Difference between revisions of "Matrix - Pressure and Temperature Sensor"

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Thus, a difference in altitude of ∆altitude = 10m corresponds to 1.2hPa pressure change at sea level.
 
Thus, a difference in altitude of ∆altitude = 10m corresponds to 1.2hPa pressure change at sea level.
  
 +
==硬件连接==
 +
===连接NanoPi M1===
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Pressure_and_Temperature_Sensor_nanopi_m1.jpg|frameless|600px|Matrix-Pressure_and_Temperature_Sensor_nanopi_m1]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Pressure_and_Temperature_Sensor || NanoPi M1     
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || Pin6
 +
|}
 +
 +
===连接NanoPi 2===
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Pressure_and_Temperature_Sensor_nanopi_2.jpg|frameless|600px|Matrix-Pressure_and_Temperature_Sensor_nanopi_2]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Pressure_and_Temperature_Sensor || NanoPi 2
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || Pin6
 +
|}
 +
 +
===连接NanoPi M2 / NanoPi 2 Fire===
 +
NanoPi M2和NanoPi 2 Fire的40 Pin引脚定义是一模一样的，所以它们操作Matrix配件的步骤是一样的，这里仅以NanoPi M2为例。<br>
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Pressure_and_Temperature_Sensor_nanopi_M2.jpg|frameless|600px|Matrix-Pressure_and_Temperature_Sensor_nanopi_M2]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
| || NanoPi M2     
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || Pin6
 +
|}
 +
 +
===连接NanoPC-T2===
 +
参考下图连接模块：<br>
 +
[[File:Matrix-Pressure_and_Temperature_Sensor_NanoPC-T2.jpg|frameless|600px|Matrix-Pressure_and_Temperature_Sensor_NanoPC-T2]]
 +
 +
连接说明：
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Pressure_and_Temperature_Sensor || NanoPC-T2
 +
|-
 +
|SDA    || Pin6
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin29
 +
|-
 +
|GND    || Pin30
 +
|}
 +
 +
==编译运行测试程序==
 +
启动开发板并运行Debian系统，进入系统后克隆Matrix代码仓库：
 +
<syntaxhighlight lang="bash">
 +
$ apt-get update && apt-get install git
 +
$ git clone https://github.com/friendlyarm/matrix.git
 +
</syntaxhighlight>
 +
克隆完成后会得到一个名为matrix的目录。
 +
 +
编译并安装Matrix：
 +
<syntaxhighlight lang="bash">
 +
$ cd matrix
 +
$ make && make install
 +
</syntaxhighlight>
 +
 +
运行测试程序：
 +
<syntaxhighlight lang="bash">
 +
$ matrix-pressure_temp
 +
</syntaxhighlight>
 +
注意：此模块并不支持热插拔，启动系统前需要确保硬件连接正确。<br>
 +
运行效果如下：<br>
 +
<syntaxhighlight lang="bash">
 +
The temperature is 26.6 C
 +
The pressure is 983.91 hPa
 +
The altitude is 247.18
 +
</syntaxhighlight>
 +
 +
==代码说明==
 +
所有的开发板都共用一套Matrix代码，本模块的测试示例代码为matrix-pressure_and_temperature_sensor，内容如下:
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int ret = -1;
 +
    int bmpTemp=0, bmpPressure=0;
 +
    int board;
 +
    float altitude = 0;
 +
   
 +
    if ((board = boardInit()) < 0) {
 +
        printf("Fail to init board\n");
 +
        return -1;
 +
    }
 +
   
 +
    system("modprobe "DRIVER_MODULE);
 +
    if ((ret = bmp180Read(BMP180_TEMP, &bmpTemp)) != -1) {
 +
        printf("The temperature is %.1f C\n", (float)bmpTemp / 10);
 +
    } else {
 +
        printf("Faided to get humidity\n");
 +
    }
 +
    if ((ret = bmp180Read(BMP180_PRESSURE, &bmpPressure)) != -1) {
 +
        printf("The pressure is %.2f hPa\n", (float)bmpPressure / 100);
 +
    } else {
 +
        printf("Faided to get pressure\n");
 +
    }
 +
 +
    altitude = 44330 * ( 1 - pow( ((float)bmpPressure / 100 / 1013.25), (1/5.255) ) );
 +
    printf("The altitude is %.2f m\n", altitude);
 +
    system("rmmod "DRIVER_MODULE);
 +
    return 0;
 +
}
 +
</syntaxhighlight>
 +
API说明参考维基：[[Matrix API reference manual/zh|Matrix API reference manual]] <br>
 +
<!---
 
==Download Matrix Source Code==
 
==Download Matrix Source Code==
 
All the matrix modules' code samples are open source. They are maintained on GitHub - https://github.com/friendlyarm/matrix.git <br>
 
All the matrix modules' code samples are open source. They are maintained on GitHub - https://github.com/friendlyarm/matrix.git <br>
Line 244: Line 379:
  
 
==Connect to Arduino==
 
==Connect to Arduino==
 +
--->
  
 
==Resources==
 
==Resources==

Revision as of 14:31, 23 June 2016

查看中文

1 Introduction

Matrix-Pressure and Temperature Sensor.png
  • The BMP180 is a high precision, ultra-low power small digital pressure sensor for consumer applications in mobile phones, PDAs, GPS navigation devices and outdoor equipments. With a low altitude noise of merely 0.25m at fast conversion time, the BMP180 offers superior performance. The I2C interface allows for easy system integration with a microcontroller.
  • The BMP180 is based on piezo-resistive technology for EMC robustness, high accuracy and linearity as well as long term stability.
  • The BMP180 consists of a piezo-resistive sensor, an analog to digital converter and a control unit with E2PROM and a serial I2C interface. The E2PROM has stored 176 bit of individual calibration data. This is used to compensate offset, temperature dependence and other parameters of the sensor.

2 Features

  • I2C，3.3V
  • Pressure data(16 to 19 bit)
  • Temperature data(16 bit)
  • PCB Dimension(mm): 16 x 16

Matrix-Pressure and Temperature Sensor PCB.png

  • Pin Description:
Pin Description
SDA I2C SDA
SCL I2C SCL
5V Supply Voltage 5V
GND Ground

3 Basic Device Operation

  • The mode (ultra low power, standard, high, ultra high resolution) can be selected by the variable oversampling_setting (0, 1, 2, 3) in the C code.
  • Calculation of true temperature and pressure in steps of 1Pa (= 0.01hPa = 0.01mbar) and temperature in steps of 0.1°C.
  • With the measured pressure p and the pressure at sea level p0 e.g. 1013.25hPa, the altitude in meters can be calculated with the international barometric formula: Matrix-Pressure and Temperature Sensor Calculat.png
  • With the measured pressure p and the absolute altitude the pressure at sea level can be calculated:

Matrix-Pressure and Temperature Sensor Calculat01.png Thus, a difference in altitude of ∆altitude = 10m corresponds to 1.2hPa pressure change at sea level.

4 硬件连接

4.1 连接NanoPi M1

参考下图连接模块：
Matrix-Pressure_and_Temperature_Sensor_nanopi_m1

连接说明：

Matrix-Pressure_and_Temperature_Sensor NanoPi M1
SDA Pin3
SCL Pin5
5V Pin4
GND Pin6

4.2 连接NanoPi 2

参考下图连接模块：
Matrix-Pressure_and_Temperature_Sensor_nanopi_2

连接说明：

Matrix-Pressure_and_Temperature_Sensor NanoPi 2
SDA Pin3
SCL Pin5
5V Pin4
GND Pin6

4.3 连接NanoPi M2 / NanoPi 2 Fire

NanoPi M2和NanoPi 2 Fire的40 Pin引脚定义是一模一样的，所以它们操作Matrix配件的步骤是一样的，这里仅以NanoPi M2为例。
参考下图连接模块：
Matrix-Pressure_and_Temperature_Sensor_nanopi_M2

连接说明：

NanoPi M2
SDA Pin3
SCL Pin5
5V Pin4
GND Pin6

4.4 连接NanoPC-T2

参考下图连接模块：
Matrix-Pressure_and_Temperature_Sensor_NanoPC-T2

连接说明：

Matrix-Pressure_and_Temperature_Sensor NanoPC-T2
SDA Pin6
SCL Pin5
5V Pin29
GND Pin30

5 编译运行测试程序

启动开发板并运行Debian系统，进入系统后克隆Matrix代码仓库： 

$ apt-get update && apt-get install git
$ git clone https://github.com/friendlyarm/matrix.git

克隆完成后会得到一个名为matrix的目录。

编译并安装Matrix： 

$ cd matrix
$ make && make install

运行测试程序： 

$ matrix-pressure_temp

注意：此模块并不支持热插拔，启动系统前需要确保硬件连接正确。
运行效果如下：

The temperature is 26.6 C
The pressure is 983.91 hPa
The altitude is 247.18

6 代码说明

所有的开发板都共用一套Matrix代码，本模块的测试示例代码为matrix-pressure_and_temperature_sensor，内容如下: 

int main(int argc, char ** argv) 
{ 
    int ret = -1;
    int bmpTemp=0, bmpPressure=0;
    int board;
    float altitude = 0;
 
    if ((board = boardInit()) < 0) {
        printf("Fail to init board\n");
        return -1;
    }
 
    system("modprobe "DRIVER_MODULE);
    if ((ret = bmp180Read(BMP180_TEMP, &bmpTemp)) != -1) {
        printf("The temperature is %.1f C\n", (float)bmpTemp / 10);
    } else {
        printf("Faided to get humidity\n");
    }
    if ((ret = bmp180Read(BMP180_PRESSURE, &bmpPressure)) != -1) {
        printf("The pressure is %.2f hPa\n", (float)bmpPressure / 100);
    } else {
        printf("Faided to get pressure\n");
    }
 
    altitude = 44330 * ( 1 - pow( ((float)bmpPressure / 100 / 1013.25), (1/5.255) ) );
    printf("The altitude is %.2f m\n", altitude);
    system("rmmod "DRIVER_MODULE);
    return 0;
}

API说明参考维基：Matrix API reference manual

7 Resources

BMP180.pdf

8 Update Log

8.1 Feb-24-2016

  • Added the whole English version

8.2 Feb-26-2016

  • Translated into English
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