What are the best settings in grbl 1.1e / cpu_map.h for a laserdriver with

What are the best settings in grbl 1.1e / cpu_map.h for a laserdriver with this specifications:
Model: SHS-2500
Current (mA): 2500
Supply Voltage (VDC): 3~24
Modulation (kHz Analog / kHz TTL): 500 / 250
Modulation Voltage (VDC): 0~5
Rise-Fall-Time (μs): 1.4
Noise (mV): 1.6

GRBL runs on an Arduino Uno R3.

cpu_map.h:
// Prescaled, 8-bit Fast PWM mode.
#define SPINDLE_TCCRA_INIT_MASK ((1<<WGM20) | (1<<WGM21)) // Configures fast PWM mode.
// #define SPINDLE_TCCRB_INIT_MASK (1<<CS20) // Disable prescaler → 62.5kHz
// #define SPINDLE_TCCRB_INIT_MASK (1<<CS21) // 1/8 prescaler → 7.8kHz (Used in v0.9)
// #define SPINDLE_TCCRB_INIT_MASK ((1<<CS21) | (1<<CS20)) // 1/32 prescaler → 1.96kHz
#define SPINDLE_TCCRB_INIT_MASK (1<<CS22) // 1/64 prescaler → 0.98kHz (J-tech laser)

Have you tried running with the default setting?

Yes, but then I got jagged cutting edges.

I think they write about my issue. It is a KHZ problem.

I was leaning towards an increased frequency, but, it was only a guess.

I was leaning towards an increased frequency, but, it was only a guess.

Max. kHz from an Arduino UNO is only 62.5. The driver needs “Modulation (kHz Analog / kHz TTL): 500 / 250”. Did anybody have an idea how to solve this issue?

After a test with 5V from a battery with the same result, now I changed my pulleys to 20 teeth (before 30) and the jagged cutting lines are history.

I’m glad to see you found a solution to your problem.