Hi,
What ever i do, this QVGA 2.2" tft screen is coming with blank screen.
(https://nl.aliexpress.com/item/33012793224.html?spm=a2g0s.9042311.0.0.3e184c4dK0Lplv)
I have installed the necessary libraries like :
#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"
I am testing with the graphicstest.ino of Adafruit_ILI9341-master.
Compiling and upload is no problem. But the screen stays blank.
I checked double all connections and even the power. I connected the vcc and led to 3.3volt.
I have the latest Arduino UNO.
Further:
- i am working on a mac
- Board : Arduino / Geniono UNO
- programmer : ArduinoISP.org
Why i do get this blank screen?
All of those Red boards require 3.3V logic signals.
It is no good relying the onboard 3.3V regulator and thinking that this makes the signals 5V tolerant.
Provide some form of level shifting e.g.
- 10k series resistors
- potential dividers e.g. 4k7+10k
- i.c.s on breakout board e.g. from Ebay
There are lots of different i.c. chips that can provide the level shifting
It is a mystery why anyone makes or sells 5V Arduino boards. Life is much simpler with Zero, Due, STM32, ESP32, ...
Nice Chinese shops sell Uno clones with switchable 3.3V / 5V logic e.g. like this
Yes, I know that it is annoying when shops say "Arduino" when you have to add extra electronics.
There are "Uno shields" that have the necessary level shifters on the pcb e.g. from Adafruit, Seeed, Waveshare, ...
They cost more but at least you can plug-and-go.
David.
David hi,
Thanks a lot. Really.
So you think it is an voltage issue and when i would connect the display with a real 3.3v then i should be working?
I added an external 3.3 volt. But still white screen. Even after re compiling and uploading.
I even tested with lower and higher voltage to 5 volts.
A Uno has 5V logic signals.
Plug your screen into one side of a mini-breadboard. Plug the Uno into the other side.
Place 10k resistors to link each signal. e.g. CS, DC, RST, MOSI, SCK, LED, (MISO)
Place straight wires to link power e.g. GND, VCC,
There are lots of tutorials and diagrams for these Red boards.
Do you have any 10k resistors?
Do you have any i.c.s ?
David.
David hi,
I have an arduino uno that has 3.3v and 5v delivering.
So i thought that should be enough. Because i read that older uno boards dont had 3.3v. And with the newer arduino boards the 3.3v should be enough.
So, even i have connected the display with an powersupply that delivers 3.3v you say do it with 10k resistors?
No, i dont have them. I will order them.
i.c.s. ?
