我正在用 C 语言(使用 ESP32 的工具链)对 ESP32 进行编程,我正在尝试更改我的 ESP32 的时钟频率,但我不确定我是否做对了(我使用了文档 https:/ /docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/power_management.html#_CPPv418esp_pm_lock_type_t 但我没有找到任何代码示例)。我认为我已经正确完成了程序部分,但我认为它仍然不起作用。有没有办法弄清楚设置的时钟频率? 我也不确定文档中的这一部分: “ESP_PM_CPU_FREQ_MAX 要求 CPU 频率为通过 esp_pm_configure 设置的最大值。参数未使用,应设置为 0。” 最后一部分是否意味着我不应该使用这个 makro?
最后但同样重要的是,我不明白我是否必须更改我的 sdkconfig 或者是否有办法在 C 中完成所有事情?
我必须测量 ns 区域的项目时间,因此我需要 esp32 的最大性能。
代码:
// ____________________________________________________________________________
esp_pm_config_esp32_t config_clock_struct;
// ____________________________________________________________________________
esp_pm_config_esp32_t* pointer_config_clock = &config_clock_struct;
// ____________________________________________________________________________
esp_pm_lock_handle_t handle;
void config_clock(int max_cpu_freq, int min_cpu_freq, bool light_sleep_enable,
esp_pm_config_esp32_t* pointer_config_clock) {
pointer_config_clock->max_freq_mhz = max_cpu_freq;
pointer_config_clock->min_freq_mhz = min_cpu_freq;
pointer_config_clock->light_sleep_enable = light_sleep_enable;
esp_err_t status = esp_pm_configure(pointer_config_clock);
if (status == ESP_OK) {
return;
} else if (status == ESP_ERR_INVALID_ARG) {
printf("Error %d: Configuration values aren't correct.", status);
exit(1);
} else if (status == ESP_ERR_NOT_SUPPORTED) {
printf("Error %d: Combination of values aren't supported or CONFIG_PM_ENABLE isn't enabled in sdkconfig.",
status);
exit(1);
}
}
// ____________________________________________________________________________
void init_clock(int max_cpu_freq, int min_cpu_freq, bool light_sleep_enable,
esp_pm_lock_type_t lock_type, int arg, const char* name,
esp_pm_config_esp32_t* pointer_config_clock, esp_pm_lock_handle_t* out_handle) {
config_clock(max_cpu_freq, min_cpu_freq, light_sleep_enable, pointer_config_clock);
esp_err_t status = esp_pm_lock_create(lock_type, arg, name, out_handle);
if (status == ESP_OK) {
return;
} else if (status == ESP_ERR_NO_MEM) {
printf("Error %d: Struct can't allocated.", status);
} else if (status == ESP_ERR_INVALID_ARG) {
printf("Error: %d: Invalid arguments.", status);
} else if(ESP_ERR_NOT_SUPPORTED == status) {
printf("Error %d: config pm is not enabled in sdkconfig.", status);
}
}
和主要功能的相关部分:
#define MAX_FREQUENCY 240
#define MIN_FREQUENCY 40
#define DISABLE_SLEEP 0
init_clock(MAX_FREQUENCY, MIN_FREQUENCY, DISABLE_SLEEP, ESP_PM_CPU_FREQ_MAX, ESP_PM_CPU_FREQ_MAX,
"measure mode", pointer_config_clock, &handle);
esp_err_t status_acquire = esp_pm_lock_acquire(handle);
当改变 MCU 时钟频率时,它会改变所有与频率相关的总线。例如 UART 和 I2C。这里有一个巧妙的技巧来演示时钟频率的变化如何影响
serial.print
输出。请注意,您计算出的串行波特率因每个时钟速度设置而异。
//function takes the following frequencies as valid values:
// 240, 160, 80 <<< For all XTAL types
// 40, 20, 10 <<< For 40MHz XTAL
// 26, 13 <<< For 26MHz XTAL
// 24, 12 <<< For 24MHz XTAL
// 32Bit MCUs . change for 16bit
uint32_t Freq = 0;
int MCU_FREQUENCY_SERIAL_SPEED=115200;
int SERIAL_DEFAULT_SPEED = 115200;
void changeMcuFreq(int Freq){
delay(500);
setCpuFrequencyMhz(Freq);
changeSerialBaudRate(Freq);
delay(500);
}
void serialMcuFreq(){
Freq = getCpuFrequencyMhz();
Serial.print("CPU Freq = ");
Serial.print(Freq);
Serial.println(" MHz");
Freq = getXtalFrequencyMhz();
Serial.print("XTAL Freq = ");
Serial.print(Freq);
Serial.println(" MHz");
Freq = getApbFrequency();
Serial.print("APB Freq = ");
Serial.print(Freq/1000000);
Serial.println(" MHz");
}
void changeSerialBaudRate(uint32_t Freq){
if (Freq < 80) {
MCU_FREQUENCY_SERIAL_SPEED = 80 / Freq * SERIAL_DEFAULT_SPEED;
}
else {
MCU_FREQUENCY_SERIAL_SPEED = SERIAL_DEFAULT_SPEED;
}
// Dont do the 4 lines below or it will crash the ESP32 device
// Serial.end();
// delay(1000);
// Serial.begin(MCU_FREQUENCY_SERIAL_SPEED);
//delay(1000);
Serial.print("\nSerial Baud Rate Speed is ");
Serial.println(MCU_FREQUENCY_SERIAL_SPEED);
}
void setup()
{
Serial.begin(MCU_FREQUENCY_SERIAL_SPEED);
}
void loop()
{
changeMcuFreq(240);
serialMcuFreq();
delay(2000);
changeMcuFreq(160);
serialMcuFreq();
delay(2000);
changeMcuFreq(80);
serialMcuFreq();
delay(2000);
changeMcuFreq(40);
serialMcuFreq();
delay(2000);
changeMcuFreq(20);
serialMcuFreq();
delay(2000);
changeMcuFreq(10);
serialMcuFreq();
delay(2000);
}
要查看此代码在 .ino 草图上的工作,请查看此 GitHub 存储库 https://github.com/aeonSolutions/aeonlabs-ESP32-C-Base-Firmware-Libraries