How to change cpu frequency

[PépéMax]

Hi, how change cpu frequency on the M5Stack.
I use platformio
Thanks

[Calin]

@pépémax 在 How to change cpu frequency 中说：

Hi, how change cpu frequency on the M5Stack.
I use platformio
Thanks

on platformio.ini use

board_build.f_cpu = 240000000L

to set the CPU speed to 240Mhz

[PépéMax]

@Calin
Thanks but it's not working

board_build.f_cpu = 200000000L

but when I use the function :

//before Setup()
int cpuSpeed = ESP.getCpuFreqMHz();
//In loop()
Serial.println(cpuSpeed);

In my serial monitor it display 240