I'm pretty disappointed with the brightness of my Giga Display shield. Even when I max out the brightness to 100%, the display remains painfully dim—nowhere near the brightness of my other 3.5" displays or even a typical cellphone.
Is there is some mechanical, electrical, or software tweak that can significantly boost the brightness?
Do you have the latest library? If you have a multimeter, does 3.3 V reads that or very close? (Not likely that is the issue, but for a start in the troubleshooting) Is the picture visible in a dark room?
Arduino_GigaDisplay is rev1.02.
Arduino_GigaDisplay_GFX is rev 1.00
It is not so dark that I need to be in a dark room to see it. It is light enough to see it in the house during the day, but it is not bright. I know it's a subjective thing and I don't have any way to actually measure the brightness. All I can say about it is I was expecting it to be a lot brighter and it is not nearly as bright as my other displays or iPhone.
The LED backlight should be able to provide lots of light and it should be quite visible in the house at far less than100%.
Tomorrow, I'll take it out of the case I made for it and measure the voltage.
It's probably that, something wrong with a resistor or the like.
This is what I found when seeking answers on the lack of good brightness of my Giga Display Shield.
As you can see in the schematic the backlight is controlled by a LV52204MTTBG LED boost driver and the amount of current to the backlight is controlled by R28 and R29 which totals 5 ohms. Those tiny resistors would have to change to increase the current. That is out of the question for me because they are too small, and I would not know what values to use anyway.
I decided to try to see what I could do with the brightness from a sw point of view. The code below adjusts the brightness from 0 to 100 and back repeatedly with 100ms between steps. On screen, the brightness changes in chunks, not smoothly. It looks like there are 10 levels of brightness and the top 3 or 4 level do not result in a perceptible change in brightness. The bottom 6 levels are readily discernable.
What I conclude from this is I can only see 60%-70% of the brightness which explains why it seems to be less bright than it should.
NOTE: I am not an engineer, so this is just what it looks like to me.
#include <Arduino_GigaDisplay.h> // Include the GigaDisplay library for display control
#include <Arduino_GigaDisplay_GFX.h> // Include the GFX library for drawing on the display
GigaDisplay_GFX d; // Create a GigaDisplay_GFX object
// Create backlight object
GigaDisplayBacklight backlight;
int intensity = 0; // Current backlight intensity (0-100)
int step = 1; // Step value: +1 when increasing, -1 when decreasing
void setup() {
backlight.begin(); // Initialize the backlight
d.fillScreen(0xFFFF); // Fill the display screen with white
}
void loop() {
backlight.set(intensity); // Set the backlight intensity
intensity += step; // Update intensity by one step
// Reverse direction when reaching the bounds
if (intensity >= 100) {
intensity = 100; // Ensure intensity doesn't exceed 100
step = -1; // Start decreasing intensity
} else if (intensity <= 0) {
intensity = 0; // Ensure intensity doesn't drop below 0
step = 1; // Start increasing intensity
}
delay(100); // Delay to control the update rate
}
Thanks for sharing that schematic.
As a point of reference I have three GIGA Displays and two are decently bright and the third is usable but I consider it dim. They all run from a USB power source and run the same software. And it's consistent no matter what software I run.
Peel off the protective sheet. It makes a big difference in sharpness and brightness too.
Do you have any way to measure the voltage across those two resistors?
I haven't yet tried to figure out why my one display is dim...
I'll try to measure it tomorrow, but being just 5 ohms, I doubt it's going to be much voltage..
I'm getting .041 V at the brightest setting.
What are you getting on your 3 displays?