armfunc.c

#include "armfunc.h"
#include <stdio.h>
#include <sys/types.h>

#include <libusb.h>
#include <stdlib.h>

libusb_device **devs;
libusb_device_handle * devh;

int libraryInit()
{
    int r;
    ssize_t cnt;
    r = libusb_init(NULL); // must be called fir st before any other libusb function
    if (r < 0)
        return r;//failed to initialise

    cnt = libusb_get_device_list(NULL, &devs);//get a list of all usb devices on the system place it into the collection struct libusb_device
    if (cnt < 0)//cnt number of returned devices
        return (int) cnt;

    //open device directly with vid and pid
    //devh = libusb_open_device_with_vid_pid(NULL,vid,pid);
    int i;
    for(i = 0; i < cnt; i++) {
        libusb_device * device = devs[i];
        if(isRobotArm(device)) {
            int er = libusb_open(device,&devh);
            if(er < 0) {
                printf("Could Not Open Device: %s\n",libusb_error_name(er));
                return -1;
            }
        }
    }

    if(devh == NULL) {
        printf("Could not open Device\n");
        return -1;
    }

    libusb_free_device_list(devs, 1);//free device list

    //is there a kernel driver active
    if(libusb_kernel_driver_active(devh,0) == 1) {
        printf("Warning: kernel driver active attempting to detatch\n");
        if(libusb_detach_kernel_driver(devh,0) == 0) {
            printf("kernel driver Detatched continueing ..\n");
        } else {
            printf("ERROR: Failed to detatch kernel driver!\n");
            return -1;
        }

    }
    int rtnCode = libusb_claim_interface(devh,0);
    if(rtnCode < 0) {
        printf("Failure: Could Not claim interface\n");
    }
    printf("Interface claimed\n");
    printf("Robot arm Initialised ready for io ops\n");


}

int libraryDispose()
{

    //memory clean up
    printf("Cleaning up memory\n");
    int rd = libusb_release_interface(devh,0);

    if(rd < 0) {
        printf("Warning: Something horrible has happened ... cannot release interface\n");
        return -1;
    }

    libusb_close(devh);

    libusb_exit(NULL);//must be called when program quits

}



int isRobotArm(libusb_device * device){
  struct libusb_device_descriptor desc;
  libusb_get_device_descriptor(device,&desc);
  if(desc.idProduct == pid && desc.idVendor == vid){
    return 1;
  }
  return 0;

}

void msgToData(unsigned char* data, Message msg)
{
  
  data[0] = msg.b1;
  data[1] = msg.b2;
  data[2] = msg.b3;
  

}


 void printRobotInfo(libusb_device **devs){
  	libusb_device *dev;
	int i = 0;

	while ((dev = devs[i++]) != NULL) {
		struct libusb_device_descriptor desc;
		int r = libusb_get_device_descriptor(dev, &desc);
		if (r < 0) {
			fprintf(stderr, "failed to get device descriptor");
			return;
		}

        if((desc.idVendor == vid )&& (desc.idProduct == pid)) {
	  struct libusb_config_descriptor * config;
	  libusb_get_config_descriptor(dev,0,&config);
	  struct libusb_interface  interface =  config->interface[0];
	  struct libusb_interface_descriptor idesc = *interface.altsetting;


            printf("Found Robot Arm Device!\n");
	    printf("Vendor id: %d\n",desc.idVendor);
	    printf("Product id: %d\n",desc.idProduct);
	    printf("Device Class: %d\n",desc.bDeviceClass);
	    printf("Number of Interfaces: %d\n",config->bNumInterfaces);
	    printf("Number of end points: %d\n",idesc.bNumEndpoints);
	    printf("End point address: %d\n",idesc.endpoint->bEndpointAddress);
	    printf("End point descriptor type %d\n",idesc.endpoint->bDescriptorType);

	    libusb_free_config_descriptor(config);
        }

		printf("%04x:%04x (bus %d, device %d)\n",
			desc.idVendor, desc.idProduct,
			libusb_get_bus_number(dev), libusb_get_device_address(dev));
	}
}

 void print_devs(libusb_device **devs)
{
	libusb_device *dev;
	int i = 0;

	while ((dev = devs[i++]) != NULL) {
		struct libusb_device_descriptor desc;
		int r = libusb_get_device_descriptor(dev, &desc);
		if (r < 0) {
			fprintf(stderr, "failed to get device descriptor");
			return;
		}

		printf("%04x:%04x (bus %d, device %d)\n",
			desc.idVendor, desc.idProduct,
			libusb_get_bus_number(dev), libusb_get_device_address(dev));
	}
}