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E_Blue
Joined: 13 Apr 2011
Posts: 417
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| Variable never used USB_STRING_DESC_OFFSET? |
 Posted: Fri Aug 12, 2016 8:53 am |
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The CCS USB library have some Warnings but it works anyway, but now I did note this one
Variable never used: USB_STRING_DESC_OFFSET
I don't know if ok or not but now the USB doesn't recognize the device (unknown device).
The device is a PIC18F67J50 CCS version is 5.058.
In the main c file I have
| Code: |
#define USB_CONFIG_PID 0x0000
#define USB_CONFIG_VID 0x0000
#define USB_CONFIG_BUS_POWER 500 //500mA (range is 0..500)
#define USB_CONFIG_VERSION 0x0100 //01.00 //range is 00.00 to 99.99
char USB_STRING_DESC_OFFSET[]={0,4,20};
// Here is where the "CCS" Manufacturer string and "SERIAL DEMO" are stored.
// Strings are saved as unicode.
// These strings are mostly only displayed during the add hardware wizard.
// Once the operating system drivers have been installed it will usually display
// the name from the drivers .INF.
char const USB_STRING_DESC[]={
//string 0
4, //length of string index
0x03, //descriptor type 0x03 (STRING)
0x09,0x04, //Microsoft Defined for US-English
//string 1 - manufacturer
16, //length of string index
0x03, //descriptor type 0x03 (STRING)
'L',0,
'a',0,
'm',0,
'd',0,
'a',0,
'0',0,
'1',0,
//string 2 - product
30, //length of string index
0x03, //descriptor type 0x03 (STRING)
'T',0,
'X',0,
'8,0,
'0',0,
'0',0,
' ',0,
'U',0,
'S',0,
'B',0,
' ',0,
'U',0,
'A',0,
'R',0,
'T',0
};
//set to 1 to use a PIC's internal USB Peripheral
//set to 0 to use a National USBN960x peripheral
#define __USB_PIC_PERIF__ 1
#if __USB_PIC_PERIF__ && defined(__PCH__)
#define USB_CON_SENSE_PIN PIN_E0
#endif
#include <usb_cdc.h> |
The VID/PID is not 0x0000, I have my own.
There's something wrong with this?
Why USB_STRING_DESC_OFFSET are not being used?
_________________
Electric Blue |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19496
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| Posted: Fri Aug 12, 2016 10:42 am |
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That's perfectly all right. It is left over from the old drivers that used this.
VID 0x0000 & PID 0x0000 is never going to be recognised.
PID can be zero (this is a development ID).
However the VID has to be a legitimate vendor ID. Use the CCS UART one that come with the compiler. The Windows drivers will not recognise the device unless it has a legitimate vendor ID. You can write your own .inf file to accept other values, but 1, is the lowest allowed VID (actually Kingston).
Use the VID/PID supplied by CCS. |
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E_Blue
Joined: 13 Apr 2011
Posts: 417
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| Posted: Fri Aug 12, 2016 12:57 pm |
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The VID/PID is not 0x0000, I have my own.
I just changed to 0x0000 when I created the post on purpose.
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Electric Blue |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19496
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| Posted: Fri Aug 12, 2016 1:40 pm |
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If you have your own, you will have to write your own .inf file to support it.
Understand that Windows has the basic USB CDC 'driver', but it has to be told to use this. This is what the .inf file does. It looks at the incoming VID/PID and checks this against the data supplied in it's inf files to find what driver to use.
For the CCS VID/PID, this is in the Drivers\NT,2000,XP,VISTA,7,8,10 directory.
You'll need to take the .inf file there, and edit it to match the VID/PID you are using. Beware though that you won't have the driver signing, so Windows will complain every time this is installed that it is an unsupported driver, and require this to be authorised.
This is different from things like HID devices where basic classes are supported without any inf file. For CDC an inf file is needed. |
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E_Blue
Joined: 13 Apr 2011
Posts: 417
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| Posted: Fri Aug 12, 2016 3:44 pm |
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I thought that HID needs a specific DLL to handle the device (PIC) from PC side.
Is not that way?
I never use the HID because I don't know how to create the DLL.
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Electric Blue |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19496
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| Posted: Sat Aug 13, 2016 2:12 am |
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No, depends on the device.
There are a number of standard HID devices that can be used without any other driver (keyboard, mouse etc..).
Throughout USB, there are standard driver 'classes', that can be supported without an add-on genuine 'driver', but they still require being 'told' what actual driver to use.
Look here:
<https://msdn.microsoft.com/en-gb/library/windows/hardware/ff538820(v=vs.85).aspx> |
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