Difference between revisions of "Matrix - Analog to Digital Converter"

From FriendlyELEC WiKi
Jump to: navigation, search
(→‎Download Matrix Source Code)
(→‎Applications)
 
(23 intermediate revisions by 2 users not shown)
Line 18: Line 18:
 
* 2.54 mm spacing pin
 
* 2.54 mm spacing pin
 
* PCB dimension (mm): 16 x 24
 
* PCB dimension (mm): 16 x 24
−
[[File:adcpcb.png|frameless|400px|模数PCB]]
+
[[File:adcpcb.png|frameless|400px|Analog to Digital PCB]]
  
 
* Pin Description:
 
* Pin Description:
Line 51: Line 51:
 
3. The on-chip D/A converter and a high-gain comparator are used temporarily during an A/D conversion cycle. An A/D conversion cycle is always started after sending a valid read mode address to a PCF8591 device. The A/D conversion cycle is triggered at the trailing edge of the acknowledge clock pulse and is executed while transmitting the result of the previous conversion。 <br>
 
3. The on-chip D/A converter and a high-gain comparator are used temporarily during an A/D conversion cycle. An A/D conversion cycle is always started after sending a valid read mode address to a PCF8591 device. The A/D conversion cycle is triggered at the trailing edge of the acknowledge clock pulse and is executed while transmitting the result of the previous conversion。 <br>
  
 +
 +
==Applications==
 +
===Connect to NanoPi M1===
 +
Refer to the following connection diagram to connect the module to the NanoPi M1<br>
 +
[[File:Matrix-Analog_to_Digital_Converter_nanopi_m1.jpg|frameless|600px|Matrix-Analog_to_Digital_Converter_nanopi_m1]]
 +
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Analog_to_Digital_Converter || NanoPi M1     
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || Pin6
 +
|}
 +
 +
===Connect to NanoPi 2===
 +
Refer to the following connection diagram to connect the module to the NanoPi 2:<br>
 +
[[File:Matrix-Analog_to_Digital_Converter_nanopi_2.jpg|frameless|600px|Matrix-Analog_to_Digital_Converter_nanopi_2]]
 +
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Analog_to_Digital_Converter || NanoPi 2     
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || 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-Analog_to_Digital_Converter_nanopi_M2.jpg|frameless|600px|Matrix-Analog_to_Digital_Converter_nanopi_M2]]
 +
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Analog_to_Digital_Converter || NanoPi M2     
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || Pin6
 +
|}
 +
 +
===Connect to NanoPC-T2===
 +
Refer to the following connection diagram to connect the module to the NanoPC-T2<br>
 +
[[File:Matrix-Analog_to_Digital_Converter_NanoPC-T2.jpg|frameless|600px|Matrix-Analog_to_Digital_Converter_NanoPC-T2]]
 +
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Analog_to_Digital_Converter || NanoPC-T2
 +
|-
 +
|SDA    || Pin6
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin29
 +
|-
 +
|GND    || 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-adc
 +
</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 channel0 value is 2460
 +
</syntaxhighlight>
 +
When Channel 0 is connected to 5V its value reaches the maximum: 2550. When it is grounded its value is 0.
 +
 +
==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-analog_to_digital_converter". Here is its source code:
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int i = 0;
 +
    int value = 0;
 +
    int channel = 0;
 +
 +
    if (boardInit() < 0) {
 +
        printf("Fail to init board\n");
 +
        return -1;
 +
    }
 +
   
 +
    if (argc == 2)
 +
        channel = atoi(argv[1]);
 +
    system("modprobe "DRIVER_MODULE);
 +
    signal(SIGINT, intHandler);
 +
    for (i=0; i<ADC_READ_TIMES; i++) {
 +
        if (pcf8591Read(channel, &value) != -1) {
 +
            printf("The channel%d value is %d\n", channel, value);
 +
        } else {
 +
            printf("Fail to get channel%d value\n", channel);
 +
        }
 +
    }
 +
    system("rmmod "DRIVER_MODULE);
 +
   
 +
    return 0;
 +
}
 +
</syntaxhighlight>
 +
For more details about this APIs called in this code sample refer to [[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 - git://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>
 
Each branch in this hub contains the matrix modules' code samples for a board that the matrix modules can work with.<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 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 tiny4412 branch contains the matrix modules' code samples for the Tiny4412
 
* The raspberrypi branch contains the matrix modules' code samples for the RaspberryPi
 
* The raspberrypi branch contains the matrix modules' code samples for the RaspberryPi
Line 66: Line 200:
 
Clone the matrix code from GitHub
 
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>
 
</syntaxhighlight>
 
If this is successful a "matrix" directory will be generated, which will contain all the matrix modules' code samples.
 
If this is successful a "matrix" directory will be generated, which will contain all the matrix modules' code samples.
  
−
==与NanoPi连接使用==
+
==Connect to NanoPi 2==
−
===准备工作===
+
===Hardware Connection===
−
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 refer to the following connection diagram to connect the Matrix-Analog_to_Digital_Converter to the NanoPi 2:<br>
−
注意：必须使用nanopi-v4.1.y-matrix分支编译出来的内核。<br>
+
[[File:Matrix-Analog_to_Digital_Converter_nanopi_2.jpg|frameless|600px|Matrix-Analog_to_Digital_Converter_nanopi_2]]
−
下载NanoPi内核源代码并编译
+
 
 +
Connection Details:
 +
{| class="wikitable"
 +
|-
 +
|Matrix-Analog_to_Digital_Converter || NanoPi 2     
 +
|-
 +
|SDA    || Pin3
 +
|-
 +
|SCL    || Pin5
 +
|-
 +
|5V    || Pin4
 +
|-
 +
|GND    || 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 NanoPi2.<br>
 +
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Analog_to_Digital_Converter" module is "matrix-adc".<br>
 +
The driver is under the modules directory and its 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 driver, 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.<br>
 +
<syntaxhighlight lang="bash">
 +
$ cd /modules
 +
$ insmod pcf8591.ko
 +
</syntaxhighlight>
 +
 
 +
Start the matrix-adc program.<br>
 +
<syntaxhighlight lang="bash">
 +
$ matrix-adc
 +
</syntaxhighlight>
 +
Note: this module is not plug and play therefore before running the module please make sure it is connected to a NanoPi 2.<br>
 +
Here is what you should expect:<br>
 +
[[File:matrix-adc_result.png|frameless||matrix-adc_result]] <br>
 +
The program reads Channel 0's value
 +
 
 +
===Code Sample===
 +
<syntaxhighlight lang="c">
 +
int main(int argc, char ** argv)
 +
{
 +
    int i = 0;
 +
    int value = 0;
 +
    int channel = 0;
 +
 
 +
    if (argc == 2) {
 +
        channel = atoi(argv[1]);
 +
    }
 +
   
 +
    for (i=0; i<ADC_READ_TIMES; i++) {
 +
        if (pcf8591Read(channel, &value) != -1) {
 +
            printf("channel%d value=%d\n", channel, value);
 +
        } else {
 +
            printf("Fail to get channel%d value\n", channel);       
 +
        }
 +
        usleep(10000);
 +
    }
 +
    return 0;
 +
}
 +
</syntaxhighlight>
 +
 
 +
==Connect to NanoPi==
 +
===Preparations===
 +
Please install a Debian on a NanoPi and an appropriate cross compiler on a PC. Please refer to wiki:[[NanoPi/zh|NanoPi]] <br>
 +
Compile a NanoPi kernel. Note: please use the kernel's source code from the nanopi-v4.1.y-matrix branch.<br>
 
<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 84: Line 301:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
===硬件连接===
+
===Hardware Connection===
−
参考下图连接模块Matrix-Analog_to_Digital_Converter和NanoPi <br>
+
Please refer to the following connection diagram to connect the Matrix-Analog_to_Digital_Converter to the NanoPi <br>
 
[[File:matrix-analog_to_digital_converter_nanopi.jpg|frameless|600px|matrix-analog_to_digital_converter_nanopi]]
 
[[File:matrix-analog_to_digital_converter_nanopi.jpg|frameless|600px|matrix-analog_to_digital_converter_nanopi]]
  
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 102: Line 319:
 
|}
 
|}
  
−
===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 109: Line 326:
 
</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 115: Line 332:
 
$ 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/bin目录下，模块Matrix-Analog_to_Digital_Converter对应的测试程序为matrix-analog_to_digital_converter。<br>
+
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Analog_to_Digital_Converter" module is "matrix-adc".<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/bin/* nanopi_rootfs/usr/bin/
 
$ cp install/usr/bin/* nanopi_rootfs/usr/bin/
Line 125: Line 342:
 
</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-Analog_to_Digital_Converter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-analog_to_digital_converter
+
$ matrix-adc
 
</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 161: Line 378:
 
</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-Analog_to_Digital_Converter和Tiny4412 <br>
+
Please refer to the following diagram to connect the Matrix-Analog_to_Digital_Converter to the Tiny4412 <br>
 
[[File:matrix-analog_to_digital_converter_tiny4412.jpg|frameless|600px|matrix-analog_to_digital_converter_tiny4412]]
 
[[File:matrix-analog_to_digital_converter_tiny4412.jpg|frameless|600px|matrix-analog_to_digital_converter_tiny4412]]
  
−
连接说明：
+
Connection Details:
 
{| class="wikitable"
 
{| class="wikitable"
 
|-
 
|-
Line 184: Line 401:
 
|}
 
|}
  
−
===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 191: Line 408:
 
</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 197: Line 414:
 
$ 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/bin目录下，模块Matrix-Analog_to_Digital_Converter对应的测试程序为matrix-analog_to_digital_converter。
+
Generated library files are under the "install/lib" directory. Applications are under the "install/usr/bin" directory. The test program for the "Matrix-Analog_to_Digital_Converter" module is "matrix-adc".
  
−
===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/bin/* tiny4412_rootfs/usr/bin/
 
$ cp install/usr/bin/* tiny4412_rootfs/usr/bin/
Line 207: Line 424:
 
</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-Analog_to_Digital_Converter的测试程序
+
Power on the Tiny4412 and run the following command in UbuntuCore's terminal
 
<syntaxhighlight lang="bash">
 
<syntaxhighlight lang="bash">
−
$ matrix-analog_to_digital_converter
+
$ matrix-adc
 
</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 242: Line 459:
 
</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://www.nxp.com/documents/data_sheet/PCF8591.pdf PCF8591.pdf]
 
[http://www.nxp.com/documents/data_sheet/PCF8591.pdf PCF8591.pdf]
 +
 +
==Update Log==
 +
===Feb-19-2016===
 +
* Added Section 5
 +
 +
===June-17-2016===
 +
* Re-organized and simplified wiki
  
  

Latest revision as of 10:28, 19 June 2016

查看中文

1 Introduction

Analog to Digital Converter
  • The Matrix-Analog_to_Digital_Converter is a single-chip, single-supply low-power 8-bit CMOS data acquisition device.
  • It utilizes the PCF8591 chip with four analog inputs, one analog output and a serial I2C-bus interface. Three address pins A0, A1 and A2 are used for programming the hardware address, allowing

the use of up to eight devices connected to the I2C-bus without additional hardware. Address, control and data to and from the device are transferred serially via the two-line bidirectional I2C-bus. The maximum conversion rate is given by the maximum speed of the I2C-bus.

  • The I2C hardware address is configured to 1001000x
  • The operating supply voltage is from 2.5V to 6.0V，Among the 2.54 mm spacing pin header the 5V pin is the supply voltage. If you need 0 - 3.3V analog signals and keep the acquisition resolution you can connect it to a 3.3V supply voltage.

2 Features

  • Wide range supply voltage: 2.5V - 6.0V
  • I2C interface: 3.3V/5V
  • 8-bit A/D x 4
  • 8-bit D/A x 1
  • Small and easy to be used in various situations
  • 2.54 mm spacing pin
  • PCB dimension (mm): 16 x 24

Analog to Digital PCB

  • Pin Description:
Pin Description
SDA I2C SDA
SCL I2C SCL
5V Supply Voltage 5V
GND Ground
AOUT Analog Output
A3 Analog Input3
A2 Analog Input2
A1 Analog Input1
A0 Analog Input0

3 Basic Device Operation

The PCF8591's I2C-bus is for bidirectional, two-line communication between different ICs or modules. The two lines are a Serial DAta line (SDA) and a Serial CLock line (SCL). Both lines must be connected to a positive supply via a pull-up resistor. Data transfer may be initiated only when the bus is not busy. The AINT0 - AINT4 pins are analog inputs which can be configured to single-ended or differential inputs. The supply voltage is 0 - VDD.
1. Each PCF8591 device in an I2C-bus system is activated by sending a valid address to the device. The address consists of a fixed part and a programmable part. The programmable part must be set according to the address pins A0, A1 and A2. The address is always sent as the first byte after the start condition in the I2C-bus protocol. The last bit of the address byte is the read/write-bit which sets the direction of the following data transfer.
2. The second byte sent to a PCF8591 device is stored in its control register and is required to control the device function. The upper nibble of the control register is used for enabling the analog output, and for programming the analog inputs as single-ended or differential inputs. The lower nibble selects one of the analog input channels defined by the upper nibble.
3. The on-chip D/A converter and a high-gain comparator are used temporarily during an A/D conversion cycle. An A/D conversion cycle is always started after sending a valid read mode address to a PCF8591 device. The A/D conversion cycle is triggered at the trailing edge of the acknowledge clock pulse and is executed while transmitting the result of the previous conversion。


4 Applications

4.1 Connect to NanoPi M1

Refer to the following connection diagram to connect the module to the NanoPi M1
Matrix-Analog_to_Digital_Converter_nanopi_m1

Connection Details:

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

4.2 Connect to NanoPi 2

Refer to the following connection diagram to connect the module to the NanoPi 2:
Matrix-Analog_to_Digital_Converter_nanopi_2

Connection Details:

Matrix-Analog_to_Digital_Converter NanoPi 2
SDA Pin3
SCL Pin5
5V Pin4
GND 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-Analog_to_Digital_Converter_nanopi_M2

Connection Details:

Matrix-Analog_to_Digital_Converter NanoPi M2
SDA Pin3
SCL Pin5
5V Pin4
GND Pin6

4.4 Connect to NanoPC-T2

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

Connection Details:

Matrix-Analog_to_Digital_Converter NanoPC-T2
SDA Pin6
SCL Pin5
5V Pin29
GND 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-adc

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 channel0 value is 2460

When Channel 0 is connected to 5V its value reaches the maximum: 2550. When it is grounded its value is 0.

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-analog_to_digital_converter". Here is its source code: 

int main(int argc, char ** argv)
{
    int i = 0;
    int value = 0;
    int channel = 0;
 
    if (boardInit() < 0) {
        printf("Fail to init board\n");
        return -1;
    }
 
    if (argc == 2)
        channel = atoi(argv[1]);
    system("modprobe "DRIVER_MODULE);
    signal(SIGINT, intHandler);
    for (i=0; i<ADC_READ_TIMES; i++) {
        if (pcf8591Read(channel, &value) != -1) {
            printf("The channel%d value is %d\n", channel, value);
        } else {
            printf("Fail to get channel%d value\n", channel);
        }
    }
    system("rmmod "DRIVER_MODULE);
 
    return 0;
}

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



7 Resources

PCF8591.pdf

8 Update Log

8.1 Feb-19-2016

  • Added Section 5

8.2 June-17-2016

  • Re-organized and simplified wiki


Retrieved from "https://wiki.friendlyelec.com/wiki/index.php?title=Matrix_-_Analog_to_Digital_Converter&oldid=6106"