Sanchayan Maity
f815cdce4b
Preliminary commit with the following projects in Eclipse 1. gtkmm Hello World 2. PCF8574 I2C GPIO Expander 3. PCF8591 I2C A-D & D-A Converter 4. SPI based OLED Display with SSD1306 controller Library Dependencies 1. Gtk 2. Gtkmm 3. libsoc TODO: Documentation and cleanup
69 lines
1.3 KiB
C
69 lines
1.3 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <fcntl.h>
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#include <sys/ioctl.h>
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#include <linux/i2c-dev.h>
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#define PCF8591_ADDRESS 0x48
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int main( int argc, char **argv )
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{
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uint8_t i;
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uint32_t fd;
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uint32_t ret;
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uint8_t command[2];
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uint8_t value[4];
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useconds_t delay = 2000;
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char *dev = "/dev/i2c-0";
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printf("PCF8591 ADC and DAC test code\n");
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fd = open(dev, O_RDWR);
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if(fd < 0) {
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perror("Opening i2c device node\n");
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return 1;
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}
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ret = ioctl(fd, I2C_SLAVE, PCF8591_ADDRESS);
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if(ret < 0) {
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perror("Selecting i2c device\n");
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}
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while (true) {
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for(i = 0; i < 4; i++) {
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/*
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* Analog output enable | Read Input i
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* See Page 6 of NXP PCF8591 data sheet
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*/
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command[0] = 0x40 | ((i + 1) & 0x03); /* Control Byte */
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command[1]++; /* DAC Data Register */
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ret = write(fd, &command, 2);
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if (ret != 2)
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perror("writing i2c device");
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usleep(delay);
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/* the read is always one step behind the selected input */
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ret = read(fd, &value[i], 1);
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if(ret != 1)
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perror("reading i2c device");
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usleep(delay);
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}
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printf("0x%02x 0x%02x 0x%02x 0x%02x\n", value[0], value[1], value[2], value[3]);
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sleep(1);
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}
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close(fd);
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return(0);
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}
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