skylarmt/usbscale
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Compiles and runs... but no data?

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This commit is contained in:
Eric Jiang 2011-01-29 23:49:38 -05:00
parent cc1d6950b3
commit 7b4cde73b0
1 changed files with 102 additions and 36 deletions
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126
usbscale.c
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@ -6,15 +6,91 @@
#define DEBUG 1
static void print_devs(libusb_device **devs)
static libusb_device* find_scale(libusb_device**);
int main(void)
{
libusb_device **devs;
int r;
ssize_t cnt;
libusb_device* dev;
libusb_device_handle* handle;
r = libusb_init(NULL);
if (r < 0)
return r;
/*
* Get a list of USB devices
*/
cnt = libusb_get_device_list(NULL, &devs);
if (cnt < 0)
return (int) cnt;
/*
* Look for a scale amongst the USB devices
*/
dev = find_scale(devs);
/*
* Open a handle to this found scale
*/
libusb_open(dev, &handle);
#ifdef __linux__
libusb_detach_kernel_driver(handle, 0);
#endif
libusb_claim_interface(handle, 0);
/*
* Try to transfer data about status
*
* http://www.beyondlogic.org/usbnutshell/usb6.shtml
*/
unsigned char blah[8];
libusb_control_transfer(
handle,
LIBUSB_ENDPOINT_IN | LIBUSB_REQUEST_TYPE_CLASS |
LIBUSB_RECIPIENT_INTERFACE,
//bmRequestType => direction: in, type: class,
// recipient: interface
0x01, //bRequest => HID get report
0x0300, //wValue => feature report
0x00, //windex => interface 0
blah,
8, //wLength
1000 //timeout => 1 sec
);
int i;
for(i = 0; i < 8; i++) {
printf("%x\n", blah[i]);
}
/*
* Free the device handle, device list and other cleanup
* tasks
*/
#ifdef __linux__
libusb_attach_kernel_driver(handle, 0);
#endif
libusb_close(handle);
libusb_free_device_list(devs, 1);
libusb_exit(NULL);
return 0;
}
static libusb_device* find_scale(libusb_device **devs)
{
if(DEBUG)
libusb_set_debug(null, 3);
libusb_set_debug(NULL, 3);
libusb_device *dev;
int i = 0;
libusb_device* dev;
/*
* Loop through each usb device, and for each device, loop through the
* scales list to see if it's one of our listed scales
*/
while ((dev = devs[i++]) != NULL) {
struct libusb_device_descriptor desc;
int r = libusb_get_device_descriptor(dev, &desc);
@ -26,49 +102,39 @@ static void print_devs(libusb_device **devs)
for (i = 0; i < scalesc; i++) {
if(desc.idVendor == scales[i][0] &&
desc.idProduct == scales[i][1]) {
if(DEBUG) {
/*
* Debugging data about found scale
*/
#ifdef DEBUG
printf("Found scale %04x:%04x (bus %d, device %d)\n",
desc.idVendor, desc.idProduct,
libusb_get_bus_number(dev), libusb_get_device_address(dev));
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",
desc.iManufacturer,
desc.iProduct,
desc.iSerialNumber);
}
/*
* A char buffer to pull string descriptors in from the device
*/
unsigned char string[256];
libusb_device_handle* hand;
libusb_open(dev, &hand);
r = libusb_get_string_descriptor_ascii(hand, desc.iManufacturer,
string, 256);
printf("Manufacturer: %s\n", string);
libusb_close(hand);
#endif
return dev;
break;
}
}
}
}
int main(void)
{
libusb_device **devs;
int r;
ssize_t cnt;
r = libusb_init(NULL);
if (r < 0)
return r;
cnt = libusb_get_device_list(NULL, &devs);
if (cnt < 0)
return (int) cnt;
print_devs(devs);
libusb_free_device_list(devs, 1);
libusb_exit(NULL);
return 0;
}