TI TCA9539
16-bit 1.65- to 5.5-V I2C/SMBus I/O expander with interrupt, reset & config registers
IO-EXPANDER-EVM: I2C and SMBus IO Expander Evaluation Module
1. 修改 /boot/config.txt 內容
intf:i2c6=on /* 原始前面有個 # 要去除, 把 off 改為on */
2. 連接 I2C
SCL: IO-EXPANDER J8 SCL
SDA: IO-EXPANDER J8 SDA
GND: IO-EXPANDER J7 GND
VCC: IO-EXPANDER J9 VCC
3.Device Address
PS: IO Expander EVM User's Guide (Rev. A) 這一片是共用PCB.
TCA6424A 0100010 0x22
TCA9539 1110111 0x77
GPIO設定, 主要是在Registers 6 和7
但這片 IO Expander EVM 另外拉了幾條線用於顯示LED燈
可以直接改用J13 來測試GPIO
i2cmsg.addr = nDevAddr;
第二個是 Registers 6或7
第三個就是 GPIO Pin 0到N 的 GPIO ON/OFF
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <err.h>
#include <errno.h>
#include <string.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#define DEFAULT_I2C_BUS "/dev/i2c-6"
// 0100010 0x22 TCA6424A
// 1110111 0x77 TCA9539
#define DEFAULT_TCA9539_ADDR 0x77
int TCA9539_write( int nFile, unsigned int nDevAddr, unsigned int nRegConfig,
unsigned char *pBuf, unsigned char nLen)
{
struct i2c_rdwr_ioctl_data msg_rdwr;
struct i2c_msg i2cmsg;
int nRecLen;
unsigned char sI2cBuf[0xFF];
unsigned char *pI2cBuf = &sI2cBuf[0];
msg_rdwr.msgs = &i2cmsg;
msg_rdwr.nmsgs = 1;
pI2cBuf[0] = (unsigned char)nRegConfig;
pI2cBuf[1] = pBuf[0];
i2cmsg.addr = nDevAddr;
i2cmsg.flags = 0; // Write
i2cmsg.len = 2;
i2cmsg.buf = pI2cBuf;
if( ( nRecLen = ioctl( nFile, I2C_RDWR, &msg_rdwr)) < 0)
{
perror("W5A-ioctl()");
fprintf( stderr,"W5B-ioctl %d\n%s\n", nRecLen, strerror(errno));
return -1;
}
else
return nRecLen;
}
int TCA9539_read( int nFile, unsigned int nDevAddr, unsigned int nRegConfig,
unsigned char *pBuf, unsigned char nLen)
{
struct i2c_rdwr_ioctl_data msg_rdwr;
struct i2c_msg i2cmsg[2];
unsigned char sAdsBuf[3];
unsigned char *pAdsBuf = &sAdsBuf[0];
int nRecLen;
msg_rdwr.msgs = i2cmsg;
msg_rdwr.nmsgs = 2;
pAdsBuf[0] = (unsigned char)nRegConfig;
i2cmsg[0].addr = nDevAddr;
i2cmsg[0].flags = 0; // Write
i2cmsg[0].len = 1;
i2cmsg[0].buf = pAdsBuf;
i2cmsg[1].addr = nDevAddr;
i2cmsg[1].flags = I2C_M_RD; // read data, from slave to master
i2cmsg[1].len = nLen;
i2cmsg[1].buf = pBuf;
if( ( nRecLen = ioctl( nFile, I2C_RDWR, &msg_rdwr))<0)
{
perror("R5-TCA9539_read ioctl failed");
fprintf(stderr,"R6-TCA9539_read ioctl returned %d\n", nRecLen);
return -1;
}
else
{
return nRecLen;
}
}
int main(void)
{
int nDevAddr = DEFAULT_TCA9539_ADDR;
int nFile, nWriteLen, nReadLen, nRecLen;
int nRc, nRegConfig;
const char *pDevice = DEFAULT_I2C_BUS; //"/dev/i2c-6";
unsigned char sBuf[0x10], sStrBuf[0x10];
unsigned char *pBuf= &sBuf[0];
unsigned long nFuncs;
printf("Hello! This is a test prgoram.\n");
nFile = open( pDevice, O_RDWR);
if( nFile < 0)
err( errno, "O1-Tried to open '%s'", pDevice);
else
printf( "\nO2-Open dev i2c-6 success.\n");
if( ioctl( nFile, I2C_FUNCS, &nFuncs) < 0)
{
perror("W5A-ioctl()");
fprintf(stderr, "Error: Could not get the adapter functionality matrix: %s\n",
strerror(errno));
close( nFile);
exit(0);
}
ioctl( nFile, I2C_TIMEOUT,2); // TIMEOUT
ioctl( nFile, I2C_RETRIES,1); // retry count
nRc = ioctl( nFile, I2C_SLAVE, nDevAddr);
if( nRc < 0)
{
err(errno, "O3-Tried to set device address '0x%02x'", nDevAddr);
exit(0);
}
else
{
printf("O4-Dev i2c-6 Set Address 0x50 success.\n");
}
// https://www.ti.com/product/zh-tw/TCA9539 // Pull High
// Table 7. Registers 6 And 7 (Configuration Registers)
nDevAddr = DEFAULT_TCA9539_ADDR;
nRegConfig = 0x06; // Registers 6 Configuration
pBuf[0] = 0x00; // Set GPIO Pin-0 to Pin-7 all Pull Low
nWriteLen = 1;
nRecLen = TCA9539_write( nFile, nDevAddr, nRegConfig, pBuf, nWriteLen);
if( nRecLen < 0)
{
printf( "W3A-TCA9539_write failed.\n");
exit(0);
}
else
{
fprintf( stderr, "W6-Set gpio pin0-7: 0x%02x\n", pBuf[0]);
}
nRegConfig = 0x07; // Registers 7 Configuration
pBuf[0] = 0x00; // Set GPIO Pin-10 to Pin-17 all Pull Low
nWriteLen = 1;
nRecLen = TCA9539_write( nFile, nDevAddr, nRegConfig, pBuf, nWriteLen);
if( nRecLen < 0)
{
printf( "W3A-TCA9539_write failed.\n");
exit(0);
}
else
{
fprintf( stderr, "W7-Set gpio pin10-17: 0x%02x\n", pBuf[0]);
}
// Read Process
nDevAddr = DEFAULT_TCA9539_ADDR;
nRegConfig = 0x06; // Registers 6 Configuration
pBuf[0] = 0xFF; // Read GPIO Pin-0 to Pin-7
nReadLen = 1;
nRecLen = TCA9539_read( nFile, nDevAddr, nRegConfig, pBuf, nReadLen);
if( nRecLen < 0)
{
printf("R1-TCA9539_read failed.\n");
exit(1);
}
else
{
fprintf( stderr, "W6-Get gpio pin0-7: 0x%02x\n", pBuf[0]);
}
nRegConfig = 0x07; // Registers 7 Configuration
pBuf[0] = 0xFF; // Read GPIO Pin-10 to Pin-17
nReadLen = 1;
nRecLen = TCA9539_read( nFile, nDevAddr, nRegConfig, pBuf, nReadLen);
if( nRecLen < 0)
{
printf("R1-TCA9539_read failed.\n");
exit(1);
}
else
{
fprintf( stderr, "W6-Get gpio pin10-17: 0x%02x\n", pBuf[0]);
}
close( nFile);
return 0;
}
5.
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