Thread: C++ libusb usb_control_msg problem

Hello Folks,

I Try to create my own program that can control a USB missile launcher. I try to accomplish this with the libusb library.

now i have a problem: I try to make my USB missile launcher move with the usb_control_msg function. know i got the problem that it does nothing, but give me a succesfull return value.

Extra info:

set active config: yes.
set active alternate interface: yes.
claimed a interface: yes.
opened a device: yes.

this is my code:

Code:

#include <usb.h>
#include <iostream>
#include <string.h>

#define STOP 	0
#define LEFT 	1
#define RIGHT 	2
#define UP 		4
#define DOWN 	8
#define FIRE 	16

usb_dev_handle *locate_misslelauncher(void);

using namespace std;

int main()
{
	struct usb_dev_handle *misslelauncher_handle;

	usb_init();
	usb_set_debug(2);

	if((misslelauncher_handle = locate_misslelauncher()) == 0)
	{
		cout << "kan device niet openen!" << endl;
	}
	else
	{
		cout << "device geopend!" << endl;

		char msg = 0x00;
		int cmd = msg |= FIRE;
		int result = 0;


	    int a = cmd & LEFT ? 1 : 0;
	    int b = cmd & RIGHT ? 1 : 0;
	    int c = cmd & UP ? 1 : 0;
	    int d = cmd & DOWN ? 1 : 0;
	    int e = cmd & FIRE ? 1 : 0;

	    cout << "a is:\t" << a << endl;
	    cout << "b is:\t" << b << endl;
	    cout << "c is:\t" << c << endl;
	    cout << "d is:\t" << d << endl;
	    cout << "e is:\t" << e << endl;


	   //result = usb_sendcommand(misslelauncher_handle, 0, a, b, c, d, e, 8, 8);

		unsigned char buffer[64];
		memset(buffer,0,64);

		  buffer[0] = a;
		  buffer[1] = b;
		  buffer[2] = c;
		  buffer[3] = d;
		  buffer[4] = e;
		  buffer[5] = 0;
		  buffer[6] = 8;
		  buffer[7] = 8;

	   result = usb_control_msg(misslelauncher_handle, 0x21,9,0x2, 0x0, (char*) buffer, 64,100);


	   cout << " result is:\t" << result << endl;
	}

	usb_release_interface(misslelauncher_handle,0);
	usb_close(misslelauncher_handle);
	return 0;
}

usb_dev_handle *locate_misslelauncher(void)
{
	unsigned int vendorid = 4400;
	unsigned int productid = 514;
	unsigned int located = 0;

	struct usb_bus *bus;
	struct usb_device *device;
	usb_dev_handle *devicehandle = 0;

	usb_find_busses();
	usb_find_devices();

	for(bus = usb_busses;bus;bus = bus->next)
	{
		for(device = bus->devices;device; device = device->next)
		{
			if(device->descriptor.idVendor == vendorid && device->descriptor.idProduct == productid)
			{
				located++;
				devicehandle = usb_open(device);

				int config = 0;

				for(int c = 0; c < device->descriptor.bNumConfigurations; c++)
				{
					config = c;
					for(int i = 0; i < device->config[config].bNumInterfaces; i++)
					{
						usb_detach_kernel_driver_np(devicehandle, i);
					}
				}

				int setconfigstatus = usb_set_configuration(devicehandle, device->config[config].bConfigurationValue);
				int claim = usb_claim_interface(devicehandle,0);
				int setalternatestatus = usb_set_altinterface(devicehandle,device->config[config].interface[0].altsetting->bAlternateSetting);


				cout << "setconfigstatus:\t" << setconfigstatus << endl;
				cout << "claim:\t" << claim << endl;
				cout << "setalternatestatus:\t" << setalternatestatus << endl;
			}
		}
	}

	if(devicehandle == 0)
	{
		return (0);
	}
	else
	{
		return (devicehandle);
	}
}

this code below is the code i used as a example:

Code:

int missile_do(missile_usb *control, int cmd, int device_type) {
  int a, b, c, d, e;
    /* Two fixed-format initiator packets appear to be required */
    
    if (missile_usb_sendcommand(control, 'U', 'S', 'B', 'C', 0, 0, 4, 0 )) {
      fprintf(stderr, 
	      "missile_usb_sendcommand() failed: %s\n", strerror(errno));
      return -1;
    }
    
    if (missile_usb_sendcommand(control, 'U', 'S', 'B', 'C', 0, 64, 2, 0 )) {
      fprintf(stderr, 
	      "missile_usb_sendcommand() failed: %s\n", strerror(errno));
      return -1;
    }
    
    /* Now the actual movement command! */
    
    a = cmd & MISSILE_LAUNCHER_CMD_LEFT ? 1 : 0;
    b = cmd & MISSILE_LAUNCHER_CMD_RIGHT ? 1 : 0;
    c = cmd & MISSILE_LAUNCHER_CMD_UP ? 1 : 0;
    d = cmd & MISSILE_LAUNCHER_CMD_DOWN ? 1 : 0;
    e = cmd & MISSILE_LAUNCHER_CMD_FIRE ? 1 : 0;
    
    if (missile_usb_sendcommand64(control, 0, a, b, c, d, e, 8, 8 )) {
      fprintf(stderr, 
	      "missile_usb_sendcommand() failed: %s\n", strerror(errno));
      return -1;
    }

int missile_usb_sendcommand64(missile_usb *control, 
			      int a, int b, int c, int d, 
			      int e, int f, int g, int h) {
  
  unsigned char buf[64];
  int  ret;
  
  assert(control != NULL);
  
  ret = claim_interface(control);
  if (ret != 0) {
    return -1;
  }
  
  memset(buf, 0, 64 );
  buf[0] = a;
  buf[1] = b;
  buf[2] = c;
  buf[3] = d;
  buf[4] = e;
  buf[5] = f;
  buf[6] = g;
  buf[7] = h;
  
  if (control->debug) {
    printf("sending bytes %d, %d, %d, %d, %d, %d, %d, %d\n",
	   a, b, c, d, e, f, g, h );
  }
  
  ret = usb_control_msg(control->handle, 0x21, 9, 
			0x2, 0x0, (char*) buf, 64,  control->timeout);

  if (ret != 64) {
    perror("usb_control_msg failed\n");
    return -1;
  }
  
  return 0;
}

Can somebody see what is wrong?

thanks for your help!

Jelte.

Your actual buf is only 8 bytes of data, yet you always send 64?

Salem thanks for your reply!

i test your suggestion tomorrow (it is close at midnight here in holland now) and post the result.

Thanks!

Jelte.

Hello Folks,

I changed my code so my program always send 8 bytes of data to the device (Thanks to Salem)
At that moment i was able to control the device, this means that i could let it fire a missile. after that i had tot restart my PC. and when i restarted was not be able to control the device again.

But the device works OK. with other drivers so the device is alright. So i gues there is some fault in my aplications but i cannot see what is.

could anybody help me?

Code:

#define STOP 	0
#define LEFT 	1
#define RIGHT 	2
#define UP 		4
#define DOWN 	8
#define FIRE 	16

		char msg = 0x00;
	    unsigned char buffer[8];
	    memset(buffer,0,8);

	    int cmd = 0;
	    cmd = msg |= RIGHT;

	    int a = cmd & LEFT ? 1 : 0;
	    int b = cmd & RIGHT ? 1 : 0;
	    int c = cmd & UP ? 1 : 0;
	    int d = cmd & DOWN ? 1 : 0;
	    int e = cmd & FIRE ? 1 : 0;

	    buffer[0] = a;
	    buffer[1] = b;
	    buffer[2] = c;
	    buffer[3] = d;
	    buffer[4] = e;
	    buffer[5] = 0;
	    buffer[6] = 0;
	    buffer[7] = 0;

	   int result = usb_control_msg(misslelauncher_handle, 0x21,9,0x2, 0x0, (char*)buffer, 8,1000);

	   cout << " result is:\t" << result << endl;

Thanks,

Jelte.

EDIT:

well i am back at the first situation, at this moment i can only fire the missile launcher. even ni i try to say when it has to go up or down/ left or right.

and i also discovered that when i send commands that has to make no sense like "15778" it also fires. so always when i send a command , no matter what,it fires. but if i use other software to control the device it works nice. so there must be a bug somewhere in my code.

Do you have a specification for the missile launcher?

it is this one:

http://www.giftideasforeveryone.com/...e-launcher.jpg

id-product: 514 - 0x1130
id-vendor: 4400 - 0x0202

i use:
config - 0.
alternate interface - 0.
claimed interface: 0.

this is some info i got earlier with usbsnoop:

Code:

Connection Information
Port: 2
Speed: Low Speed
Device address: 1
Open pipes: 2
Connection status: Device connected

Device Descriptor
USB version: 1.10
Device class: 0x0 - (Defined at Interface level)
Device subclass: 0x0 - Unknown
Device protocol: 0x0 - Unknown
Control pipe max size: 8 bytes
Vendor ID: 0x1130 (Tenx Technology, Inc.)
Product ID: 0x202 (Unknown)
Product version: 1.0
Manufacturer: Not specified
Product: Tenx Nonstandard Devic
Serial Number: Not specified
Configurations: 1

Solved.

I had to send to init commands to the device, and send my commands in 64-bytes.

Thanks for your help.

Jelte.