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

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[[Matrix - Temperature and Humidity Sensor/zh|查看中文]]
 
[[Matrix - Temperature and Humidity Sensor/zh|查看中文]]
  
−
==介绍==
+
==Introduction==
 
[[File:TemperatureAndHumiditySensor01.png|thumb|Temperature and Humidity Sensor]]
 
[[File:TemperatureAndHumiditySensor01.png|thumb|Temperature and Humidity Sensor]]
−
* 模块Matrix-Temperature_and_Humidity_Sensor用于检测温度和湿度。
+
* The Matrix-Temperature_and_Humidity_Sensor module is used to detect temperature and humidity.
−
* 搭载了一颗DHT11温湿度传感器，湿度采集范围为20%-80%，误差为5%，温度采集范围为0℃-50℃，误差为±2℃。
+
* It utilizes the DHT11 temperature and humidity sensor. Its humidity range is 20% - 80% and the accuracy is 5%. Its temperature range is 0℃ - 50℃ and the accuracy is ±2℃.
  
−
==特性==
+
==Features==
−
* 测量范围 湿度20-80%RH， 温度0~50℃
+
* Humidity range: 20 - 80%RH, Temperature range 0 ~ 50℃
−
* 测量精度 湿度+-5%RH， 温度+-2℃
+
* Accuracy of humidity: +-5%RH, accuracy of temperature: +-2℃
−
* 一线协议
+
* One wire communication
−
* 2.54mm排针接口，接线方便，通用性强
+
* 2.54 mm spacing pin
−
* PCB尺寸（mm）：16x32
+
* PCB dimension (mm): 16 x 32
 
[[File:dht11pcb.png|frameless|400px|温湿度传感器PCB]]
 
[[File:dht11pcb.png|frameless|400px|温湿度传感器PCB]]
  
−
引脚说明: <br>
+
Pin Description: <br>
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
−
|名称 || 描述
+
|Pin || Description
 
|-
 
|-
 
|S    || GPIO
 
|S    || GPIO
 
|-
 
|-
−
|V    || 电源5V
+
|V    || Supply Voltage 5V
 
|-
 
|-
−
|G    || 地
+
|G    || Ground
 
|}
 
|}
  
−
==工作原理==
+
==Basic Device Operation==
−
DHT11模块使用串行接口方式传输数据，DATA 用于微处理器与 DHT11之间的通讯和同步,采用单总线数据格式,一次通讯时间4ms左右,数据分小数部分和整数部分,具体格式在下面说明,当前小数部分用于以后扩展,现读出为零.操作流程如下:  
+
The DHT11 module uses a simplified single-bus serial communication. DATA controls communication and synchronization between the microprocessor and DHT11. A data transfer takes 4ms. The data format contains an integer part and a decimal part. The basic operation is as follows:
−
* 一次完整的数据传输为40bit,高位先出。
+
* a transmission of 40 data, the high first-out
−
* 数据格式:8bit湿度整数数据+8bit湿度小数数据 <br>
+
* data format: 8bit humidity integer data + 8bit the Humidity decimal data <br>  
−
* +8bi温度整数数据+8bit温度小数数据 <br>
+
* 8bit temperature integer data + 8bit fractional temperature data <br>  
−
* +8bit校验和<br>  
+
* 8 bit parity bit <br>
−
* 数据传送正确时校验和数据等于“8bit湿度整数数据+8bit湿度小数数据+8bi温度整数数据+8bit温度小数数据”所得结果的末8位。<br>  
+
* If a transmission is successful the “8bit humidity integer data + 8bit humidity decimal data +8 bit temperature integer data + 8bit temperature fractional data” 8bit checksum is equal to the results of the last eight. <br>
−
* 用户MCU发送一次开始信号后,DHT11从低功耗模式转换到高速模式,等待主机开始信号结束后,DHT11发送响应信号,送出40bit的数据,并触发一次信号采集,用户可选择读取部分数据.从模式下,DHT11接收到开始信号触发一次温湿度采集,如果没有接收到主机发送开始信号,DHT11不会主动进行温湿度采集.采集数据后转换到低速模式。
+
* After the user host (MCU) sends a signal DHT11 is converted from low-power mode to high-speed mode, until the host begins to signal the end. Then DHT11 sends a response signal to send 40bit data, and trigger a letter collection. If DHT11 doesn't receive a signal from the host it will not begin a letter collection. After the letter collection is done DHT11 will turn to low power mode.
  
−
==下载Matrix源码==
 
−
Matrix配件相关的代码是完全开源的，统一由一个仓库进行管理：git://github.com/friendlyarm/matrix.git <br>
 
−
该仓库里不同的分支代表着Matrix配件所支持的不同开发板。<br>
 
−
* nanopi分支包含了Matrix对NanoPi的支持；
 
−
* tiny4412分支包含了Matrix对Tiny4412的支持；
 
−
* raspberrypi分支包含了Matrix对RaspberryPi的支持；
 
  
−
在主机PC上安装git，以Ubuntu14.04为例
+
==Applications==
 +
===Connect to NanoPi M1===
 +
Refer to the following connection diagram to connect the module to the NanoPi M1:<br>
 +
[[File:Matrix-Temperature_and_Humidity_Sensor_nanopi_m1.jpg|frameless|600px|Matrix-Temperature_and_Humidity_Sensor_nanopi_m1]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Temperature_and_Humidity_Sensor || NanoPi M1
 +
|-
 +
|S    || Pin7
 +
|-
 +
|V    || Pin4
 +
|-
 +
|G    || Pin6
 +
|}
 +
 
 +
===Connect to NanoPi 2===
 +
Refer to the following connection diagram to connect the module to the NanoPi 2:<br>
 +
[[File:Matrix-Temperature_and_Humidity_Sensor_nanopi_2.jpg|frameless|600px|Matrix-Temperature_and_Humidity_Sensor_nanopi_2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Temperature_and_Humidity_Sensor || NanoPi 2
 +
|-
 +
|S    || Pin7
 +
|-
 +
|V    || Pin4
 +
|-
 +
|G    || Pin6
 +
|}
 +
 
 +
===Connect to NanoPi M2 / NanoPi 2 Fire===
 +
Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire:<br>
 +
[[File:Matrix-Temperature_and_Humidity_Sensor_nanopi_m2.jpg|frameless|600px|Matrix-Temperature_and_Humidity_Sensor_nanopi_m2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Temperature_and_Humidity_Sensor || NanoPi M2
 +
|-
 +
|S    || Pin7
 +
|-
 +
|V    || Pin4
 +
|-
 +
|G    || Pin6
 +
|}
 +
 
 +
===Connect to NanoPC-T2===
 +
Refer to the following connection diagram to connect the module to the NanoPC-T2:<br>
 +
[[File:Matrix-Temperature_and_Humidity_Sensor_NanoPC-T2.jpg|frameless|600px|Matrix-Temperature_and_Humidity_Sensor_NanoPC-T2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Temperature_and_Humidity_Sensor || NanoPC-T2
 +
|-
 +
|S    || Pin15
 +
|-
 +
|V    || Pin29
 +
|-
 +
|G    || Pin30
 +
|}
 +
 
 +
==Compile & Run Test Program==
 +
Boot your ARM board with Debian and copy the matrix code:
 +
<syntaxhighlight lang="bash">
 +
$ apt-get update && apt-get install git
 +
$ git clone https://github.com/friendlyarm/matrix.git
 +
</syntaxhighlight>
 +
If your cloning is done successfully a "matrix" directory will be generated.
 +
 
 +
Compile and install Matrix:
 +
<syntaxhighlight lang="bash">
 +
$ cd matrix
 +
$ make && make install
 +
</syntaxhighlight>
 +
 
 +
Run test program:
 +
<syntaxhighlight lang="bash">
 +
$ matrix-temp_humidity
 +
</syntaxhighlight>
 +
Note: this module is not plug and play therefore before running the module please make sure it is connected to an ARM board.<br>
 +
Here is what you should observe:<br>
 +
<syntaxhighlight lang="bash">
 +
The humidity is 35000
 +
The temperature is 26000
 +
</syntaxhighlight>
 +
The module successfully read the environment's humidity and temperature values.
 +
 
 +
==Code Sample==
 +
This Matrix code sample can work with all the ARM boards mentioned in this module's wiki. The name of this code sample is "matrix-temperature_and_humidity_sensor". Here is its source code:
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int ret = -1;
 +
    int dhtTemp=0, dhtHdty=0, board;
 +
    char modStr[BUF_SIZE];
 +
    int pin = GPIO_PIN(7);
 +
 
 +
    if ((board = boardInit()) < 0) {
 +
        printf("Fail to init board\n");
 +
        return -1;
 +
    }   
 +
    if (board == BOARD_NANOPI_T2)
 +
        pin = GPIO_PIN(15);
 +
   
 +
    sprintf(modStr, "modprobe %s gpio=%d", DRIVER_MODULE, pintoGPIO(pin));
 +
    system(modStr);
 +
    if ((ret = dht11Read(DHT_HUMIDITY, &dhtHdty)) != -1) {
 +
        printf("The humidity is %d\n", dhtHdty);
 +
    } else {
 +
        printf("Faided to get humidity\n");
 +
    }
 +
    if ((ret = dht11Read(DHT_TEMP, &dhtTemp)) != -1) {
 +
        printf("The temperature is %d\n", dhtTemp);
 +
    } else {
 +
        printf("Faided to get temperature\n");
 +
    }
 +
    system("rmmod "DRIVER_MODULE);
 +
    return ret;
 +
}
 +
</syntaxhighlight>
 +
For more details about this APIs called in this code sample refer to [[Matrix API reference manual]] <br>
 +
 
 +
<!---
 +
==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>
 +
Each branch in this hub contains the matrix modules' code samples for a board that the matrix modules can work with.<br>
 +
* The nanopi branch contains the matrix modules' code samples for the NanoPi
 +
* The nanopi 2 branch contains the matrix modules' code samples for the NanoPi 2
 +
* The tiny4412 branch contains the matrix modules' code samples for the Tiny4412
 +
* The raspberrypi branch contains the matrix modules' code samples for the RaspberryPi
 +
 
 +
Please follow the steps below to get the source code:<br>
 +
Install the git utility on a PC running Ubuntu14.04
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ sudo apt-get install git
 
$ sudo apt-get install git
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
克隆Matrix配件代码仓库
+
Clone the matrix code from GitHub
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ git clone git://github.com/friendlyarm/matrix.git
+
$ git clone https://github.com/friendlyarm/matrix.git
 +
</syntaxhighlight>
 +
If this is successful a "matrix" directory will be generated, which will contain all the matrix modules' code samples.
 +
 
 +
==Connect to NanoPi 2==
 +
===Hardware Connection===
 +
Please refer to the following connection diagram to connect the Matrix-Temperature_and_Humidity_Sensor to the NanoPi 2:<br>
 +
[[File:Matrix-Temperature_and_Humidity_Sensor_nanopi_2.jpg|frameless|600px|Matrix-Temperature_and_Humidity_Sensor_nanopi_2]]
 +
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Temperature_and_Humidity_Sensor || NanoPi 2
 +
|-
 +
|S  || Pin7
 +
|-
 +
|V  || Pin4
 +
|-
 +
|G  || Pin6
 +
|}
 +
 
 +
===Compile Test Program===
 +
Please login the matrix hub and enter the nanopi2 branch
 +
<syntaxhighlight lang="bash">
 +
$ cd matrix
 +
$ git checkout nanopi2
 +
</syntaxhighlight>
 +
 
 +
Compile the matrix code
 +
<syntaxhighlight lang="bash">
 +
$ make CROSS_COMPILE=arm-linux- clean
 +
$ make CROSS_COMPILE=arm-linux-
 +
$ make CROSS_COMPILE=arm-linux- install
 +
</syntaxhighlight>
 +
Note: please make sure to install the cross compiler "arm-linux-gcc-4.9.3" on your PC, which is used to compile files for the NanoPi 2.<br>
 +
Generated library files are under the "install/lib" directory. The test program is under the "install/usr/bin" directory.<br>
 +
The modules are under the "modules" directory. The driver's source code is in github: https://github.com/friendlyarm/linux-3.4.y.git <br>
 +
 
 +
===Run Test Program===
 +
Please insert a TF card which is flashed with Debian to a Linux host and mount its boot and rootfs sections.<br>
 +
We assume the rootfs is mounted to /media/rootfs then please run the following commands to copy the module, library and test program to the card.<br>
 +
<syntaxhighlight lang="bash">
 +
$ cp modules /media/rootfs/ -r
 +
$ cp install/lib/* /media/rootfs/lib/ -d
 +
$ cp install/usr/bin/* /media/rootfs/usr/bin/
 +
</syntaxhighlight>
 +
 
 +
Insert this TF card to your NanoPi 2, power on and run the following commands to load the driver.<br>
 +
<syntaxhighlight lang="bash">
 +
$ cd /modules
 +
$ insmod dht11.ko
 +
</syntaxhighlight>
 +
 
 +
Start the matrix-temp_humidity program.<br>
 +
<syntaxhighlight lang="bash">
 +
$ matrix-temp_humidity
 +
</syntaxhighlight>
 +
 
 +
Here is what you expect to observe:<br>
 +
[[File:matrix-temp_humidity_result.png|frameless|600px|matrix-temp_humidity_result]] <br>
 +
 
 +
===Code Sample===
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int ret = -1;
 +
    int dhtTemp = 0;
 +
    int dhtHdty = 0;
 +
 
 +
    if ((ret = dht11Read(DHT_HUMIDITY, &dhtHdty)) != -1) {
 +
        printf("Get humidity : %d\n", dhtHdty);
 +
    } else {
 +
        printf("Faided to get humidity\n");
 +
    }
 +
 
 +
    if ((ret = dht11Read(DHT_TEMP, &dhtTemp)) != -1) {
 +
        printf("Get temperature : %d\n", dhtTemp);
 +
    } else {
 +
        printf("Faided to get temperature\n");
 +
    }
 +
 
 +
    return ret;
 +
}
 
</syntaxhighlight>
 
</syntaxhighlight>
−
克隆完成后会得到一个matrix目录，里面存放着所有Matrix配件的代码。
 
  
−
==与NanoPi连接使用==
+
==Connect to NanoPi==
−
===准备工作===
+
===Preparations===
−
在NanoPi上运行Debian系统，然后在主机PC上安装并使用相应的编译器。参考wiki：[[NanoPi/zh|NanoPi]] <br>
+
Please install a Debian on a NanoPi and an appropriate cross compiler on a PC. Please refer to wiki:[[NanoPi/zh|NanoPi]] <br>
−
注意：必须使用nanopi-v4.1.y-matrix分支编译出来的内核。<br>
+
Compile a NanoPi kernel. Note: please use the kernel's source code from the nanopi-v4.1.y-matrix branch.<br>
−
下载NanoPi内核源代码并编译
+
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ git clone https://github.com/friendlyarm/linux-4.x.y.git
 
$ git clone https://github.com/friendlyarm/linux-4.x.y.git
Line 67: Line 277:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-Temperature_and_Humidity_Sensor和NanoPi <br>
+
Please refer to the following connection diagram to connect the Matrix-Temperature_and_Humidity_Sensor to the NanoPi <br>
 
[[File:matrix-temperature_and_humidity_sensor_nanopi.jpg|frameless|600px|matrix-temperature_and_humidity_sensor_nanopi]]
 
[[File:matrix-temperature_and_humidity_sensor_nanopi.jpg|frameless|600px|matrix-temperature_and_humidity_sensor_nanopi]]
 
<br>
 
<br>
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 83: Line 293:
 
|}
 
|}
  
−
===编译测试程序===
+
===Compile Test Program===
−
进入Matrix代码仓库，切换到nanopi分支
+
Please login the matrix hub and enter the nanopi branch
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cd matrix
 
$ cd matrix
Line 90: Line 300:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
编译Matrix配件代码
+
Compile the matrix code
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ make CROSS_COMPILE=arm-linux- clean
 
$ make CROSS_COMPILE=arm-linux- clean
Line 96: Line 306:
 
$ make CROSS_COMPILE=arm-linux- install
 
$ make CROSS_COMPILE=arm-linux- install
 
</syntaxhighlight>
 
</syntaxhighlight>
−
注意：请确保你的主机PC当前使用的交叉编译器为NanoPi-Debian配套的arm-linux-gcc-4.4.3。<br>
+
Note: please make sure to install the cross compiler "arm-linux-gcc-4.4.3" on your PC, which is used to compile files for the NanoPi-Debian.<br>
−
编译出来的库文件位于install/lib目录下，而测试程序则位于install/usr/usr/bin目录下，模块Matrix-Temperature_and_Humidity_Sensor对应的测试程序为matrix-temp_humidity。<br>
+
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Temperature_and_Humidity_Sensor" module is "matrix-temp_humidity".<br>
  
−
===运行测试程序===
+
===Run Test Program===
−
拷贝库文件和测试程序到NanoPi的文件系统上
+
Please copy the library files and test program to the NanoPi
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cp install/usr/usr/bin/* nanopi_rootfs/usr/usr/bin/
 
$ cp install/usr/usr/bin/* nanopi_rootfs/usr/usr/bin/
Line 106: Line 316:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
然后启动NanoPi，在Debian的shell终端中执行如下命令运行模块Matrix-Temperature_and_Humidity_Sensor的测试程序 <br>
+
Power on the NanoPi and run the following command in Debian's terminal <br>
−
注意：此模块并不支持热插拔，启动系统前需要确保硬件正常连接。
+
Note: this module is not plug and play therefore before running the module please make sure it is connected to a NanoPi.
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ matrix-temp_humidity
 
$ matrix-temp_humidity
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
===代码展示===
+
===Code Sample===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
 
int main(int argc, char ** argv)
 
int main(int argc, char ** argv)
Line 149: Line 359:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与Tiny4412连接使用==
+
==Connect to Tiny4412==
−
===准备工作===
+
===Preparations===
−
参考Tiny4412光盘里的《友善之臂Ubuntu使用手册》，在Tiny4412上运行UbuntuCore系统，然后在主机PC上安装并使用相应的编译器。<br>
+
Please refer to the Tiny4412's user's manual to install a UbuntuCore on the Tiny4412 and install an appropriate cross compiler on a PC.<br>
−
注意：只能使用Tiny4412SDK-1506的底板。
+
Note: only the Tiny4412SDK-1506 carrier board can work with this module.
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-Temperature_and_Humidity_Sensor和Tiny4412 <br>
+
Please refer to the following diagram to connect the Matrix-Temperature_and_Humidity_Sensor to the Tiny4412 <br>
 
[[File:matrix-temperature_and_humidity_sensor_tiny4412.jpg|frameless|600px|matrix-temperature_and_humidity_sensor_tiny4412]]
 
[[File:matrix-temperature_and_humidity_sensor_tiny4412.jpg|frameless|600px|matrix-temperature_and_humidity_sensor_tiny4412]]
  
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 170: Line 380:
 
|}
 
|}
  
−
===编译测试程序===
+
===Compile Test Program===
−
进入Matrix代码仓库，切换到tiny4412分支
+
Please login the Matrix hub and enter the matrix-tiny4412 branch
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cd matrix
 
$ cd matrix
Line 177: Line 387:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
编译Matrix配件代码
+
Compile the matrix code
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- clean
Line 183: Line 393:
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- install
 
$ make CROSS_COMPILE=arm-linux-gnueabihf- install
 
</syntaxhighlight>
 
</syntaxhighlight>
−
注意：请确保你的主机PC当前使用的交叉编译器为Tiny4412-UbuntuCore配套的arm-linux-gnueabihf-gcc-4.7.3。<br>
+
Note: please make sure to install the cross compiler "arm-linux-gnueabihf-gcc-4.7.3" on your PC, which is used to compile files for the Tiny4412-UbuntuCore.<br>
−
编译出来的库文件位于install/lib目录下，而测试程序则位于install/usr/usr/bin目录下，模块Matrix-Temperature_and_Humidity_Sensor对应的测试程序为matrix-temp_humidity。
+
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Temperature_and_Humidity_Sensor" module is "matrix-temp_humidity".
  
−
===运行测试程序===
+
===Run Test Program===
−
拷贝库文件和测试程序到Tiny4412的UbuntuCore的文件系统上
+
Please copy the library files and test program to the Tiny4412
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ cp install/usr/usr/bin/* tiny4412_rootfs/usr/usr/bin/
 
$ cp install/usr/usr/bin/* tiny4412_rootfs/usr/usr/bin/
Line 193: Line 403:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
然后启动Tiny4412，在UbuntuCore的shell终端中执行如下命令运行模块Matrix-Temperature_and_Humidity_Sensor的测试程序 <br>
+
Power on the Tiny4412 and run the following command in UbuntuCore's terminal <br>
−
注意：此模块并不支持热插拔，启动系统前需要确保硬件正常连接。
+
Note: this module is not plug and play therefore before running the module please make sure it is connected to a Tiny4412.
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
 
$ matrix-temp_humidity
 
$ matrix-temp_humidity
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
===代码展示===
+
===Code Sample===
 
<syntaxhighlight lang="c">
 
<syntaxhighlight lang="c">
 
int main(int argc, char ** argv)
 
int main(int argc, char ** argv)
Line 236: Line 446:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
==与RaspberryPi连接使用==
+
==Connect to RaspberryPi==
  
−
==与Arduino连接使用==
+
==Connect to Arduino==
 +
--->
  
−
==相关资料==
+
==Resources==
 
[http://akizukidenshi.com/download/ds/aosong/DHT11.pdf DHT11.pdf]
 
[http://akizukidenshi.com/download/ds/aosong/DHT11.pdf DHT11.pdf]
 +
 +
==Update Log==
 +
===Feb-23-2016===
 +
* Added the description for "NanoPi 2 branch" in Section 4
 +
* Added Section 5: Connect to NanoPi 2
 +
===June-24-2016===
 +
* Re-organized and simplified wiki
  
  

Latest revision as of 15:50, 24 June 2016

查看中文

1 Introduction

Temperature and Humidity Sensor
  • The Matrix-Temperature_and_Humidity_Sensor module is used to detect temperature and humidity.
  • It utilizes the DHT11 temperature and humidity sensor. Its humidity range is 20% - 80% and the accuracy is 5%. Its temperature range is 0℃ - 50℃ and the accuracy is ±2℃.

2 Features

  • Humidity range: 20 - 80%RH, Temperature range 0 ~ 50℃
  • Accuracy of humidity: +-5%RH, accuracy of temperature: +-2℃
  • One wire communication
  • 2.54 mm spacing pin
  • PCB dimension (mm): 16 x 32

温湿度传感器PCB

Pin Description:

Pin Description
S GPIO
V Supply Voltage 5V
G Ground

3 Basic Device Operation

The DHT11 module uses a simplified single-bus serial communication. DATA controls communication and synchronization between the microprocessor and DHT11. A data transfer takes 4ms. The data format contains an integer part and a decimal part. The basic operation is as follows:

  • a transmission of 40 data, the high first-out
  • data format: 8bit humidity integer data + 8bit the Humidity decimal data
  • 8bit temperature integer data + 8bit fractional temperature data
  • 8 bit parity bit
  • If a transmission is successful the “8bit humidity integer data + 8bit humidity decimal data +8 bit temperature integer data + 8bit temperature fractional data” 8bit checksum is equal to the results of the last eight.
  • After the user host (MCU) sends a signal DHT11 is converted from low-power mode to high-speed mode, until the host begins to signal the end. Then DHT11 sends a response signal to send 40bit data, and trigger a letter collection. If DHT11 doesn't receive a signal from the host it will not begin a letter collection. After the letter collection is done DHT11 will turn to low power mode.


4 Applications

4.1 Connect to NanoPi M1

Refer to the following connection diagram to connect the module to the NanoPi M1:
Matrix-Temperature_and_Humidity_Sensor_nanopi_m1

Connection Details:

Matrix-Temperature_and_Humidity_Sensor NanoPi M1
S Pin7
V Pin4
G Pin6

4.2 Connect to NanoPi 2

Refer to the following connection diagram to connect the module to the NanoPi 2:
Matrix-Temperature_and_Humidity_Sensor_nanopi_2

Connection Details:

Matrix-Temperature_and_Humidity_Sensor NanoPi 2
S Pin7
V Pin4
G Pin6

4.3 Connect to NanoPi M2 / NanoPi 2 Fire

Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire:
Matrix-Temperature_and_Humidity_Sensor_nanopi_m2

Connection Details:

Matrix-Temperature_and_Humidity_Sensor NanoPi M2
S Pin7
V Pin4
G Pin6

4.4 Connect to NanoPC-T2

Refer to the following connection diagram to connect the module to the NanoPC-T2:
Matrix-Temperature_and_Humidity_Sensor_NanoPC-T2

Connection Details:

Matrix-Temperature_and_Humidity_Sensor NanoPC-T2
S Pin15
V Pin29
G Pin30

5 Compile & Run Test Program

Boot your ARM board with Debian and copy the matrix code: 

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

If your cloning is done successfully a "matrix" directory will be generated.

Compile and install Matrix: 

$ cd matrix
$ make && make install

Run test program: 

$ matrix-temp_humidity

Note: this module is not plug and play therefore before running the module please make sure it is connected to an ARM board.
Here is what you should observe:

The humidity is 35000
The temperature is 26000

The module successfully read the environment's humidity and temperature values.

6 Code Sample

This Matrix code sample can work with all the ARM boards mentioned in this module's wiki. The name of this code sample is "matrix-temperature_and_humidity_sensor". Here is its source code: 

int main(int argc, char ** argv)
{
    int ret = -1;
    int dhtTemp=0, dhtHdty=0, board;
    char modStr[BUF_SIZE];
    int pin = GPIO_PIN(7);
 
    if ((board = boardInit()) < 0) {
        printf("Fail to init board\n");
        return -1;
    }    
    if (board == BOARD_NANOPI_T2)
        pin = GPIO_PIN(15);
 
    sprintf(modStr, "modprobe %s gpio=%d", DRIVER_MODULE, pintoGPIO(pin));
    system(modStr);
    if ((ret = dht11Read(DHT_HUMIDITY, &dhtHdty)) != -1) {
        printf("The humidity is %d\n", dhtHdty);
    } else {
        printf("Faided to get humidity\n");
    }
    if ((ret = dht11Read(DHT_TEMP, &dhtTemp)) != -1) {
        printf("The temperature is %d\n", dhtTemp);
    } else {
        printf("Faided to get temperature\n");
    }
    system("rmmod "DRIVER_MODULE);
    return ret;
}

For more details about this APIs called in this code sample refer to Matrix API reference manual


7 Resources

DHT11.pdf

8 Update Log

8.1 Feb-23-2016

  • Added the description for "NanoPi 2 branch" in Section 4
  • Added Section 5: Connect to NanoPi 2

8.2 June-24-2016

  • Re-organized and simplified wiki


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