sensors_event_t a, g, temp; mpu.getEvent(&a, &g, &temp);

&a, &g, &temp);

This code snippet retrieves sensor data from an MPU (Motion Processing Unit) using the getEvent() function. The retrieved data is stored in three separate sensor_event_t variables: a for acceleration data, g for gyroscope data, and temp for temperature data. The ampersand (&) symbol is used to pass the memory address of each variable to the function so that it can store the data directly in the variable.

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sensors_event_t a, g, temp; mpu.getEvent(&a, &g, &temp);这两段代码怎么用

&a, &g, &temp);

This code is using the MPU (Motion Processing Unit) library to read data from an MPU sensor. The MPU sensor has multiple sensors within it, including an accelerometer, a gyroscope, and a temperature sensor.

The code is declaring three variables of type sensors_event_t - a, g, and temp. These variables will be used to store the data from the accelerometer, gyroscope, and temperature sensor respectively.

The function mpu.getEvent() is being called to read the data from the sensor. This function takes three arguments - the accelerometer data, the gyroscope data, and the temperature data - and stores the data in the corresponding variables (a, g, and temp).

Overall, this code is reading data from an MPU sensor and storing it in variables for further processing.

改进代码 #include <SoftwareSerial.h> #include <Adafruit_Sensor.h> #include <DHT.h> #include <DHT_U.h> #include <Nextion.h> #define DHTPIN 2 #define DHTTYPE DHT11 DHT_Unified dht(DHTPIN, DHTTYPE); SoftwareSerial mySerial(10, 11); // RX, TX NexText g0 = NexText(0, 2, "g0"); // Specify the page ID and component ID for the temperature display NexText g1 = NexText(0, 3, "g1"); // Specify the page ID and component ID for the humidity display void setup() { Serial.begin(9600); while (!Serial); mySerial.begin(9600); dht.begin(); NexInit(); // Initialize the Nextion display } void loop() { sensors_event_t event; dht.temperature().getEvent(&event); float temperature = event.temperature; dht.humidity().getEvent(&event); float humidity = event.relative_humidity; // Send temperature and humidity data through serial communication mySerial.write((byte)(temperature / 256)); mySerial.write((byte)(temperature)); mySerial.write((byte)(humidity / 256)); mySerial.write((byte)(humidity)); // Display the temperature and humidity on the Nextion display String tempStr = String(temperature, 1) + "C"; String humStr = String(humidity, 1) + "%"; g0.setText(tempStr.c_str()); g1.setText(humStr.c_str()); delay(2000); }

在代码中，可以进行如下改进：

1. 在初始化串口时，可以加上一个延时，以确保串口正常启动。例如：

Serial.begin(9600);
while (!Serial) {
  delay(10);
}

2. 在发送数据到串口时，可以使用更好的数据类型。例如，使用 `float` 类型的变量 `temp` 和 `hum` 来存储温度和湿度数据，然后将它们转换为 `int` 类型的变量再发送到串口。例如：

float temp, hum;
dht.temperature().getEvent(&event);
temp = event.temperature;
dht.humidity().getEvent(&event);
hum = event.relative_humidity;

int tempInt = (int)(temp * 10);
int humInt = (int)(hum * 10);

mySerial.write((byte)(tempInt >> 8));
mySerial.write((byte)(tempInt & 0xFF));
mySerial.write((byte)(humInt >> 8));
mySerial.write((byte)(humInt & 0xFF));

3. 在设置文本显示时，可以使用 `dtostrf()` 函数将浮点数转换为字符串，并且可以使用更简洁的方式设置文本。例如：

char tempStr[10], humStr[10];
dtostrf(temp, 5, 1, tempStr);
dtostrf(hum, 5, 1, humStr);

g0.setText(tempStr);
g1.setText(humStr);