BPI I2C GPIO extend module - Revision history

Sinovoip at 12:37, 14 May 2018

2018-05-14T12:37:01Z

Sinovoip: /* Hardware */

2018-05-14T12:35:21Z

‎Hardware

Sinovoip at 12:32, 14 May 2018

2018-05-14T12:32:32Z

Sinovoip: /* Hardware */

2018-05-14T12:32:09Z

‎Hardware

Sinovoip: /* How to use */

2018-05-14T12:31:44Z

‎How to use

Sinovoip at 12:30, 14 May 2018

2018-05-14T12:30:41Z

Sinovoip at 12:30, 14 May 2018

2018-05-14T12:30:27Z

Sinovoip at 12:29, 14 May 2018

2018-05-14T12:29:23Z

Sinovoip: /* How to use */

2018-05-14T12:26:36Z

‎How to use

Sinovoip: /* Product Parameters */

2018-05-14T12:23:11Z

‎Product Parameters

@@ Line 49: / Line 49: @@
 *5. I2C-address selection jumper
 Insert the module that the silk screen says “BPI IN”. Pay attention don’t make the direction reversed! The correct direction of insert module is above the Banana Pi’s PCB; EXT0-EXT7 are expand GPIO，user can use DuPont Line to connection peripheral. The header which near silk screen write ”EXT” expand GPIO of Banana Pi, user can cascade the other module or the same module. If you want switch the electric level, just setup the jumper
 [[File:Connect.jpg]]
 The PCF8574/74A provides general-purpose remote I/O expansion via the two-wire bidirectional I2C-bus (serial clock (SCL), serial data (SDA)).

@@ Line 36: / Line 36: @@
 [[File:I2c1.png]]
 ==Port==
@@ Line 61: / Line 65: @@
 The active LOW open-drain interrupt output (INT) can be connected to the interrupt logic of the microcontroller and is activated when any input state differs from its corresponding input port register state. It is used to indicateto the microcontroller that an input state has changed and the device needs to be interrogated without the microcontroller continuously polling the input register via the I2C-bus.
 The internal Power-On Reset (POR) initializesthe I/Os as inputs with a weak internal pull-up 100uA current source.
 Address Table：
-![](i2c2.png)
+[[File:I2c2.png]]
 Timing Diagram：
-![](i2c3.png)
+[[File:I2c3.png]]
 Testbench：
@@ Line 80: / Line 85: @@
 *7. Finish test
 **More information please check：**

@@ Line 44: / Line 44: @@
 *4. Electric level selection jumper
 *5. I2C-address selection jumper
 Insert the module that the silk screen says “BPI IN”. Pay attention don’t make the direction reversed! The correct direction of insert module is above the Banana Pi’s PCB; EXT0-EXT7 are expand GPIO，user can use DuPont Line to connection peripheral. The header which near silk screen write ”EXT” expand GPIO of Banana Pi, user can cascade the other module or the same module. If you want switch the electric level, just setup the jumper

← Older revision		Revision as of 12:32, 14 May 2018
Line 34:		Line 34:

	==Product Specification==		==Product Specification==
		+
	[[File:I2c1.png]]		[[File:I2c1.png]]

@@ Line 48: / Line 48: @@
 Insert the module that the silk screen says “BPI IN”. Pay attention don’t make the direction reversed! The correct direction of insert module is above the Banana Pi’s PCB; EXT0-EXT7 are expand GPIO，user can use DuPont Line to connection peripheral. The header which near silk screen write ”EXT” expand GPIO of Banana Pi, user can cascade the other module or the same module. If you want switch the electric level, just setup the jumper
-![](connect.jpg)
+[[File:Connect.jpg]]
 '''More Information：'''

← Older revision		Revision as of 12:30, 14 May 2018
Line 1:		Line 1:
−
−	~~Product Specification：~~
−
−	~~![](i2c1.png)~~

	=Product Overview=		=Product Overview=

@@ Line 1: / Line 1: @@
 **Product Specification：**
@@ Line 40: / Line 36: @@
 =Hardware=
 ==Port==

← Older revision		Revision as of 12:29, 14 May 2018
Line 9:		Line 9:

	=Product Overview=		=Product Overview=
		+
		+	[[File:I2c_gpio_extend_1.jpg\|thumb\|Overview ]]

	This module is designed specifically for expand for the GPIO of the Banana Pi a which can effectively solve the banana send IO port insufficient. It use PCF8574 chip to expand 8 Bidirectional IO. The module connection to the Banana Pi through I2C bus. There are 8 I2C address in the module and user can choose one of them through setup the “ADDR” jumper. User also can choose 5V or 3.3V electric level. Module with isolation protection, can effectively prevent external high voltage damage to the Banana Pi. Multiple module can cascade.		This module is designed specifically for expand for the GPIO of the Banana Pi a which can effectively solve the banana send IO port insufficient. It use PCF8574 chip to expand 8 Bidirectional IO. The module connection to the Banana Pi through I2C bus. There are 8 I2C address in the module and user can choose one of them through setup the “ADDR” jumper. User also can choose 5V or 3.3V electric level. Module with isolation protection, can effectively prevent external high voltage damage to the Banana Pi. Multiple module can cascade.

@@ Line 53: / Line 53: @@
 ![](connect.jpg)
-**More Information：**
+'''More Information：'''
 The PCF8574/74A provides general-purpose remote I/O expansion via the two-wire bidirectional I2C-bus (serial clock (SCL), serial data (SDA)).
@@ Line 70: / Line 70: @@
 ![](i2c2.png)
-**Timing Diagram：**
+Timing Diagram：
 ![](i2c3.png)
-**Testbench：**
+Testbench：
-. Use: sudo i2cdetect –y –a 1check the I2C-address
+*1. Use: sudo i2cdetect –y –a 1check the I2C-address
-. Use wiringPi API, initialize module
+*2. Use wiringPi API, initialize module
-. Setup IO to OUTPUT mode, 5V high level and check the level of the state with a multimeter
+*3. Setup IO to OUTPUT mode, 5V high level and check the level of the state with a multimeter
-. Setup IO to OUTPUT mode, 3V high level and check the level of the state with a multimeter
+*4. Setup IO to OUTPUT mode, 3V high level and check the level of the state with a multimeter
-. Setup IO to INPUT mode, input 5V high level and check the IO status through wiringPi
+*5. Setup IO to INPUT mode, input 5V high level and check the IO status through wiringPi
-. Setup IO to INPUT mode, input 3V high level and check the IO status through wiringPi
+*6. Setup IO to INPUT mode, input 3V high level and check the IO status through wiringPi
-. Finish test
+*7. Finish test
 **Schematic diagram：**
@@ Line 92: / Line 92: @@
 http://www.nxp.com/products/interface_and_connectivity/i2c/i2c_general_purpose_i_o/PCF8574T.html
-**How to use I2C module on BPI-M3：**
+=How to use=
 OS: BPI-M3 Ubuntu15.10 (Kernel3.4)
 Version: 1.0 HDMI
 Step 1: Download WiringPI
-```
+ $ git clone https://github.com/BPI-SINOVOIP/BPI-WiringPi.git1111 -b BPI_M3
-$ git clone https://github.com/BPI-SINOVOIP/BPI-WiringPi.git1111 -b BPI_M3
+ $ cd BPI-WiringPi
-$ cd BPI-WiringPi
+ $ chmod +x ./build
-$ chmod +x ./build
+ $ sudo ./build```
 Step 2:Check the BPI I2C GPIO extend(PCF8574) device to see if it's on track.(address 0x27)
 (I2c port number for M3: 2 )
-```
+ sudo su
-sudo su
+ i2cdetect -y 2
-i2cdetect -y 2
+ .0 1 2 3 4 5 6 7 8 9 a b c d e f
-.0 1 2 3 4 5 6 7 8 9 a b c d e f
+: -- -- -- -- -- -- -- -- -- -- -- -- --
-: -- -- -- -- -- -- -- -- -- -- -- -- --
+: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+: -- -- -- -- -- -- -- 27 -- -- -- -- -- -- -- --
-: -- -- -- -- -- -- -- 27 -- -- -- -- -- -- -- --
+: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 : -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 : -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 : -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
-: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+: -- -- -- -- -- -- -- --```
 Step 3 : Copy smaple code to i2c_pcf8574.c file
-```$ sudo vi i2c_pcf8574.c```
+ $ sudo vi i2c_pcf8574.c
 Step 4 : Compile i2c_pcf8574.c
-```$ gcc -o i2c_pcf8574 i2c_pcf8574.c -l wiringPi```
+ $ gcc -o i2c_pcf8574 i2c_pcf8574.c -l wiringPi
 Step 5: Run i2c_pcf8574
-```$ sudo ./i2c_pcf8574```
+ $ sudo ./i2c_pcf8574
 Video Demo on youtube:
@@ Line 138: / Line 138: @@
 Sample Code:
-```
-#include <wiringPi.h>
+ #include <wiringPi.h>
-#include <pcf8574.h>
+ #include <pcf8574.h>
-#include <stdio.h>
+ #include <stdio.h>
-int main()
+ int main()
-−
+ {
-int i;
+ int i;
-pcf8574Setup(100,0x27);
+ pcf8574Setup(100,0x27);
-for(i=0;i<8;i++) pinMode(100+i,OUTPUT);
+ for(i=0;i<8;i++) pinMode(100+i,OUTPUT);
-while(1)
+ while(1)
-−
+ {
-i = 0;
+ i = 0;
-for(i=0;i<=8;i++)
+ for(i=0;i<=8;i++)
-−
+ {
-printf("Current LED = %d\n",100+i);
+ printf("Current LED = %d\n",100+i);
-digitalWrite((100+i),HIGH);
+ digitalWrite((100+i),HIGH);
-delay(500);
+ delay(500);
-digitalWrite((100+i),0);
+ digitalWrite((100+i),0);
-delay(500);
+ delay(500);
-−
+ }
-−
+ }
-−
+ }

@@ Line 30: / Line 30: @@
 ==Product Parameters==
-. Working voltage: 2.5V-6V
+*1. Working voltage: 2.5V-6V
-. IO voltage: 3.3V or 5.5
+*2. IO voltage: 3.3V or 5.5
-. Expand 8 Bidirectional IO
+*3. Expand 8 Bidirectional IO
-. I2C bus
+*4. I2C bus
-. 100 kHz I2C-bus interface (Standard-mode I2C-bus)
+*5. 100 kHz I2C-bus interface (Standard-mode I2C-bus)
-. −40°C to +85°C operation
+*6. −40°C to +85°C operation
 =Hardware=