?
And why have 2 pins, if everything just could be connected to the Vin pin?

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adaloop
 
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Re: Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

Post by adaloop »

adafruit_support_carter wrote: Sun Mar 05, 2023 3:27 pm
Which pins can then be used for distinguised CS & DC for extra displays?
Is it 22+24+26+28+30..43+47..49? or which intervals?
There is no single answer for this. It is up to you to determine this for your setup and Arduino board being used. You will need to use the pinout information for the Arduino board you are using to determine this. If those pins are not being used for anything else, are broken out on headers pins on the board, and can function as General Purpose Input/Output, then *any* of them could be used for CS and DC.
The pins I have listed is based on what I understood on the 3rd diagram on this page: https://community.element14.com/product ... s-and-more

So can you concur that the above list is the ones which are free and available for CS connections for multiple displays?

Or question/answer in another way: Can I just try & error on the different pins? Or can I risk to harm either the Arduino or the display?

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adaloop
 
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Re: Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

Post by adaloop »

adafruit_support_carter wrote: Sun Mar 05, 2023 3:27 pm
does that mean that tft.flush() & tft.availableForWrite() will not work?
These functions do not exist in any of the referenced libraries, so will not work. More information about where these function are being referenced was requested in previous post.
Those commands drop down as suggestions in the Arduino IDE when you write the name of a TFT instance.
Researching further os this shows that it seems to be inherited from the basic serial class.

So my assumption was according to the SPI communications digram and that you wrote on your productpage that the MISO are not being used, then it doesnt have any communication back again from the TFT and therefore I would guess that the 2 functions doesnt work with your TFT!?

Is that correct understood?

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Re: Data sometimes lost when sending to ST7789V TFT-display with Adafruit_ST7789.h lib - Why?

Post by adafruit_support_carter »

So can you concur that the above list is the ones which are free and available for CS connections for multiple displays?
yes
Is that correct understood?
yes

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