Does Anybody try EX_USB_SERIAL ?

[Fabri]

Hi,

As last posted I need information about ex_usb_serial because the PIC receve from USB but don't send back an answer.

Somebody help me on to find a problem?

Thanks,

[Guest]

i used the example and built a usb to 485 converter the programming only took 1/2 hour. if you look througth the files everything is there

[Guest]

Hi,

I dont find any USB to 485 converter example in my ccs examples file.

Would you like to confirm me the name of file ?

Thanks,

[newguy]

You don't understand. That person said that they wrote their own USB - RS485 converter based on the examples that CCS provides.

[Fabri]

When PIC receve one byte from RS232 save it on buffer and start to send data on USB.
In the follow part of routine the return in my application is "FALSE".

[drolleman]

the usb - 485 converter was built on the serial2 example with only 10 lines of extra code. when the usb sends a char then it puts on the uart to trasmit. and when the uart interups with a char it puts it on the usb.

[Fabri]

Hi,

I tryed example2 but the problem is the same. Pic fill the buffer but don't send it on USB. Serial2 use the same routine of Serial so I think it isn't a problem of routines but the configuration of them.

I need to solve a problem in a short time, so do you want help me ?

1) Do you change any data in usb_desc_cdc.h or other routine ?
2) Where I can get inf file to configure virtual com on PC ? Actualy I'm using a file gave me by forum user but he doesn't support me about.

CCS said:

[drolleman]

the inf file you can get from microchip's serial example . i modified it for my use the pid/vid were chaned from their example. this will create the "virtual serial port".

[Fabri]

Hi,
I understand you got it somewere, this isn't a help for me.

I searched it on line, I found a copy but I don't understand if the problem is in it. So I need to try an tested version now to understand if the problem is in inf file or not.

1) Would you show me the link were is it and the way to modify it?

As I posted:

[drolleman]

usb_cdc_putc(getc()); puts char on the usb up to terminial

usb_cdc_kbhit() tests for is char in recieve buffer?

value = usb_cdc_getc(); gets the charater from the usb

usbview.exe from microsoft shows connected usb devices

download the usb to serial example from microchip
the inf file needs to be changed to your settings vid/pid

the vid and the pid you will get from usbview

here is what i use

[Version]
Signature="$Windows NT$"
Class=Ports
ClassGuid={4D36E978-E325-11CE-BFC1-08002BE10318}
Provider=%MCHP%
LayoutFile=layout.inf
DriverVer=08/17/2001,5.1.2600.0

[Manufacturer]
%MFGNAME%=DeviceList

[DestinationDirs]
DefaultDestDir=12

[SourceDisksFiles]

[SourceDisksNames]

[DeviceList]
%DESCRIPTION%=DriverInstall, USB\VID_0461&PID_0033

;------------------------------------------------------------------------------
; Windows 2000/XP Sections
;------------------------------------------------------------------------------

[DriverInstall.nt]
CopyFiles=DriverCopyFiles
AddReg=DriverInstall.nt.AddReg

[DriverCopyFiles]
usbser.sys,,,0x20

[DriverInstall.nt.AddReg]
HKR,,DevLoader,,*ntkern
HKR,,NTMPDriver,,usbser.sys
HKR,,EnumPropPages32,,"MsPorts.dll,SerialPortPropPageProvider"

[DriverInstall.nt.Services]
AddService=usbser, 0x00000002, DriverService

[DriverService]
DisplayName=%SERVICE%
ServiceType=1
StartType=3
ErrorControl=1
ServiceBinary=%12%\usbser.sys

;------------------------------------------------------------------------------
; String Definitions
;------------------------------------------------------------------------------

[Strings]
MCHP="Microchip Technology Inc."
MFGNAME="Microchip Technology Inc."
DESCRIPTION="Communications Port"
SERVICE="USB RS-232 Emulation Driver"

[Guest]

The inf file is the same I used.

I changed PC, from notebook to desktop, and the example start to work.
On my notebook doesn't work. It's really strange.

In my example PIC send back what it receved on USB.

Anyway after a few transmission the system stop to work also with desktop. The buffer is full of characters. The routine where it stop is the same I posted "int8 usb_tbe(int8 endpoint)()".


When work st=0x40 and endpoint=0x02
When stop to work st=0xc8 and endpoint=0x02

Shall the problem is hardware ?
I'm using PIC18F2455, crystall 16 Mhz with PLL4,CPUDIV1 fuses set.
I don't use any pull-up on USB and no more components at this time.
The CCS compiler is the latest version
Windows version is W2K.

Thank for help.

[Guest]

doesn't sound like the hardware you have to empty the buffer before it overloads.

[rwyoung]

[Guest]

As I can see "USBVIEW" confirm the complete enumeration:

[drolleman]

ost your code the unit is working. there is no need for pullup resistors. the only thing it must be in the code.