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 »

Is it only CS pin which needs to be separate pin?
My solution also uses 2" tft displays & 2,4" displays, all with different number of pins.
E.g. should DC and CLK also have separate pins then?
And can RST be reused across all types of displays?

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

Post by adaloop »

I no longer use the "fast" library. I only use the "Adafruit_ST7789.h" library now.

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

Post by adaloop »

According to the 2560 documentation then the following pins are for SPI connections:
pin 50 is MISO
pin 51 is MOSI
pin 52 are CLOCK and
pin 53 are SS or CS

I already use those for my 2" display, but I also need to connect several of your 1.9 displays.

So when u write to change the CS pin to something individual for each display, what pins can I then use?

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

Post by adaloop »

Also one of the received Adafruit 1.9" TFT displays are skewed at delivery and not put correct in x,y coordinate on the PCB.
How can I get it changed?
Attachments
IMG_20230222_111901 adafruit display skewed, bug, 800px.jpg
IMG_20230222_111901 adafruit display skewed, bug, 800px.jpg (186.39 KiB) Viewed 150 times
IMG_20230222_111840_ adafruit display skewed, bug, 800px.jpg
IMG_20230222_111840_ adafruit display skewed, bug, 800px.jpg (174.38 KiB) Viewed 150 times

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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 »

Is it only CS pin which needs to be separate pin?
Yes. This relates to how SPI works, which is not TFT specific.
My solution also uses 2" tft displays & 2,4" displays, all with different number of pins.
E.g. should DC and CLK also have separate pins then?
Yes. In addition to the main SPI link, there are TFT specific additional pins, like DC. These will also need to be unique for each display.

However, CLK should most likely be the SPI CLK pin? In that case, see previous question. That can be shared.
And can RST be reused across all types of displays?
Yes
So when u write to change the CS pin to something individual for each display, what pins can I then use?
Same general answer as above. SPI shares MOSI, MISO, SCLK pins with all devices on the SPI bus. But each device must have a unique CS pin. If, in addition to SPI, devices (like TFT's) have additional pin requirements (DC has nothing to do with SPI), then those must also be dealt with accordingly.

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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 »

For the crooked TFT - that seems to be something that can happen in shipping. We've seen it with other similar products. An FAQ was written for TFT Feathers to cover this here:
https://learn.adafruit.com/adafruit-esp ... aq-3134469

That same general guidance should apply here as well.

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

Post by adaloop »

Thanx for your answers. I'l try your guidances.

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

Post by adaloop »

Pls. also answer my question on comment: viewtopic.php?p=963009#p963009

And my question about 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?

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

Post by adaloop »

What are the SDCS and Lite pins for?

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

Post by adaloop »

Which data/commands/interrupts are the tft slave sending back via the MOSI pin?
E.g. tft.flush()? tft.availableForWrite()? and/or others?
And how can we react on it? or how is it intended to use?

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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 »

In your guide u write use "3-5v Vin" OR "V+"
But on your pcb there is no such labels, only "Vin" and "3V"
Please link to the specific Learn Guide page that has this information.
Also - all guides have a Feedback option (link in left hand nav) which can be used to report back any issues with Learn Guide pages.
And my question about which pins can then be used for distinguised CS & DC for extra displays?
Any available GPIO pin.
What are the SDCS and Lite pins for?
Please see product guide for pinout information.
Which data/commands/interrupts are the tft slave sending back via the MOSI pin?
E.g. tft.flush()? tft.availableForWrite()? and/or others?
And how can we react on it? or how is it intended to use?
No information is sent from the TFT on the MOSI pin. The MOSI pin only carries information from the host controller to the TFT. This is how SPI works and is nothing unique to the TFT.

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

Post by adaloop »

►It was in the product link you wrote to me. (https://learn.adafruit.com/adafruit-1-9 ... iring-test)

►I dont know what GPIO is. Could u be more specific which intervals are usable?

►That are exactly the 2 pins on your display-pcb which are not described in your product page, thats why Im asking.

►Sorry I wrote wrong, I ment from the MISO pin?

And if not sending anything, does that mean that tft.flush() & tft.availableForWrite() will not work?

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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 »

►It was in the product link you wrote to me. (https://learn.adafruit.com/adafruit-1-9 ... iring-test)
It is referring to the Vin pin on the TFT breakout. The 3-5V part is possibly confusing, but is simply restating the input voltage range for that pin.
►I dont know what GPIO is. Could u be more specific which intervals are usable?
GPIO = General Purpose Input/Output. You can think of these as digital pins - pins that can be set HIGH or LOW. Other than special pins like power and reset, most pins can do digital in/out. You'd want to reference the pinout specific to the Arduino board you are using for more details.
►That are exactly the 2 pins on your display-pcb which are not described in your product page, thats why Im asking.
Can you link to the page where the information is missing?
Both SDCS and Lite are described here:
https://learn.adafruit.com/adafruit-1-9 ... ns-3113297
►Sorry I wrote wrong, I ment from the MISO pin?
This question is still confusing. In general, you don't need to worry about the lower level SPI traffic. Like what's actually being sent/received on the SPI data lines. Instead, use the library methods. The basic TFT library is what is shown here:
https://learn.adafruit.com/adafruit-1-9 ... iring-test
The GFX library provides higher level drawing features:
https://learn.adafruit.com/adafruit-1-9 ... fx-library
And for displaying bitmaps, the info is here:
https://learn.adafruit.com/adafruit-1-9 ... ng-bitmaps

Where are you seeing a reference to flush() and availableForWrite() ?

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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'll repeat my original question then:
adaloop wrote: Thu Mar 02, 2023 3:31 pm There is a mismatch in your guidance link about the pins and the actual text on the TFTs pcb!
In your guide u write use "3-5v Vin" OR "V+"
But on your pcb there is no such labels, only "Vin" and "3V", so theres a conflicting disturbance there. So what is what? What should be connected to what?

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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 then:
adaloop wrote: Fri Mar 03, 2023 7:05 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?
Last edited by adaloop on Sun Mar 05, 2023 2:59 pm, edited 1 time in total.

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