View source for KS0213 Keyestudio RPI GPIO-PCF8591 Shield

==keyestudio RPI GPIO-PCF8591 Shield==
<br>[[File:ks0213-1.png|500px|frameless|thumb]]<br>

==Introduction==
There's no AD/DA function on the Raspberry Pi GPIO interface, this may trouble you in the Pi development. However, it won't be a problem anymore. The RPI GPIO-PCF8591 Shield allows you to add high-precision AD/DA functions to the Raspberry Pi.<br>
The PCF8591 features four-8-bit analog to digital converters and a single 8-bit digital to analog converter.This will operate through the I2C interface on the Raspberry Pi.<br>

==Connection Diagram ==
Plug it directly into Raspberry Pi to start your works as shown in below figure. 
<br>[[File:ks0213-2.png|500px|frameless|thumb]]<br>

==Sample Code==
<pre>
DA(Digital to Analog) Source Code：
#include <wiringPi.h>
#include <pcf8591.h>
#include <stdio.h>

#define Address 0x48
#define BASE 64          //DA Output
#define A0 BASE+0
#define A1 BASE+1
#define A2 BASE+2
#define A3 BASE+3

int main(void)
{
    unsigned char value;
	wiringPiSetup();
	pcf8591Setup(BASE,Address);    //configuration pcf8591	

	while(1)
	{		
               analogWrite(BASE,value);      //write the value output on AOUT interface
               printf("AOUT:%d\n",value);     //print that value
               delay(50);	
	}
}

AD(Analog to Digital) Source Code：
#include <wiringPi.h>
#include <pcf8591.h>
#include <stdio.h>

#define Address 0x48         //pcf8591 address 
#define BASE 64
#define A0 BASE+0           //A0 input
#define A1 BASE+1           //A1 input
#define A2 BASE+2           //A2 input
#define A3 BASE+3           //A3 input
int main(void)
{
    unsigned char value;
	wiringPiSetup();
	pcf8591Setup(BASE,Address);        //configurationpcf8591
	
	while(1)
	{
               value=analogRead(A0);     // read A0 value          
               printf("A0:%d\n",value);  // print A0 value
               delay(100);	
	}
}
</pre>


==Program Writing==
===1.Install Wiringpi Library===
Wiring Pi is a library. WiringPi supports analog reading and writing, and while there is no native analog hardware on a Pi by default, modules are provided so other A/D and D/A devices can be implemented relatively easily. We will provide a Wiringpi installation package or click on this 
URL: https://projects.drogon.net/raspberry-pi/wiringpi/download-and-install/ (it should open in a new page) to download the latest version. This will download a .tar file with a name like wiringPi-b0a60c3.tar. Then copy the file and put it into the raspberry pi file as shown in below figure:
<br>[[File:ks0213-3.png|500px|frameless|thumb]]<br>

Type in this command to unzip the source code and install:<br>
tar xfz wiringPi-98bcb20.tar.gz<br>
cd wiringPi-98bcb20<br>
./build<br>
Note that the actual file name will be different (may not be 98bcb20) – you will have to check the name and adjust accordingly. Here is the interface after installing WiringPi as shown in below figure.<br>
<br>[[File:ks0213-4.png|500px|frameless|thumb]]<br>

WirtingPi includes a set of gpio commands to control the GPIO pins of the Raspberry Pi. Type in the command to check the installation:
gpio -v<br>
gpio readall<br>
The interface as shown in below figure means complete installation.
<br>[[File:ks0213-5.png|500px|frameless|thumb]]<br>

===2.Enable I2C Utility===
The I2C bus allows multiple devices to be connected to your Raspberry Pi. Before using I2C it needs to be configured. Run this command: sudo raspi-config and follow the prompts to install I2C. Now complete the following steps :<br>
Select “9 Advanced Options”<br>
Select “A6 I2C”<br>
The screen will ask if you want the ARM I2C interface to be enabled :<br>
Select “Yes”<br>
Select “Ok”<br>
Select “Finish” to return to the command line<br>
When you next reboot the I2C module will be loaded.<br>

===3.Programming===
Copy the file pcf8591 provided by us and put it into your pi directory through winSCP. Next , type this command: cd pcf8591 to go inside the pcf8591 folder. Then type this command: make  to make an executable file. This means this is the file we run to launch the program.  <br>
Finally type this: sudo ./TTP229 to launch the program. <br>

==Result==
DA source code makes AOUT interface output 0-5V voltage; the pi will prints digital value among 0-255 on the terminal after reading out voltage set by AD source code.

==Documents ==

'''PDF File:'''

https://drive.google.com/open?id=1KGHWkoRwcH26PSLvVD6jLZxRa5-qIp-r

'''Installation Package Download:'''

https://drive.google.com/open?id=18pp8aNUe05B6EzyphTb9JLnE6gQaBOL6

''' Source Code Download :'''

https://drive.google.com/open?id=1bwUSsxDyB-st2qaLyK2phvpbelvUph9S

== Buy From ==
http://www.keyestudio.com/keyestudio-rpi-gpio-pcf8591-shield.html


[[Category:Raspberry Pi]]