Panel not fully utilizing full brightness?

Hi there,

I got my first RGB LED Matrix (https://aliexpress.com/item/32757647402.html) paired with the Adafruit (Adafruit RGB Matrix Bonnet for Raspberry Pi : ID 3211 : $14.95 : Adafruit Industries, Unique & fun DIY electronics and kits) up and running and so far it’s been a blast creating various programs for it. I also have a 5V 15A power supply plugged into the Bonnet.

But the panel is surprisingly dim. Based on my testing, the LEDs can sustain being very bright for quite long.
Currently I am achieving 110Hz when driving the full panel with just about any python program, even when there are some relatively heavy calculations in each loop.
The options I am using are below. If I for example use rows=8 and cols=16 I can achieve 960Hz, each individual pixel gets a lot brighter (in this case specifically presumably because each pixel gets adressed multiple times?).
The python program looks roughly like this:

import numpy as np
import rgbmatrix
options = rgbmatrix.RGBMatrixOptions()
options.rows = 64
options.cols = 64
options.show_refresh_rate = 1
options.pwm_lsb_nanoseconds = 80
options.led_rgb_sequence = "RBG"
options.hardware_mapping = "adafruit-hat"
arr = np.zeros((64,64,3), np.uint8)
while True:
    arr.fill(0)
    arr[:16,:16] = np.array([255,110,0])
    canvas.SetImage(Image.fromarray(arr).convert('RGB'))
    matrix.SwapOnVSync(canvas)

I am not specifically looking for a way to get a higher refresh rate, as 110Hz is easily enough for anything I have in mind. Is there instead anything I can do to get the full brightness out of my panel?

Any help is appreciated, thanks.

mmmh, I don’t use python, but you should get much higher refresh rate and brightness for 64x64,
Please compile all the C code and use rpi-rgb-led-matrix/examples-api-use/demo for testing.

When starting for example Demo 0 using the parameters listed below on my Pi 3 I get roughly 140Hz. I can not spot a noticable difference in brightness at that point.
Is it correct then, that brightness is directly linked to the refresh rate (apart from the selected color and the brigthness flag obviusly)? Or are there ways to achieve a higher brightness independent of just tweaking variuous parameters or running C code instead of python to achieve a higher refresh rate? The LEDs on the panel can clearly be very bright.

The command I am using to launch the C code:
sudo examples-api-use/demo -D 0 --led-cols=64 --led-rows=64 --led-gpio-mapping=adafruit-hat --led-rgb-sequence=RBG --led-show-refresh --led-pwm-lsb-nanoseconds=80

Yes, you can play with flags in GitHub - hzeller/rpi-rgb-led-matrix: Controlling up to three chains of 64x64, 32x32, 16x32 or similar RGB LED displays using Raspberry Pi GPIO
lower lsb-nanoseconds will be brighter
–led-pwm-bits set to lower values (like 7) should also be brighter
–led-pwm-dither-bits is brighter at 0 and faster at 2