buydisplay 1280 X 400 TFT ra8876 AND SSD2828 SPI connectivity

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Okay, glad you saw that first hand ...I could not identify where the message was coming from ..Still no change , can't write anything to display on the screen ....Hopefully someone will chime in.
 
I have a scope I'll check the SPI out .... I've just not been able to get to it yet .. I'll post an update...
 
I'm able to trigger the "2D ready failed" with a low voltage on the 5v rail. Could that be an issue for you?
 
Thanks for your reply .. Im building up a new supply for my project and will make sure I have sufficient current ...but I did drive it off a supply that could provide 1.5amps .....but I did check the power regulation and the dropout was too high .. I was down to 4.5v and I suspect it failed to operate ..bad regulator .....im building up a more robust supply this weekend .. so will let you know sometime tomorrow ..
 
No happyness, Built the new supply .. voltage and current are good under load ... Ran an RA8875 off the supply with a teensy 4.1 to test .. all good .... no issues ..

reconnected the ra8876 display .. confirmed wiring ... Current and voltage load are fine ) Compiled and loaded your test example ... No activity other then the backlight coming on ... This is tough, can't figure out for the life of me what I missed.

Will pull my scope out of storage ... and check the spi and see what's going on .. If the program is running it should be spewing data on the SPI line
 
Well tried both displays .. Not pulling my hair out yet .. but no luck yet .. This should be running ...but I'm missing something and just have not figured it out yet... LOL

will keep trying .. power is good , connections are good .. code compiles fine .. uploads fine, backlight is enabled when booted ..but won't write to the screen...
 
blackketter .... I'm at the point I had best take your wiring trace ... I was hoping I would not have to ask you this but , Something is not right ..

Thanks
K
 
Okay update .. I switched from the t4.1 to the t4.0 .. I re-did the configuration jumpers a second time ... I have torn graphics on the screen ..colored lines and they appear to be changing periodically so I suspect its the teensy executing the graphics routines ... closer but not quite there yet .. I pushed the ssd2828 connections to pins 23/22/21/20 on the teensy 4.0 ..

So I am closer now ...

note I tried it on the t4.1 and no output at all .. so not sure what's going on there..
 
I'm running on the t4.0 , the code appears to be running , display is trying to work , lines across the display , I'm currently using this pinout configuration with the T4.0
// Pin connection mapping
ER_TFT0784_t3 tft = ER_TFT0784_t3(
// Teensy pin // Display pin
10, // RA8876 CS 5
14, // RA8876 RESET 11
11, // RA8876 MOSI 7
13, // RA8876 SCLK 8
12, // RA8876 MISO 6
23, // SSD2828 CS 31
22, // SSD2828 RESET 43
21, // SSD2828 SDI 34
20 // SSD2828 SCK 35
);

I am running your example .. But need to sort out why the screen is torn ..open to suggestions
I played with the SPI clock and no difference..

but getting closer ..
 
Blackketter.. are you configured for 3 wire spi or 4 wire spi .. I'm configured for 4 wire spi
 
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I had tried spi clock from 40 MHz fown to 20 MHz then finally down to 6 MHz .. and the screen is the same ..I pulled it apart tonight , but the screen is very dim.. I'll put it back together and get a screen shot .
 
UPDATE ... of my two 1280 x 400 pixel screens .. The screen I was initially working with was actually defective .. The second screen worked ..
So pulled my hair out working with a bad screen for several weeks ..
Got the second one up and running .
Then swapped displays to test the first screen again
... FAILED!

So I have 1 working and 1 dud ..
I appreciate all the help from the members here to help move me forward ..
Thankyou for putting the time in
and giving me direction ...

cheers
Keith
 
Now if I could get the GT911 capacitive touch controller working I'd be on my way .. but not finding libraries !! ..any thoughts
 
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