The PCAL9555, PCAL9554 series is a low-voltage 16-bit/8-bit General Purpose Input/Output (GPIO) expander with interrupt. This conponent library is compatible to basic operation os GPIO expanders: PCAL9555, PCA9555, PCA9535, PCA9539, PCAL9554, PCA9554 and PCA9538. On addition to this, this library is including mbed-SDK-style APIs. APIs that similar to DigitaiInOut, DigitalOut, DigitalIn, BusInOUt, BusOut and BusIn are available.
Dependents: PCAL9555_Hello OM13082-JoyStick OM13082_LED OM13082-test ... more
What is this?
This conponent library is compatible to basic operation os GPIO expanders: PCAL9555, PCA9555, PCA9535, PCA9539, PCAL9554, PCA9554 and PCA9538 .
On addition to this, this library is including mbed-SDK-style APIs. APIs that similar to DigitaiInOut
, DigitalOut
, DigitalIn
, BusInOut
, BusOut
and BusIn
are available.
How to use?
Wiring
Wiring between mbed and 16-bit GPIO expander
Wiring between mbed and 8-bit GPIO expander
Very basic register level I/O bit operation
PCAL9555 and PCAL9554 are class libraries for those compatible GPIO expander chips.
Those class libraries provides interface for bit operation of its I/O port.
For 16-bit GPIO expanders, the input/output access and its direction setting can be done by 16-bit data. For 8-bit GPIO expanders, those can be done by 8-bit data.
#include "mbed.h" #include "PCAL9555.h" PCAL9555 gpio( p28, p27, 0xE8 ); // using PCA9539 int main() { gpio.configure( 0xFFFF ); // Set all pins: input printf( " 0x%04X\r\n", (int)gpio );// Print pins state gpio.configure( 0x0000 ); // Set all pins: output int count = 0; while(1) { gpio.write( count++ ); } }
High level APIs
To use the GPIO expanders more simple, this library is including mbed-SDK-style APIs.
APIs that similar to DigitaiInOut
, DigitalOut
, DigitalIn
, BusInOut
, BusOut
and BusIn
are available.
GpioDigitalOut, GpioDigitaiInOut, GpioDigitalIn
Next code shows sample of DigitalOut
equivalent API GpioDigitalOut
usage.
A pin on the PCAL9555 is defined as pin and its state is changed by assignment.
(For single pin operation, GpioDigitaiInOut
and GpioDigitalIn
are available also.)
#include "mbed.h" #include "PCAL9555.h" PCAL9555 gpio_exp( p28, p27, 0xE8 ); // SDA, SCL, Slave_address(option) GpioDigitalOut pin( gpio_exp, X0_0 ); int main() { while( 1 ) { pin = 1; wait( 0.2 ); pin = 0; wait( 0.2 ); } }
GpioBusOut, GpioBusInOut, GpioBusIn
BusOut
equivalent API GpioBusOut
is available too.
In next code, pins are grouped as mypins to manage the output as bus output.
(Same as GpioDigitalInOut and GpioDigitalIn APIs, GpioBusInOut
and GpioBusIn
are available also.)
#include "mbed.h" #include "PCAL9555.h" PCAL9555 gpio_exp( p28, p27, 0xE8 ); // SDA, SCL, Slave_address(option) GpioBusOut mypins( gpio_exp, X0_0, X0_1, X0_2, X0_3 ); int main() { while( 1 ) { for( int i = 0; i < 16; i++ ) { mypins = i; wait( 0.25 ); } } }
The high level APIs can be used in combination
Those high level APIs can be used in combination.
Each pins can be managed by instances.
#include "mbed.h" #include "PCAL9555.h" PCAL9555 gpio( p28, p27, 0xE8 ); // using PCA9539 // The GPIO pins are grouped in some groups and operated as bus I/O GpioBusIn bus_in( gpio, X0_0, X0_1, X0_2, X0_3 ); GpioBusOut bus_out( gpio, X0_4, X0_5, X0_6 ); GpioBusInOut bus_io( gpio, X1_7, X1_6, X1_5, X1_4, X1_3, X1_2, X1_1, X1_0 ); GpioDigitalOut myled( gpio, X0_7 ); int main() { bus_io.input(); printf( "I/O = 0x%02X\r\n", (int)bus_io ); printf( "In = 0x%01X\r\n", (int)bus_in ); bus_io.output(); int count = 0; while(1) { bus_out = count; bus_io = count; myled = count & 0x1; count++; wait( 0.1 ); } }
Diff: base_classes/CompGpioExp/GpioBus/GpioBusOut.h
- Revision:
- 0:6c9a51a50eea
- Child:
- 1:fd7cfa821b6a
diff -r 000000000000 -r 6c9a51a50eea base_classes/CompGpioExp/GpioBus/GpioBusOut.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/base_classes/CompGpioExp/GpioBus/GpioBusOut.h Sat Mar 07 12:56:05 2015 +0000 @@ -0,0 +1,76 @@ +/** GpioBusOut API for GPIO-expander component class + * + * @author Akifumi (Tedd) OKANO, NXP Semiconductors + * @version 0.5 + * @date 07-Mar-2015 + * + * Released under the Apache 2 license + */ + +#ifndef MBED_GpioBusOut +#define MBED_GpioBusOut + +#include "mbed.h" +#include "GpioBusInOut.h" + +/** GpioBusOut class + * + * @class GpioBusOut + * + * "GpioBusOut" class works like "BusOut" class of mbed-SDK. + * This class provides pin oriented API, abstracting the GPIO-expander chip. + * + * Example: + * @code + * #include "mbed.h" + * #include "PCAL9555.h" + * + * PCAL9555 gpio_exp( p28, p27, 0xE8 ); // SDA, SCL, Slave_address(option) + * GpioBusOut mypins( gpio_exp, X0_0, X0_1, X0_2, X0_3 ); + * + * int main() { + * while( 1 ) { + * for( int i = 0; i < 16; i++ ) { + * mypins = i; + * wait( 0.25 ); + * } + * } + * } + * @endcode + */ +class GpioBusOut : public GpioBusInOut +{ +public: + + /** Create an GpioBusOut, connected to the specified pins + * + * @param gpiop Instance of GPIO expander device + * @param p<n> DigitalInOut pin to connect to bus bit p<n> (GpioPinName) + * + * @note + * It is only required to specify as many pin variables as is required + * for the bus; the rest will default to NC (not connected) + */ + GpioBusOut( CompGpioExp &gpiop, + GpioPinName p0, GpioPinName p1 = X_NC, GpioPinName p2 = X_NC, GpioPinName p3 = X_NC, + GpioPinName p4 = X_NC, GpioPinName p5 = X_NC, GpioPinName p6 = X_NC, GpioPinName p7 = X_NC, + GpioPinName p8 = X_NC, GpioPinName p9 = X_NC, GpioPinName p10 = X_NC, GpioPinName p11 = X_NC, + GpioPinName p12 = X_NC, GpioPinName p13 = X_NC, GpioPinName p14 = X_NC, GpioPinName p15 = X_NC ); + GpioBusOut( CompGpioExp &gpiop, GpioPinName pins[ 16 ] ); + + /** + * Destractor + */ + virtual ~GpioBusOut(); + + /** A shorthand for write() + */ + GpioBusOut& operator= ( int rhs ); + GpioBusOut& operator= ( GpioBusOut& rhs ); + +private: + void init( void ); +} +; + +#endif // MBED_GpioBusOut