/Designs/Tools/i2c_AVR_USB/SW/testapp/PC/i2c_usb.c
0,0 → 1,438
/*
* i2c_usb.c - test application for the i2c-tiby-usb interface
* http://www.harbaum.org/till/i2c_tiny_usb
*
* $Id: i2c_usb.c,v 1.5 2007/01/05 19:30:43 harbaum Exp $
*/
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <usb.h>
 
/* ds1621 chip address (A0-A2 tied low) */
#define DS1621_ADDR 0x48
 
/* pcf8574 chip address (A0-A2 tied low) */
#define PCF8574_ADDR 0x20
 
#define LOOPS 100
 
#define USB_CTRL_IN (USB_TYPE_CLASS | USB_ENDPOINT_IN)
#define USB_CTRL_OUT (USB_TYPE_CLASS)
 
/* the vendor and product id was donated by ftdi ... many thanks!*/
#define I2C_TINY_USB_VID 0x0403
#define I2C_TINY_USB_PID 0xc631
 
#ifdef WIN
#include <windows.h>
#include <winbase.h>
#define usleep(t) Sleep((t) / 1000)
#endif
 
#define I2C_M_RD 0x01
 
/* commands via USB, must e.g. match command ids firmware */
#define CMD_ECHO 0
#define CMD_GET_FUNC 1
#define CMD_SET_DELAY 2
#define CMD_GET_STATUS 3
#define CMD_I2C_IO 4
#define CMD_I2C_BEGIN 1 // flag to I2C_IO
#define CMD_I2C_END 2 // flag to I2C_IO
 
#define STATUS_IDLE 0
#define STATUS_ADDRESS_ACK 1
#define STATUS_ADDRESS_NAK 2
 
usb_dev_handle *handle = NULL;
 
/* write a set of bytes to the i2c_tiny_usb device */
int i2c_tiny_usb_write(int request, int value, int index){
 
if(usb_control_msg(handle, USB_CTRL_OUT, request,
value, index, NULL, 0, 1000) < 0) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return -1;
}
return 1;
}
 
/* read a set of bytes from the i2c_tiny_usb device */
int i2c_tiny_usb_read(unsigned char cmd, void *data, int len) {
int nBytes;
 
/* send control request and accept return value */
nBytes = usb_control_msg(handle,USB_CTRL_IN, cmd, 0, 0, data, len, 1000);
 
if(nBytes < 0) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return nBytes;
}
 
return 0;
}
 
/* get i2c usb interface test */
void i2c_tiny_usb_test(void) {
unsigned long func;
if(i2c_tiny_usb_read(CMD_ECHO, &func, sizeof(func)) == 0)
printf("Functionality = %lx\n", func);
}
 
 
/* get i2c usb interface firmware version */
void i2c_tiny_usb_get_func(void) {
unsigned long func;
if(i2c_tiny_usb_read(CMD_GET_FUNC, &func, sizeof(func)) == 0)
printf("Functionality = %lx\n", func);
}
 
/* set a value in the I2C_USB interface */
void i2c_tiny_usb_set(unsigned char cmd, int value) {
if(usb_control_msg(handle,
USB_TYPE_VENDOR, cmd, value, 0,
NULL, 0, 1000) < 0) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
}
}
 
/* get the current transaction status from the i2c_tiny_usb interface */
int i2c_tiny_usb_get_status(void) {
int i;
unsigned char status;
if((i=i2c_tiny_usb_read(CMD_GET_STATUS, &status, sizeof(status))) < 0) {
fprintf(stderr, "Error reading status\n");
return i;
}
 
return status;
}
 
/* write command and read an 8 or 16 bit value from the given chip */
int i2c_read_with_cmd(unsigned char addr, char cmd, int length) {
unsigned char result[2];
 
if((length < 0) || (length > sizeof(result))) {
fprintf(stderr, "request exceeds %lu bytes\n", sizeof(result));
return -1;
}
 
/* write one byte register address to chip */
if(usb_control_msg(handle, USB_CTRL_OUT,
CMD_I2C_IO + CMD_I2C_BEGIN
+ ((!length)?CMD_I2C_END:0),
0, addr, &cmd, 1,
1000) < 1) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return -1;
}
 
if(i2c_tiny_usb_get_status() != STATUS_ADDRESS_ACK) {
fprintf(stderr, "write command status failed\n");
return -1;
}
 
// just a test? return ok
if(!length) return 0;
 
if(usb_control_msg(handle,
USB_CTRL_IN,
CMD_I2C_IO + CMD_I2C_END,
I2C_M_RD, addr, (char*)result, length,
1000) < 1) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return -1;
}
 
if(i2c_tiny_usb_get_status() != STATUS_ADDRESS_ACK) {
fprintf(stderr, "read data status failed\n");
return -1;
}
 
// return 16 bit result
if(length == 2)
return 256*result[0] + result[1];
 
// return 8 bit result
return result[0];
}
 
/* write a single byte to the i2c client */
int i2c_write_byte(unsigned char addr, char data) {
 
/* write one byte register address to chip */
if(usb_control_msg(handle, USB_CTRL_OUT,
CMD_I2C_IO + CMD_I2C_BEGIN + CMD_I2C_END,
0, addr, &data, 1,
1000) < 1) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return -1;
}
 
if(i2c_tiny_usb_get_status() != STATUS_ADDRESS_ACK) {
fprintf(stderr, "write command status failed\n");
return -1;
}
 
return 0;
}
 
/* write a command byte and a single byte to the i2c client */
int i2c_write_cmd_and_byte(unsigned char addr, char cmd, char data) {
char msg[2];
 
msg[0] = cmd;
msg[1] = data;
 
/* write one byte register address to chip */
if(usb_control_msg(handle, USB_CTRL_OUT,
CMD_I2C_IO + CMD_I2C_BEGIN + CMD_I2C_END,
0, addr, msg, 2,
1000) < 1) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return -1;
}
 
if(i2c_tiny_usb_get_status() != STATUS_ADDRESS_ACK) {
fprintf(stderr, "write command status failed\n");
return -1;
}
 
return 0;
}
 
/* write a command byte and a 16 bit value to the i2c client */
int i2c_write_cmd_and_word(unsigned char addr, char cmd, int data) {
char msg[3];
 
msg[0] = cmd;
msg[1] = data >> 8;
msg[2] = data & 0xff;
 
/* write one byte register address to chip */
if(usb_control_msg(handle, USB_CTRL_OUT,
CMD_I2C_IO + CMD_I2C_BEGIN + CMD_I2C_END,
0, addr, msg, 3,
1000) < 1) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
return -1;
}
 
if(i2c_tiny_usb_get_status() != STATUS_ADDRESS_ACK) {
fprintf(stderr, "write command status failed\n");
return -1;
}
 
return 0;
}
 
/* read ds1621 control register */
void ds1621_read_control(void) {
int result;
 
do {
result = i2c_read_with_cmd(DS1621_ADDR, 0xac, 1);
} while(!(result & 0x80));
}
 
 
 
/* main program process */
 
 
int main(int argc, char *argv[]) {
struct usb_bus *bus;
struct usb_device *dev;
int i;
#ifndef WIN
int ret;
#endif
printf("-- i2c-tiny-usb test application --\n");
printf("-- (c) 2006 by Till Harbaum --\n");
printf("-- http://www.harbaum.org/till/i2c_tiny_usb --\n");
 
usb_init();
usb_find_busses();
usb_find_devices();
for(bus = usb_get_busses(); bus; bus = bus->next) {
for(dev = bus->devices; dev; dev = dev->next) {
if((dev->descriptor.idVendor == I2C_TINY_USB_VID) &&
(dev->descriptor.idProduct == I2C_TINY_USB_PID)) {
printf("Found i2c_tiny_usb device on bus %s device %s.\n",
bus->dirname, dev->filename);
/* open device */
if(!(handle = usb_open(dev)))
fprintf(stderr, "Error: Cannot open the device: %s\n",
usb_strerror());
 
break;
}
}
}
if(!handle) {
fprintf(stderr, "Error: Could not find i2c_tiny_usb device\n");
 
#ifdef WIN
printf("Press return to quit\n");
getchar();
#endif
 
exit(-1);
}
 
#ifndef WIN
/* Get exclusive access to interface 0. Does not work under windows. */
ret = usb_claim_interface(handle, 0);
if (ret != 0) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
 
exit(1);
}
#endif
 
printf("writing to adapter");
i2c_tiny_usb_write(0,0,0);
 
/* do some testing */
printf("Getting adapter functionalities");
i2c_tiny_usb_get_func();
 
/* try to set i2c clock to 100kHz (10us), will actually result in ~50kHz */
/* since the software generated i2c clock isn't too exact. in fact setting */
/* it to 10us doesn't do anything at all since this already is the default */
printf("Reseting I2C clock to 100 kHz");
i2c_tiny_usb_set(CMD_SET_DELAY, 10);
 
/* -------- begin of ds1621 client processing --------- */
printf("Probing for DS1621 ... ");
 
/* try to access ds1621 at address DS1621_ADDR */
if(usb_control_msg(handle, USB_CTRL_IN,
CMD_I2C_IO + CMD_I2C_BEGIN + CMD_I2C_END,
0, DS1621_ADDR, NULL, 0,
1000) < 0) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
goto quit;
}
if(i2c_tiny_usb_get_status() == STATUS_ADDRESS_ACK) {
int temp;
 
printf("success at address 0x%02x\n", DS1621_ADDR);
 
/* activate one shot mode */
if(i2c_write_cmd_and_byte(DS1621_ADDR, 0xac, 0x01) < 0)
goto quit;
 
/* wait 10ms */
usleep(10000);
 
#if 0
/* write default limits */
/* high threshold: +15 deg celsius */
i2c_write_cmd_and_word(DS1621_ADDR, 0xa1, 0x0f00); /* 15 deg celsius */
usleep(10000);
/* low threshold: +10 deg celsius */
i2c_write_cmd_and_word(DS1621_ADDR, 0xa2, 0x0a00);
usleep(10000);
#endif
/* display limits */
temp = i2c_read_with_cmd(DS1621_ADDR, 0xa1, 2);
printf("high temperature threshold = %d.%03d\n",
temp>>8, 1000 * (temp & 0xff) / 256);
temp = i2c_read_with_cmd(DS1621_ADDR, 0xa2, 2);
printf("low temperature threshold = %d.%03d\n",
temp>>8, 1000 * (temp & 0xff) / 256);
printf("Getting %d temperature readings:\n", LOOPS);
for(i=0;i<LOOPS;i++) {
int temp;
int counter, slope;
/* just write command 0xee to start conversion */
if(i2c_read_with_cmd(DS1621_ADDR, 0xee, 0) < 0)
goto quit;
ds1621_read_control();
temp = i2c_read_with_cmd(DS1621_ADDR, 0xaa, 2);
if(temp < 0)
goto quit;
/* read counter and slope values */
counter = i2c_read_with_cmd(DS1621_ADDR, 0xa8, 1);
slope = i2c_read_with_cmd(DS1621_ADDR, 0xa9, 1);
/* use counter and slope to adjust temperature (see ds1621 datasheet) */
temp = (temp & 0xff00) - 256/4;
temp += 256 * (slope - counter) / slope;
printf("temp = %d.%03d\n", temp>>8, 1000 * (temp & 0xff) / 256);
}
} else
printf("failed\n");
/* -------- end of ds1621 client processing --------- */
 
/* -------- begin of pcf8574 client processing --------- */
printf("Probing for PCF8574 ... ");
 
/* try to access pcf8574 at address PCF8574_ADDR */
if(usb_control_msg(handle, USB_CTRL_IN,
CMD_I2C_IO + CMD_I2C_BEGIN + CMD_I2C_END,
0, PCF8574_ADDR, NULL, 0,
1000) < 0) {
fprintf(stderr, "USB error: %s\n", usb_strerror());
goto quit;
}
if(i2c_tiny_usb_get_status() == STATUS_ADDRESS_ACK) {
unsigned char bit_mask = 0xfe;
 
printf("success at address 0x%02x\n", PCF8574_ADDR);
 
printf("Cycling 0 bit %d times.\n", LOOPS);
/* just rotate a single 0 bit through the outputs */
 
for(i=0;i<LOOPS;i++) {
if(i2c_write_byte(PCF8574_ADDR, bit_mask) < 0)
goto quit;
/* rotate the byte */
bit_mask = (bit_mask << 1) | 1;
if(bit_mask == 0xff)
bit_mask = 0xfe;
 
usleep(100000);
}
} else
printf("failed\n");
/* -------- end of pcf8574 client processing --------- */
 
quit:
#ifndef WIN
ret = usb_release_interface(handle, 0);
if (ret)
fprintf(stderr, "USB error: %s\n", usb_strerror());
#endif
 
usb_close(handle);
 
#ifdef WIN
printf("Press return to quit\n");
getchar();
#endif
 
return 0;
}