Pengukuran Frekuensi DAC MCP4725 pada ESP32
Foto perangkat
Kode Pengujian
#include <Wire.h>
#include <Adafruit_MCP4725.h>
#include <Wire.h>
#define I2C_SDA 15
#define I2C_SCL 13
Adafruit_MCP4725 dac;
void setup(void) {
int address = 0;
int hasil;
uint32_t speed = 400000L;
int status;
status = Wire.begin(I2C_SDA, I2C_SCL, speed);
Serial.begin(115200);
Serial.print("Hello! Wire Init status:");
Serial.println(status);
Serial.println(speed);
address = 0x62;
dac.begin(address);
Serial.println("Search I2C");
SearchI2C();
Serial.println("benchmark");
}
int start_sawtooth = 0;
int current_time;
int duration;
int time_begin;
int time_now;
uint32_t counter;
void loop(void) {
dac.setVoltage(0, false);
dac.setVoltage(4095, false);
counter = counter + 1;
if (counter >= 10000) {
float period;
int time_now = millis();
counter = 0;
duration = time_now - time_begin;
period = duration / 10000.0 / 2;
Serial.print("period (ms): ");
Serial.println(period);
// prepare next round
time_begin = time_now;
}
}
void SearchI2C() {
byte error, address;
int nDevices;
Serial.println("Scanning...");
nDevices = 0;
for (address = 1; address < 127; address++) {
// Serial.println(address, HEX);
// The i2c_scanner uses the return value of
// the Write.endTransmisstion to see if
// a device did acknowledge to the address.
Wire.beginTransmission(address);
error = Wire.endTransmission();
if (error == 0) {
Serial.print("I2C device found at address 0x");
if (address < 16)
Serial.print("0");
Serial.print(address, HEX);
Serial.println(" !");
nDevices++;
} else if (error == 4) {
Serial.print("Unknown error at address 0x");
if (address < 16)
Serial.print("0");
Serial.println(address, HEX);
}
}
if (nDevices == 0)
Serial.println("No I2C devices found\n");
else
Serial.println("done\n");
}Pengukuran
Hasil pengukuran perioda
benchmark
period (ms): 0.18
period (ms): 0.17
period (ms): 0.17Hasil pengukuran sinyal output DAC
Frekuensi DAC adalah 2,867 kHz x 2 = 5,734 kHz
Kesimpulan
Perioda : 0.17 ms
Frekuensi: 5,734 kHz
Referensi