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Working! with print formatting and everything!

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Eric Jiang 2011-02-13 21:53:57 -05:00
parent e48f9984c7
commit 89eede04c8
1 changed files with 137 additions and 26 deletions
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163
usbscale.c
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@ -1,21 +1,36 @@
#include <stdio.h>
#include <sys/types.h>
#include <stdint.h>
#include <math.h>
#include <libusb-1.0/libusb.h>
#include "scales.h"
#define DEBUG 1
//#define DEBUG
/*
* These constants are from libhid/include/constants.h
* and usage based on libhid/src/hid_exchange.c
* also vvvoutput.txt
*/
#define HID_REPORT_GET 0x01
#define HID_RT_INPUT 0x01
#define WEIGH_REPORT_ID 0x06 // Scale Data Report ID
#define WEIGH_REPORT_SIZE 0x06
static libusb_device* find_scale(libusb_device**);
static int print_scale_data(char*);
const char* UNITS[13] = {
"units", // unknown unit
"mg", // milligram
"g", // gram
"kg", // kilogram
"cd", // carat
"taels", // lian
"gr", // grain
"dwt", // pennyweight
"tonnes", // metric tons
"tons", // avoir ton
"ozt", // troy ounce
"oz", // ounce
"lbs" // pound
};
int main(void)
{
@ -50,29 +65,48 @@ int main(void)
#endif
libusb_claim_interface(handle, 0);
/*
* Try to transfer data about status
*
* http://www.beyondlogic.org/usbnutshell/usb6.shtml
* test_libhid.c
* http://rowsandcolumns.blogspot.com/2011/02/read-from-magtek-card-swipe-reader-in.html
*/
unsigned char data[WEIGH_REPORT_SIZE];
unsigned int len;
unsigned int res = libusb_interrupt_transfer(
handle,
//bmRequestType => direction: in, type: class,
// recipient: interface
LIBUSB_ENDPOINT_IN | //LIBUSB_REQUEST_TYPE_CLASS |
LIBUSB_RECIPIENT_INTERFACE,
data,
WEIGH_REPORT_SIZE, // length of data
&len,
10000 //timeout => 10 sec
);
int i;
printf("Got %d bytes from control transfer:\n", len);
for(i = 0; i < WEIGH_REPORT_SIZE; i++) {
printf("%x\n", data[i]);
unsigned int res;
int continue_reading = 0;
int scale_result = -1;
for(;;) {
res= libusb_interrupt_transfer(
handle,
//bmRequestType => direction: in, type: class,
// recipient: interface
LIBUSB_ENDPOINT_IN | //LIBUSB_REQUEST_TYPE_CLASS |
LIBUSB_RECIPIENT_INTERFACE,
data,
WEIGH_REPORT_SIZE, // length of data
&len,
10000 //timeout => 10 sec
);
if(res == 0) {
#ifdef DEBUG
int i;
for(i = 0; i < WEIGH_REPORT_SIZE; i++) {
printf("%x\n", data[i]);
}
#endif
scale_result = print_scale_data(data);
if(scale_result != 1)
break;
}
else {
fprintf(stderr, "Error in USB transfer\n");
scale_result = -1;
break;
}
}
@ -86,13 +120,87 @@ int main(void)
libusb_close(handle);
libusb_free_device_list(devs, 1);
libusb_exit(NULL);
return 0;
return scale_result;
}
//
// print_scale_data
// ----------------
//
// **print_scale_data** takes the 6 bytes of binary data sent by the scale and
// interprets and prints it out.
//
// **Returns:** `0` if weight data was successfully read, `1` if the data
// indicates that more data needs to be read (i.e. keep looping), and `-1` if
// the scale data indicates that some error occurred and that the program
// should terminate.
//
static int print_scale_data(char* dat) {
static uint8_t lastStatus = 0;
uint8_t report = dat[0];
uint8_t status = dat[1];
uint8_t unit = dat[2];
uint8_t expt = dat[3];
long weight = dat[4] + (dat[5] << 8);
if(expt != 255 && expt != 0) {
weight = pow(weight, expt);
}
if(report != 0x03) {
fprintf(stderr, "Error reading scale data\n");
return -1;
}
switch(status) {
case 0x01:
fprintf(stderr, "Scale reports Fault\n");
return -1;
case 0x02:
if(status != lastStatus)
fprintf(stderr, "Scale is zero'd...\n");
break;
case 0x03:
if(status != lastStatus)
fprintf(stderr, "Weighing...\n");
break;
case 0x04:
printf("%ld %s\n", weight, UNITS[unit]);
return 0;
case 0x05:
if(status != lastStatus)
fprintf(stderr, "Scale reports Under Zero\n");
break;
case 0x06:
if(status != lastStatus)
fprintf(stderr, "Scale reports Over Weight\n");
break;
case 0x07:
if(status != lastStatus)
fprintf(stderr, "Scale reports Calibration Needed\n");
break;
case 0x08:
if(status != lastStatus)
fprintf(stderr, "Scale reports Re-zeroing Needed!\n");
break;
default:
if(status != lastStatus)
fprintf(stderr, "Unknown status code: %d\n", status);
return -1;
}
lastStatus = status;
return 1;
}
static libusb_device* find_scale(libusb_device **devs)
{
if(DEBUG)
#ifdef DEBUG
libusb_set_debug(NULL, 3);
#endif
int i = 0;
libusb_device* dev;
@ -117,13 +225,15 @@ static libusb_device* find_scale(libusb_device **devs)
*/
#ifdef DEBUG
printf("Found scale %04x:%04x (bus %d, device %d)\n",
fprintf(stderr,
"Found scale %04x:%04x (bus %d, device %d)\n",
desc.idVendor,
desc.idProduct,
libusb_get_bus_number(dev),
libusb_get_device_address(dev));
printf("It has descriptors:\n\tmanufc: %d\n\tprodct: %d\n\tserial: %d\n\tclass: %d\n\tsubclass: %d\n",
fprintf(stderr,
"It has descriptors:\n\tmanufc: %d\n\tprodct: %d\n\tserial: %d\n\tclass: %d\n\tsubclass: %d\n",
desc.iManufacturer,
desc.iProduct,
desc.iSerialNumber,
@ -139,7 +249,8 @@ static libusb_device* find_scale(libusb_device **devs)
r = libusb_get_string_descriptor_ascii(hand, desc.iManufacturer,
string, 256);
printf("Manufacturer: %s\n", string);
fprintf(stderr,
"Manufacturer: %s\n", string);
libusb_close(hand);
#endif
return dev;