USB CDC Communications for Dummies!

[LinkMTech]

Using PBP 2.60A and MPASM for my 1st attempt with USB on a PIC18F2455, I followed these directions:

Copy the PBP\USB18 folder to a new location.
You do not want any files left over from previous versions of PBP, so don't try to copy it into an existing project folder.
Open and compile cdc_demo.bas with the proper chip selected.
Program the chip and test. Done deal.

Copied complete USB18 folder to Documents\MCS to work with.

Wouldn't even start to compile
1st error: Variable USBReserveMemory position request 1024 beyond RAM_END 1023
Did: Opened up PIC18F2455.BAS and enabled BANK4

Started compiling! only to end in errors...
2nd error: ERROR 180.....mcs\usb18\usb18mem.asm 116: RES directive cannot reserve odd number of bytes in PIC18 absolute mode
ERROR 231....usb18mem.asm 116: no memory has been reserved by this instruction
This was repeated for many lines.
Did: Looked at usb18mem.asm line 116 and 117 and on and could only stare.

; (See usbctrltrf.c)
ctrl_trf_state	res	1		; Control Transfer State
ctrl_trf_session_owner res 1		; Current transfer session owner 
wCount		res	2		; Data counter

Now what?
Reading through the forum for this problem and it seems I'm the only one? Can't be that special. Can someone please help a dude out?

[mackrackit]

The USB files need to be in the same directory as your project and it works best if each project has a directory of its own.

Does this example help any?
http://www.picbasic.co.uk/forum/cont...USB-SD-LOGGING

[ScaleRobotics]

Wouldn't even start to compile
1st error: Variable USBReserveMemory position request 1024 beyond RAM_END 1023
Did: Opened up PIC18F2455.BAS and enabled BANK4

Are you sure you are working with 2.60 files?

The BAS file should look like this to start with (no modifications required):

'****************************************************************
'*  18F2455.BAS                                                 *
'*                                                              *
'*  By        : Leonard Zerman, Jeff Schmoyer                   *
'*  Notice    : Copyright (c) 2008 microEngineering Labs, Inc.  *
'*              All Rights Reserved                             *
'*  Date      : 09/12/08                                        *
'*  Version   : 2.60                                            *
'*  Notes     :                                                 *
'****************************************************************

BANKA   $0000, $005F
BANK0   $0060, $00FF
BANK1   $0100, $01FF
BANK2   $0200, $02FF
BANK3   $0300, $03FF
BANK4   $0400, $04FF
BANK5   $0500, $05FF
BANK6   $0600, $06FF
BANK7   $0700, $07FF
'EEPROM  $F00000, $F000FF
LIBRARY "PBPPIC18"

        include "PIC18EXT.BAS"

PORTL   VAR     PORTB
PORTH   VAR     PORTC
TRISL   VAR     TRISB
TRISH   VAR     TRISC

        include "PBPPIC18.RAM"
USBMEMORYADDRESS Con    $400    ' USB RAM starts here

'*-----------------------* EOF 18F2455.BAS *--------------------*

[LinkMTech]

Thanks Dave, I'm gonna study the project for more insight.

Are you sure you are working with 2.60 files?

Just checked the files I have and nope! It's version 2.46!
When I upgraded to 2.60 recently I also downloaded the patch that included the missing PIC18's. Where did I miss getting the latest 2.60 files?

Okay just did some more digging and found the latest 18F2455.bas in the PBP folder not in the USB18 folder. Will keep looking for the rest.

[LinkMTech]

Okay, just copied the 18F2455.bas ver. 2.60 from the PBP folder over to the USB18 folder to replace the ver. 2.46 and it compiled 100%!
Fingers are twitching, but need to wait until the coast is clear here before I can test it.

Thank you for the help.

[mackrackit]

You can have more than one version of PBP installed.
I have directories
C:\PBP_247
C:\PBP_250
C:\PBP_260

Then "point" to the version I want from MCS or FineLine or what ever I am using to invoke the compiler.

So you may want to try a fresh install...

[LinkMTech]

Have heard it so many times before but never from this... what a giddy difference!
To summarize this endeavor:
Make sure 18F2455.bas revision is latest 2.60, found in PBP folder not the file in USB18 folder.
Never assume a copy/pasted Config list is correct! Print out the .inc file for the chip found under MPASM Suite and go through each setting. That's how I found out why there was 0V on VUSB! Turn ON the VREG!

@   __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@   __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
@   __CONFIG    _CONFIG2L, _PWRT_ON_2L & _BOR_SOFT_2L & _BORV_2_2L & _VREGEN_ON_2L 
@   __CONFIG    _CONFIG2H, _WDT_ON_2H & _WDTPS_512_2H
@   __CONFIG    _CONFIG3H, _CCP2MX_OFF_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_OFF_3H
@   __CONFIG    _CONFIG4L, _STVREN_OFF_4L & _LVP_OFF_4L & _XINST_OFF_4L

I think I've the USB bug now. Thanks for the infection!

[Mark J]

Hi Guys,

Malc_c and myself are tinkering with a little project and while he's attacking the hardware side, im looking at the communication side of things and could do with a bit of info for this:

the software on the PC (Not written by us, but freely available for people to use) uses the serial port to communicate to the external circuitry and the way it toggles things is by using the RTS and DTR pins setting them either high or low.

Now my question is we want to setup a PIC18F via USB to be the toggle so thought the CDC comms would be an ideal springboard and I was wondering if when the pic is setup cia CDC comms can the USB detect the RTS/DTR signals? as the programs on the PC dont actually send 'data' but just use those 2 pins to toggle pins on an external device.

Reason we want to use USB is for new machines (ie laptops/netbooks etc) that dont have parallel or serial ports, but still be able to utilise the software as there are quite a few differrent programs that all do the same thing (basically trying to bring the 21st century to the masses LOL!!!! )

Many thanks in advance,

Mark.

[xkocik00]

Hi guys,
can you help me with program USB CDC Communicator on uC PIC18F47J53?
I never use USB, this is my first try.
I tried use the sample code from USB18 (CDC_demo). I tried rewrite the code but without success.
Thx.

[xkocik00]

Proglem solved:

Must use #congif for PIC.

' USB sample program for PIC18F47J53 CDC serial port emulation
' Requires PBP 2.60 or later

Include "cdc_desc.bas" ' Include the HID descriptors

Define OSC 48

#CONFIG
CONFIG WDTEN = OFF ;WDT disabled (enabled by SWDTEN bit)
CONFIG PLLDIV = 3 ;Divide by 3 (12 MHz oscillator input)
CONFIG STVREN = ON ;stack overflow/underflow reset enabled
CONFIG XINST = OFF ;Extended instruction set disabled
CONFIG CPUDIV = OSC1 ;No CPU system clock divide
CONFIG CP0 = OFF ;Program memory is not code-protected
CONFIG OSC = HSPLL ;HS oscillator, PLL enabled, HSPLL used by USB
CONFIG FCMEN = OFF ;Fail-Safe Clock Monitor disabled
CONFIG IESO = OFF ;Two-Speed Start-up disabled
CONFIG WDTPS = 32768 ;1:32768
CONFIG DSWDTOSC = INTOSCREF ;DSWDT uses INTOSC/INTRC as clock
CONFIG RTCOSC = T1OSCREF ;RTCC uses T1OSC/T1CKI as clock
CONFIG DSBOREN = OFF ;Zero-Power BOR disabled in Deep Sleep
CONFIG DSWDTEN = OFF ;Disabled
CONFIG DSWDTPS = 8192 ;1:8,192 (8.5 seconds)
CONFIG IOL1WAY = OFF ;IOLOCK bit can be set and cleared
CONFIG MSSP7B_EN = MSK7 ;7 Bit address masking
CONFIG WPFP = PAGE_1 ;Write Protect Program Flash Page 0
CONFIG WPEND = PAGE_0 ;Start protection at page 0
CONFIG WPCFG = OFF ;Write/Erase last page protect Disabled
CONFIG WPDIS = OFF ;WPFP[5:0], WPEND, and WPCFG bits ignored
#ENDCONFIG


buffer Var Byte[16]
cnt Var Byte


OSCTUNE.6 = 1 ' Enable PLL for 18F47J50 family
Pause 10

USBInit ' Get USB going

'************************************************* ***************
'* Set PORTA, PORTB, PORTC, PORTD PORTE to input/output *
'************************************************* ***************
TRISA = %00100010 ' Set PORTA to output
TRISB = %00001000 ' Set PORTB to output
TRISC = %00---000 ' Set PORTC to output

PortA = %00000000 ' Set PORTA to 0
PortB = %00000000 ' Set PORTB to 0
PortC = %00000000 ' Set PORTC to 0
PortD = %00000000 ' Set PORTD to 0
PortE = %00000000 ' Set PORTE to 0


'************************************************* ***************
'* SET LCD *
'************************************************* ***************
' Define LCD registers and bits
Define LCD_DREG PORTD
Define LCD_DBIT 4
Define LCD_RSREG PORTB
Define LCD_RSBIT 0
Define LCD_EREG PORTB
Define LCD_EBIT 1
DEFINE LCD_LINES 2
DEFINE LCD_COMMANDUS 1500
DEFINE LCD_DATAUS 50

Pause 1000 ' Wait for LCD to start up

'************************************************* ***************
'* LOOP *
'************************************************* ***************
' Wait for USB input
idleloop:
USBService ' Must service USB regularly
cnt = 16 ' Specify input buffer size
USBIn 3, buffer, cnt, idleloop

' Message received
buffer[0] = "O"
buffer[1] = "K"
buffer[2] = 13
buffer[3] = 10
buffer[4] = 0

outloop:
USBService ' Must service USB regularly
USBOut 3, buffer, 5, outloop

Goto idleloop ' Wait for next buffer

[tacbanon]

Hi.. I have windows 7 64bit machine... I download the 64_mchpcdc.inf provided by mackrackit...and copy and paste it in the Windows\sysWOW64 folder, I also reboot the machine but I'm getting exclamation icon(CDC - R232 Emulation Demo) in the devices and printers window. What do you think I'm doing bad? Please give advice.

Thanks in advance,
tacbanon

[mackrackit]

The driver provided with PBP now has 64 bit support added. So you do not need the one I linked to, although it should still work.
I think your problem might be that you copied it to a directory rather than letting the OS install it. Try deleting the file from the sysWOW directory, then do a reboot.
When your project is plugged into your PC windows should bring up the usual dialog asking to install a driver. Do not let windows look for it, point to where the file has been saved to and let windows do the installing. You then should see a virtual com-port in device manager.