[活动] 【测评SGP40】+用arduino测试传感器 I2C通信

【测评SGP40】+用arduino测试传感器 I2C通信

本来用arduino测试SVM40 I2C通讯是一个容易的事。但折腾了一下。花了些时间。

1，下载arduino-snippets-main包 解压。

2，使用里面的\arduino-snippets-main\arduino-snippets-main\SVM40_I2C_minimal_example例子。

3，准备接好电路，传感器板 VCC GND接stm32F767板子 VCC  地， 3腿 SDA 接 PB8，  4腿SCL PB9，5腿 接地

4，PB8，PB9接4.7K上拉电阻。记得 否则是数据不变哦

5，打开\arduino-snippets-main\arduino-snippets-main\SVM40_I2C_minimal_example

6,用arduino1.8.13 打开SVM40_I2C_minimal_example.ino 

注意这里已经是安装好stm32duino包了得。具体可以看我的帖子 让arduino 把你的无用的stm32板子玩起来 之一

7，修改I2C时钟为100K。具体如下

#include <Wire.h>
// SVM40
const int16_t SVM40_ADDRESS = 0x6A;
void setup() {
  Serial.begin(115200);
  // wait for serial connection from PC
  // comment the following line if you'd like the output
  // without waiting for the interface being ready
  while(!Serial);
  // output format
  Serial.println("VOC_Index\tRH\tT");
  // init I2C
  Wire.setClock(100000L);//修改I2C时钟 据说模块最多100K
  Wire.begin();
  // wait until sensors startup, > 1 ms according to datasheet
  delay(1);
  // start up sensor, sensor will go to continous measurement mode
  // each second there will be new measurement values
  Wire.beginTransmission(SVM40_ADDRESS);
  Wire.write(0x00);
  Wire.write(0x10);
  Wire.endTransmission();
  // wait until sensors is ready, fan is initialized
  delay(1000);
}
void loop() {
  uint16_t voc, humidity, temperature;
  uint8_t data[9], counter;
  // read measurement data
  Wire.beginTransmission(SVM40_ADDRESS);
  Wire.write(0x03);
  Wire.write(0xA6);
  Wire.endTransmission();
  // wait 5 ms to allow the sensor to fill the internal buffer
  delay(5);
  // read measurement data svm40, after two bytes a CRC follows
  Wire.requestFrom(SVM40_ADDRESS, 9);
  counter = 0;
  while (Wire.available()) {
    data[counter++] = Wire.read();
  }
  // VOC level is a signed int and scaled by a factor of 10 and needs to be divided by 10
  // humidity is a signed int and scaled by 100 and need to be divided by 100
  // temperature is a signed int and scaled by 200 and need to be divided by 200
  voc = (uint16_t)data[0] << 8 | data[1];
  humidity = (uint16_t)data[3] << 8 | data[4];
  temperature = (uint16_t)data[6] << 8 | data[7];
  Serial.print(String(float(voc) / 10));
  Serial.print("\t");
  Serial.print(String(float(humidity) / 100));
  Serial.print("\t");
  Serial.print(String(float(temperature) / 200));
  Serial.println();
  delay(1000);
}

8，编译下载。 运行。

结果出来了，今晚24.8度 

 还可以这样玩，用stm32duino安装包

谢谢分享

是啊挺方便的。手上的板子可以玩起来。

这个空中飞电阻的操作哈哈，有那么点意思，以前也用过这样的方式！