Display TFT ST7789 (OshonSoft Basic).

[DogFlu66]

I leave the library to use ST7789 TFT display, I have translated one that is in C language. But unfortunately I have not been able to get it to work yet. I leave the files in case someone with more experience with these displays can review it.

 

[Ian Rogers]

I just ran the dummy at 3.6v and nada... still searching

 

[camerart]

Hi,
I have some 18F4620 PICs, I can try on of these.
What do you think?
C

 

[Ian Rogers]

I have pic18f4620's It works okay

 

[camerart]

I have pic18f4620's It works okay

Hi I,
Ok, I'll try one.
C

 

[Ian Rogers]

Okay.. More news.... The pic18f46k20. is now working but at 3.8v and!! with your code AND!! at 8Mhz.

3.6v isn't enough.. The pic needs at least 3.8v to gey a good SPI clock at that speed. The LCD is messing the clock and data up as it needs that tiny bit extra.
https://youtube.com/shorts/Kmqh_jAUoOA?feature=share

 

[camerart]

Okay.. More news.... The pic18f46k20. is now working but at 3.8v and!! with your code AND!! at 8Mhz.

3.6v isn't enough.. The pic needs at least 3.8v to gey a good SPI clock at that speed. The LCD is messing the clock and data up as it needs that tiny bit extra.
https://youtube.com/shorts/Kmqh_jAUoOA?feature=share

Hi I,
Stop the press!! I was just about to swap the 46K20 to 4620 on my board.

I notice that you and, I think D are both using TTH PICs, where mine is surface mount, I wonder if there's a difference. Something to remember!
Have you tried the same CODE on my board?

I was going to change the voltage regulator on my board, but the 18F46K20 only goes to 3.6V. Where the 18F4620 goes to 5.5V

I've been searching for other clues and see lots of SPI pull up resistors and caps mentioned.

C.

 

[Ian Rogers]

No.. The max on the pic18f46k20 is 4.2V Max! So I can run it from a 18650 3.7v battery ( which is 4.2v really) and I paralleled two diodes to bring it down to 3.8v (ish)..

Pullups do nothing and caps will increase the already bad slew... The shortest wires ever and that increased voltage seems to work.