LinuxQuestions.org - glcd + ftdi + usb

Hi again,

i never unterstand how i can send data to the LCD via kernel.

So i conntect the LCD to an windows computer and record the data with usbsnoop (http://benoit.papillaut.free.ft/usbsnoop).

lsusb -v :

Code:

Bus 002 Device 002: ID 0403:e588 Future Technology Devices International, Ltd 

Device Descriptor:

  bLength                18

  bDescriptorType        1

  bcdUSB              2.00

  bDeviceClass            0 (Defined at Interface level)

  bDeviceSubClass        0 

  bDeviceProtocol        0 

  bMaxPacketSize0        8

  idVendor          0x0403 Future Technology Devices International, Ltd

  idProduct          0xe588 

  bcdDevice            4.00

  iManufacturer          1 Wallbraun-Elect.

  iProduct                2 LCD-USB-Interface V1

  iSerial                3 WE3EFDQG

  bNumConfigurations      1

  Configuration Descriptor:

    bLength                9

    bDescriptorType        2

    wTotalLength          32

    bNumInterfaces          1

    bConfigurationValue    1

    iConfiguration          0 

    bmAttributes        0xc0

      Self Powered

    MaxPower                0mA

    Interface Descriptor:

      bLength                9

      bDescriptorType        4

      bInterfaceNumber        0

      bAlternateSetting      0

      bNumEndpoints          2

      bInterfaceClass      255 Vendor Specific Class

      bInterfaceSubClass    255 Vendor Specific Subclass

      bInterfaceProtocol    255 Vendor Specific Protocol

      iInterface              2 LCD-USB-Interface V1

      Endpoint Descriptor:

        bLength                7

        bDescriptorType        5

        bEndpointAddress    0x81  EP 1 IN

        bmAttributes            2

          Transfer Type            Bulk

          Synch Type              None

          Usage Type              Data

        wMaxPacketSize    0x0040  1x 64 bytes

        bInterval              0

      Endpoint Descriptor:

        bLength                7

        bDescriptorType        5

        bEndpointAddress    0x02  EP 2 OUT

        bmAttributes            2

          Transfer Type            Bulk

          Synch Type              None

          Usage Type              Data

        wMaxPacketSize    0x0040  1x 64 bytes

        bInterval              0

Next i write this small c program:

Code:

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif



#include <stdio.h>

#include <stdlib.h>



#include <usb.h>



#define USBLCD_VENDOR_ID  0x0403

#define USBLCD_PRODUCT_ID 0xe588



extern int usb_debug;



static usb_dev_handle *lcd;

static int interface;

static char *Buffer;

static char *BufPtr;



int drv_UL_open(void) {



  struct usb_bus *busses, *bus;

  struct usb_device *dev;



  lcd = NULL;



  usb_debug = 0;



  usb_init();

  usb_find_busses();

  usb_find_devices();

  busses = usb_get_busses();



  for (bus = busses; bus; bus = bus->next) {

    for (dev = bus->devices; dev; dev = dev->next) {

      if ((dev->descriptor.idVendor == USBLCD_VENDOR_ID) &&

          (dev->descriptor.idProduct == USBLCD_PRODUCT_ID)) {

        printf ("USB LCD gefunden\n");

        lcd = usb_open(dev);

        if (usb_claim_interface(lcd, interface) < 0) {

          printf ("FEHLER : usb_claim_interface\n");

          return -1;

          }

        else {

          printf ("usb_claim_interface erfolgreich\n");

          

        }

      }

    }

  }

  return -1;

}



int drv_UL_close(void) {

  usb_release_interface (lcd, interface);

  usb_close(lcd);

  printf (" LCD wieder freigegeben\n");

}



int drv_CMD(void) {

  char *cmdBuf, *cmdPtr, *inBuf, *inPtr;

  int rv, i, inrv;



  inBuf = (char *) malloc(1024);

  if (inBuf == NULL) {

    printf ("kann speicher nicht reservieren!\n");

    return -1;

  }

  inrv = usb_bulk_read(lcd, 0x81, inBuf, 1000, 1000);

  printf ("Ergebnis von usb_bulk_read: %d\n", inrv);



  cmdBuf = (char *) malloc(1024);

  if (cmdBuf == NULL) {

    printf ("Kann Speicher für cmd nicht reservieren!\n");

    return -1;

  } 



  cmdPtr=cmdBuf;

  *cmdPtr++=0x04;

  *cmdPtr++=0x00;

  *cmdPtr++=0x03;

  *cmdPtr++=0x00;

  *cmdPtr++=0x00;

  *cmdPtr++=0x4c;

  rv=usb_bulk_write (lcd, 0x02, cmdBuf, 6, 1000);

  printf ("ergebnis von usb_bulk_write2 %d\n", rv);



  cmdPtr=cmdBuf;

  *cmdPtr++=0x08;

  *cmdPtr++=0x03;

  *cmdPtr++=0xFD;

  *cmdPtr++=0x54;

  *cmdPtr++=0x68;

  *cmdPtr++=0x65;

  *cmdPtr++=0x6f;

  *cmdPtr++=0x20;

  *cmdPtr++=0x53;

  *cmdPtr++=0x63;

  *cmdPtr++=0x68;

  *cmdPtr++=0x6e;

  *cmdPtr++=0x65;

  *cmdPtr++=0x69;

  *cmdPtr++=0x64;

  *cmdPtr++=0x65;

  *cmdPtr++=0x72;

  for (i=1; i <=1007; ++i) {

    *cmdPtr++=0x20;

  }

  rv=usb_bulk_write (lcd, 0x02, cmdBuf, 1024, 1000);

  printf ("ergebnis von usb_bulk_write3 %d\n", rv);



  inPtr=inBuf;

  for (i=1; i <= inrv; ++i) {

  printf ("Inhalt inBuf %x\n", *inPtr++);

  }



  free (inBuf);

  free (cmdBuf);

}



int main(int argc, char *argv[])

{

  drv_UL_open();

  drv_CMD();

  drv_UL_close();



  return EXIT_SUCCESS;

}

All the program to is, write my name to the LCD.

Take a look at // First DATA to LCD, the second and third byte are the lengt of data that follow, but dont know for what is 0x04 and 0x4f?

// Second DATA to LCD
First byte 0x08 ?
Second and third byte = 0x03FD = lengt of the follow data
rest is easy, my Name and some spaces.

Anyone know for what is 0x04, 0x4f and 0x08?

Hope you can read my english.

mfg
tooly