NXP PCA9532

The PCA9532 is a 16-bit I2C-bus and SMBus I/O expander optimized for dimming LEDs in 256 discrete steps for Red/Green/Blue (RGB) color mixing and back light applications. The driver is implemented in source files pca9532.c/.h and provides communications support with the device over an I²C bus.

Device Information

• http://www.nxp.com/documents/data_sheet/PCA9532.pdf

Basic Usage

The code snippet below shows how to create an instance of the driver and establish communications with the device.

#include "Drivers/NXP/pca9532.h"
#include <assert.h>

static I2C i2c;                             /* Allocate an I2C port for communicating with the device */
static PCA9532 driver;                      /* Allocate an instance of the driver */

void APP_Example(void)
{
    STATUS status;


    status = I2C_Open(&i2c,                 /* Open the I2C port */
                      0,                    /* Port number (0) */
                      400000);              /* Clock rate (400khz) */

    assert(status == SUCCESS);

    status = PCA9532_Open(&driver,          /* Open the driver */
                          &i2c,             /* Provide the I2C port to be used by the driver */
                          0);               /* The bottom address value (A0-A2 on board) */

    assert(status == SUCCESS);
}

The snippet below shows how to read and write the pin values to the device.

PCA9532_ReadPins(&driver, &pins);               /* Read the current state of the pins on the device */
PCA9532_WritePins(&driver, 0);                  /* Write all pins to high-impedance (LED off) */

/* When writing the pin values, each pin state
is represented by 2-bits (thus the values below) */

PCA9532_WritePins(&driver, 0x55555555);         /* Write all pins to low (LED on) */
PCA9532_WritePins(&driver, 0xAAAAAAAA);         /* Write all pins to blink at PWM0 rate */
PCA9532_WritePins(&driver, 0xFFFFFFFF);         /* Write all pins to blink at PWM1 rate */

Examples

The demo projects for the following boards provide an example of the usage of this driver.

• NXP LPC1769 - LED Demo Project