MAX7221 LED current low

Hello everybody,
I have an issue with my LED matrix driver current. Maybe one of you knows more an can help me out.
I use the LedControl library, I set the brightness to maximum (15) and I tested values for RSet between 10k and 28k.
The highest LED current I measured was 2.5mA, whereas my LEDs can take at least 20mA. How do I get a higher LED current, without adding a transistor to every LED?

Best regards

You really need to explain what it was you measured.

Exactly what circuit are you using? Is it a MAX2819?

The highest LED current I measured was 2.5mA,

You can not measure this current with a meter because it is pulsed, you will not get a meaningful reading.

If you want more current then make the value of RSet lower, read the data sheet for the limits. The LEDs are not as bright because they are being multiplexed at a low duty cycle.

Well, I really gained some insight. Grumpy_Mike, you pointed it out. I understand now. I already lowered RSet to 10K. It seems I have to live with that. Of course I did measure the LED current with a normal meter, and of course that isn't the peak current.

Thank you very much!!