USBSERVICE + serout2 problem

[EToscano]

Good afternoon everybody, I need some asistance with a problem with a USB/Serial program.
I'm posting this in both the USB and SERIAL groups.

This is running on a 18f4550@48mhz using DT's "usb_asm_service".


the thing is if in my main loop I put:

baud485 con $4006

mainloop:


high en485
serout2 tx485,baud485,["!",s485(0),s485(1),s485(2),s485(3),s485(4),s485(5), _
s485(6),s485(7),s485(8),s485(9),s485(10),s485(11), _
s485(12),s485(13),s485(14)]
low en485

pause 1000
goto mainloop


end



if the usb cable is not connected, I get the sent bytes on my 485 bus, but as soon as I plug the usb cable, I start loosing some bytes(at least 1) of every cycle.

this is not the actual code, but it does the same thing basically.

It seems to me as if during the serout2 instruction the usbservice happens it kills the byte being transmited at the time.
Do I make any sense?

What I need is to be able to process serial comm using serout2 to other devices even when the device is connected to the usb host.

Hopefully this is clear enough so someone can share some tips.


Best regards

Eduardo Toscano
Seneca Sistemas

[mackrackit]

I deleted your other post as there is no need to double post.

You may need to post your complete code also.

[Darrel Taylor]

Anytime you are using interrupts (other than ON INTERRUPT), it interrupts things.
USB_ASM_Service uses USB interrupts that happen quite frequently.

Software timed routines like SEROUT2, PAUSE, PULSIN/OUT etc. Will lose time that they don't know about.

When using interrupts, Hardware devices should be use instead of software commands.
Instead of SEROUT2, use HSEROUT with the USART.

PAUSE ... use a timer.
PULSIN ... use a CCP module.
COUNT ... use a Timer

There are still many PBP commands you can use without problems.
But, if if they require specific timing thru software, that timing will be disturbed.

[aberco]

Hi Darrel,
I'm actually back on USB development, there is quite a bit of new stuffs! your USB_ASM_Service routine is very exciting.

If I understand correctly the timing issue will also "kill" I2CRead/Write, Shiftin/Shiftout, LCDout... There's hardware modules for SPI and I2C, even if they are not used by these instructions. However there's not much solution for driving the LCD.

Is the delay introduced by the interrupt that long? I mean, some processes does not require an extreme regularity of clocking/data signals, an intelligent LCD display should probably cope with this.

However I haven't been able to experiment with it yet... I have managed to compile and run successfully the DCD demo on a PIC18F13K50. Adding the USB_ASM_Service routine and commenting the USBService/USBInit in the demo makes the board unable to declare itself anymore.

I've also tried running both the interrupt and polled USB servicing to display the status of "PLUGGED" on a LED but nothing happens. The rest of the demo works fine though.

Any lead for this issue?
Thanks in advance for your time

[mackrackit]

However I haven't been able to experiment with it yet... I have managed to compile and run successfully the DCD demo on a PIC18F13K50. Adding the USB_ASM_Service routine and commenting the USBService/USBInit in the demo makes the board unable to declare itself anymore.

Can you post the non-working code?

[aberco]

Yep sure!

ASM
CONFIG CPUDIV=NOCLKDIV ; CPU runing at full speed
CONFIG USBDIV=OFF ; Low speed USB clock diviser disabled, not used here
CONFIG FOSC=HS ; Use of High Speed crystal oscillator
CONFIG PLLEN=ON ; Enable PLL multiplier, 12Mhz oscilator x 4
CONFIG PCLKEN=ON ; Primary clock source is enabled
CONFIG FCMEN=OFF ; Failsafe clock off
CONFIG IESO=OFF ; Oscillator switchover mode disabled
CONFIG WDTEN=ON ; Watchdog timer on
CONFIG WDTPS=512 ; Watchdog divider is 512
CONFIG MCLRE=OFF ; Disable MCLR pin, enable RC3
CONFIG STVREN=ON ; Stack full/underflow will cause reset
CONFIG LVP=OFF ; Low voltage programming disabled
CONFIG BBSIZ=OFF ; 512kW block boot size
CONFIG XINST=OFF ; Extended instruction mode disabled
ENDASM

Include	"cdc_desc.bas"	' Include the CDC descriptors
INCLUDE "USB_ASM_Service.pbp"  ' USB Init and Service interrupt routines

'Define pin function
TRISA = %00000000 'PortA all digital output
TRISB = %00000000 'PortB all digital output
TRISC = %00000000 'PortC all digital output

ANSEL = %00000000 'Disable analog input on other pins
ANSELH = %00000000 'Disable analog input on other pins

'Define weak pullups
WPUA = %00000000 'No weak pullup on portA
WPUB = %00000000 'No weak pullup on portB
    
Define  OSC     48

buffer VAR BYTE[16]
cnt VAR BYTE Byte
i VAR BYTE

'Pin function declaration

GreenLED VAR PORTC.6
RedLED VAR PORTC.3
BlueLED VAR PORTC.4

pwmvalue VAR BYTE

'Program start

pwmvalue = 130
HPWM 1,pwmvalue,32767

LOW REDLED
LOW BLUELED
LOW GREENLED

Pause 10

USBInit	' Get USB going

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

i = 0

SELECT CASE buffer
        CASE "R"
            HIGH REDLED
            LOW GREENLED
            LOW BLUELED
        CASE "G"
            LOW REDLED
            HIGH GREENLED
            LOW BLUELED
        CASE "B"
            LOW REDLED
            LOW GREENLED
            HIGH BLUELED
        CASE "C"        
            LOW REDLED
            HIGH GREENLED
            HIGH BLUELED
        CASE "M"        
            HIGH REDLED
            LOW GREENLED
            HIGH BLUELED
        CASE "Y"
            HIGH REDLED
            HIGH GREENLED
            LOW BLUELED
        CASE "W"
            HIGH REDLED
            HIGH GREENLED
            HIGH BLUELED
        CASE "K"
            LOW REDLED
            LOW GREENLED
            LOW BLUELED
        CASE ELSE
            i = 1
END SELECT

' Message received

IF i = 0 THEN
	buffer[0] = buffer
	buffer[1] = "-"
	buffer[2] = "O"
	buffer[3] = "k"
	buffer[4] = 13
	buffer[5] = 10
	buffer[6] = 0
ELSE
        buffer[0] = "E"
	buffer[1] = "r"
	buffer[2] = "r"
	buffer[3] = "."
	buffer[4] = 13
	buffer[5] = 10
	buffer[6] = 0
ENDIF	
	

outloop:
	USBService		' Must service USB regularly
	USBOut 3, buffer, 7, outloop
	Goto idleloop		' Wait for next buffer

It is a quick and dirty modification of the CDC demo. A RGB LED takes the color code sent on the USB port as a letter. The code works, but commenting USBInit, and both USBService kill it.

[mackrackit]

LOW REDLED
LOW BLUELED
LOW GREENLED

Pause 10

USBInit * *' Get USB going

When using Darrel's includes do not add any USBInit.

[rsocor01]

If I understand correctly the timing issue will also "kill" I2CRead/Write, Shiftin/Shiftout, LCDout... There's hardware modules for SPI and I2C, even if they are not used by these instructions. However there's not much solution for driving the LCD.

I use I2CRead/Write and LCDout with a USB connection at the same time with no problems. However, I haven't tried using Shiftin/Shiftout and USB at the same time.

I got the LCDout command working together with the USB connection thanks to the great help from DT. You can see the details in the next link

http://www.picbasic.co.uk/forum/show...4&daysprune=-1

Robert

[aberco]

Hi mackrackit and thanks for your attention,

"When using Darrel's includes do not add any USBInit"

Yes I know that, however if I comment USBInit and USBService it kill the program. It still run but it is not seen by the computer anymore. The include seems to be effective as I can use the PLUGGED, RX_READY and TX_READY variables inside my program without declaring them. They all read 0 whatever is happening though...

Was it tested on a 13/14K50 before? With CDC profile? or am I doing something wrong? The usage seems pretty straightforward though...

rsocor01, it is nice to know that all these can be used. Darrel's code for handling the USB is a nice time saver over handling USBService manually. It's just a nightmare when the program gets complicated.

Thanks to both of you,
Antoine.

[mackrackit]

Was it tested on a 13/14K50 before? With CDC profile? or am I doing something wrong? The usage seems pretty straightforward though...

I never have but I am sure Darrel did...

buffer[0] = buffer

That will not work.

[aberco]

Ok, let's just go back to the original demo without any alteration:

' USB sample program for PIC18F4550 CDC serial port emulation
'  Requires PBP 2.60 or later

'  Compilation of this program requires that specific support files be
'  available in the source directory.  For detailed information, see
'  the file PBP\USB18\USB.TXT.

ASM
CONFIG CPUDIV=NOCLKDIV ; CPU runing at full speed
CONFIG USBDIV=OFF ; Low speed USB clock diviser disabled, not used here
CONFIG FOSC=HS ; Use of High Speed crystal oscillator
CONFIG PLLEN=ON ; Enable PLL multiplier, 12Mhz oscilator x 4
CONFIG PCLKEN=ON ; Primary clock source is enabled
CONFIG FCMEN=OFF ; Failsafe clock off
CONFIG IESO=OFF ; Oscillator switchover mode disabled
CONFIG WDTEN=ON ; Watchdog timer on
CONFIG WDTPS=512 ; Watchdog divider is 512
CONFIG MCLRE=OFF ; Disable MCLR pin, enable RC3
CONFIG STVREN=ON ; Stack full/underflow will cause reset
CONFIG LVP=OFF ; Low voltage programming disabled
CONFIG BBSIZ=OFF ; 512kW block boot size
CONFIG XINST=OFF ; Extended instruction mode disabled
ENDASM

Include	"cdc_desc.bas"	' Include the CDC descriptors
INCLUDE "USB_ASM_Service.pbp"  ' USB Init and Service interrupt routines

'Define pin function
TRISA = %00000000 'PortA all digital output
TRISB = %00000000 'PortB all digital output
TRISC = %00000000 'PortC all digital output

ANSEL = %00000000 'Disable analog input on other pins
ANSELH = %00000000 'Disable analog input on other pins

'Define weak pullups
WPUA = %00000000 'No weak pullup on portA
WPUB = %00000000 'No weak pullup on portB
    
Define  OSC     48

buffer	Var	Byte[16]
cnt	Var	Byte

'Pin function declaration

Pause 10

'	USBInit			' Get USB going

' 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] = "H"
	buffer[1] = "e"
	buffer[2] = "l"
	buffer[3] = "l"
	buffer[4] = "o"
	buffer[5] = " "
	buffer[6] = "W"
	buffer[7] = "o"
	buffer[8] = "r"
	buffer[9] = "l"
	buffer[10] = "d"
	buffer[11] = 13
	buffer[12] = 10
	buffer[13] = 0

outloop:
'	USBService		' Must service USB regularly
	USBOut 3, buffer, 14, outloop

	Goto idleloop		' Wait for next buffer

... does not work.

I must say that after 2 days of digging the forum and the internet I am starting to get clueless about what to do to solve it. Is there a timer or an interrupt register to set up manually in order to run it properly? I could try to run it on a 18F4550 board I have but that won't solve the problem for my 13K50 project.

Also, I found out that USB_ASM_Service.pbp does not work in conjunction with INDT_INTS-18.bas and SPWM_INT.bas from Darell. I will need at least the latter, so maybe I should find another solution than actually trying to use USB_ASM_Service.pbp.

Any idea for troubleshooting this? or pointing to an interrupt solution that I could use? I'm starting to get clueless. Any help greatly appreciated!

BTW, I'm running PBP 2.60 in MCS 4.0.0.0, in conjunction with MPLAB 8.53.

[mackrackit]

Looks like we will have to wait till Darrel gets back to help with his includes, I do not see where the problem is.

If you do not use USB_ASM_Service.pbp the USB works?

[aberco]

Yes, it does not matters if I comment USB_ASM_Service.pbp or not. The demo does work perfectly with USBINIT and USBService, but as soon as I comment these I loose USB enumeration.

I also wish to use USB_ASM_Service.pbp in conjunction with Darrel's SPWM_INT.bas which does not seems possible right now (it gives an INTHAND symbol cannot be refefined error, which is normal because it appears twice). I could do the USBService interrupt with the SPWM interrupt at the same time... I do not have tight frequency requirements for the PWM signal (about 100Hz or more), what I'm interested in is the duty cycle. The main idea of my project is based on controlling the brightness of 3 LEDs by sending serial commands through USB CDC. I have to use the 13K50 for this application, but there's only one ECCP module.

But first things first, making USB_ASM_Service.pbp work with the demo! Hopefully Darrel can spare a little time to check what is going wrong here.

[mackrackit]

I am not at a place to test this to see if it makes a difference or not...

I (for no good reason) have this after all DEFINES and Variable declarations.

Include	"cdc_desc.bas"	' Include the CDC descriptors
INCLUDE "USB_ASM_Service.pbp"  ' USB Init and Service interrupt routines

Which is where your first USBInt is...

And maybe for the other ISR.
From USB_ASM_SERVICE.pbp

To use other high priority interrupts you can add the define *
'* DEFINE INT_HOOK handlers *
'* handlers will be called on each high priority interrupt *
'* The handlers must be ASM Interrupt compatible

[aberco]

I can easily do the test, moved the includes just before the start of the main program with the same result, does not enumerate . Still work like a charm the old way though.

Tomorrow I will get my 18F4550 board out and try.

[aberco]

I could not get the CDC demo to run on my 18F4550 board, (though, 3 years ago it was running fine... but since then I changed PBP, MCS and PMLAB versions...). I however did no progress regarding the 13K50 issue in three weeks, I just can't figure what's wrong, what to modify, or where to look for. Is there a need to enable an hardware timer to run the interrupt?

Unfortunately the same apply for running more than one interrupt-based routine from Darrel, using the DEFINE INT_HOOK handlers. I have not been able to find any example for it, and I don't really understand how to makes it work.

Any help would be greatly appreciated

[mackrackit]

Which version of PBP are you currently using?

[aberco]

I'm running PBP 2.60 in MCS 4.0.0.0, in conjunction with MPLAB 8.53.

[mackrackit]

Some things have changed with PBP 2.6. Maybe that is the problem?
Have you seen this?
http://www.picbasic.co.uk/forum/show...0301#post80301

[aberco]

Yes I know this post was my starting point.

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.

That is exactly what I did, and it does work.

It is when I add Darrel USB_ASM_Service.pbp and remove the original USBINIT/USBSERVICE that the PIC does not enumerate anymore...

A last resort idea would be to USBSERVICE using a Timer0 interrupt, but Darrel solution adds more fancy controls such as the ability to know if the link is established, or if Tx/Rx operations are available/possible. This would be a nice addition to prevent any USB buffer fill and lock-up of the PIC.

(PS. I tried to send a private message to Darrel about 3 weeks ago but had no reply).

[mackrackit]

Darrel has been out of town. He is sorta back now so maybe he will be able to help now.

[aberco]

Ok, I tried some debug attempt with some LED blink, which show me that the interrupt handler "DoUSBSERVICE" within Darrel's routine is not called.

This is what should do the USBSERVICE. Is there something to do to link this handler to an interrupt? should I configure a timer for this? I have deactivated the watchdog timer if that could explain why the handler is not working...
I do not understand what triggers this interrupt. I've tried to call it manually within the USBIN loop using a GOSUB, but that does not help getting the PIC to enumerate...

[Darrel Taylor]

Aberco,

Sorry, I deleted your modification because it was silly to use Timer0 for USB interrupts, and it won't detect Plugged, RX, or TX, that way.
Plus I don't want that code floating around.
Some Patience is required until I get settled. I don't have any computers or internet access at night right now.

I believe that all you need to do is change the USBIE and USBIF bits because Microchip moved them in the 13K50/14K50.
They used to be PIE2.5 and PIR2.5 in the 4550 family. Now they are PIE2.2 and PIR2.2 in those chips.

Please download the file again to start from scratch, then change to ...

USBIE              VAR PIE2.2        ; USB funnel Interrupt Enable
USBIF              VAR PIR2.2        ; USB Interrupt Flag

[aberco]

Simple enough, and worked great!

May I ask what drives the USBSERVICE interrupt?
Also I would like to use DT_INTS-18.bas in the program as well but I don't understand how to use the interrupt hook handler, and could not find any example of it.

Take your time, there's no hurry, I can now spend some time to play with USB data transmission

Thanks a lot for the great help.

[aberco]

Or... is there a way to turn DT_HID260 into a DT_CDC260? is there something I could use in the cdc_desc.bas file (contained in the USB demo folder) to do such thing or is it more complicated than transferring a series of values?

[Darrel Taylor]

> May I ask what drives the USBSERVICE interrupt?
The USB module itself generates many different interrupts.

> Also I would like to use DT_INTS-18.bas in the program as well
> but I don't understand how to use the interrupt hook handler,
> and could not find any example of it.
That is not possible with USB_ASM_Service.pbp.
All interrupts used with the "Hook" can only be ASM (assembly language) type interrupts.

> Or... is there a way to turn DT_HID260 into a DT_CDC260?
No, but I could write a DT_CDC program. If I ever get my computers and internet access at home.

[aberco]

Ok, that was my understanding of the interrupt hook handler. Hmmm that will make things more difficult. A DT_CDC would be extremely helpful in my case, but that is a lot to ask...

I will think about it, currently I have two different application, both that need to use the CDC profile (HID could work, but that would make programming more difficult on the computer side... also it is nice to use a terminal to drive the device without any dedicated software).
One application needs Timer1 to do precise timing sampling, the second needs your multiple software PWM routine to drive 3 LEDs.

[Darrel Taylor]

aberco,

Here's a little ditty that should get you going with servicing CDC and DT-INTS-18.
Hope it helps.

DEFINE OSC 48

INCLUDE "cdc_desc.bas"

;--- Setup Interrupts ------------------------------------------------------
INCLUDE "DT_INTS-18.bas"     ; Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ; Include if using PBP interrupts

ASM
INT_LIST  macro     ; IntSource,          Label,  Type, ResetFlag?
        INT_Handler     USB_INT,  _DoUSBSERVICE,   ASM,  yes
        INT_Handler     INT_INT,    _Handle_INT,   PBP,  yes
    endm
    INT_CREATE             ; Creates the Low Priority interrupt processor

    INT_ENABLE  USB_INT
    INT_ENABLE  INT_INT
ENDASM


;----[Initialise USB and Interrupts]----------------------------------------
    PAUSE 100                    ; Allow VUSB to stabilize
    USBINIT                      ; initialize the USB driver
    USBSERVICE                   ; service it once
    UIE = $7F                    ; enable USB interrupts
    UEIE = $9F                   ; enable USB Error interrupts

;----[Main program loop]----------------------------------------------------
Main:
    ; some code here
GOTO Main

;----[Interrupt handler -- Service USB]-------------------------------------
DoUSBSERVICE:
      USBSERVICE                   ; Run the SERVICE routines
@ INT_RETURN

;----[Interrupt handler -- INT]
Handle_INT:
 ; something here
@ INT_RETURN

[aberco]

Thanks Darrel, I will play with this in a couple of days, it looks like this would do the trick.

What I really like in your DT_HID260 is that all USB dependent declaration are clearly listed within the program. I feel it is better and self-contained than digging cdc_desc.bas to modify the values, but maybe it works just the same at the end. I am now planning to use a bootloader as well, so I will have to check if two independent USB setup can be used one after the other without creating conflict.

[aberco]

Well I must say that I'm still banging my head against USB CDC... I've tried this, the led does blink for 1 1/2 cycles and everything hangs and the pic does not enumerate.
Now, is it because USB is serviced before the device is attached?

I changed the interrupt from "ASM" to "PBP" (USBSERVICE is a PBP instruction).

'*******************************************************
'Config fuses for PIC18LF14K50
'*******************************************************

ASM
CONFIG CPUDIV=NOCLKDIV ; CPU runing at full speed
CONFIG USBDIV=OFF ; Low speed USB clock diviser disabled, not used here
CONFIG FOSC=HS ; Use of High Speed crystal oscillator
CONFIG PLLEN=ON ; Enable PLL multiplier, 12Mhz oscilator x 4
CONFIG PCLKEN=ON ; Primary clock source is enabled
CONFIG FCMEN=OFF ; Failsafe clock off
CONFIG IESO=OFF ; Oscillator switchover mode disabled
CONFIG WDTEN=ON ; Watchdog timer on
CONFIG WDTPS=512 ; Watchdog divider is 512
CONFIG MCLRE=OFF ; Disable MCLR pin, enable RC3
CONFIG STVREN=ON ; Stack full/underflow will cause reset
CONFIG LVP=OFF ; Low voltage programming disabled
CONFIG BBSIZ=OFF ; 512kW block boot size
CONFIG XINST=OFF ; Extended instruction mode disabled
ENDASM


DEFINE OSC 48          
DEFINE LOADER_USED 1

'*******************************************************
'Init for PIC18LF14K50
'*******************************************************

'Set ADC pins to digital operation
ADCON0 = %00000000 'turn ADC OFF
CM1CON0 = %00000000 'disabling comparator module 1
CM2CON0 = %00000000 'disabling comparator module 2

'Define pin function
TRISA = %00000000 'PortA all digital output
TRISB = %00000000 'PortB all digital output
TRISC = %00000000 'PortC all digital output

ANSEL = %00000000 'Disable analog input all pins
ANSELH = %00000000 'Disable analog input all pins

RedLED VAR PORTC.3

INCLUDE "cdc_desc.bas"

;--- Setup Interrupts ------------------------------------------------------
INCLUDE "DT_INTS-18.bas"     ; Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ; Include if using PBP interrupts

ASM
INT_LIST  macro     ; IntSource,          Label,  Type, ResetFlag?
        INT_Handler     USB_INT,  _DoUSBSERVICE,   PBP,  yes
    endm
    INT_CREATE             ; Creates the Low Priority interrupt processor

    INT_ENABLE  USB_INT
ENDASM

;----[Initialise USB and Interrupts]----------------------------------------
    PAUSE 100                    ; Allow VUSB to stabilize
    USBINIT                      ; initialize the USB driver
    USBSERVICE                   ; service it once
    UIE = $7F                    ; enable USB interrupts
    UEIE = $9F                   ; enable USB Error interrupts

;----[Main program loop]----------------------------------------------------
Main:
HIGH RedLED
PAUSE 200
LOW REDLED
PAUSE 200
GOTO MAIN

;----[Interrupt handler -- Service USB]-------------------------------------
DoUSBSERVICE:
      USBSERVICE                   ; Run the SERVICE routines
@ INT_RETURN

END

[Darrel Taylor]

Try moving the USB enable to after the initialization.

;    INT_ENABLE  USB_INT
ENDASM

;----[Initialise USB and Interrupts]----------------------------------------
    PAUSE 100                    ; Allow VUSB to stabilize
    USBINIT                      ; initialize the USB driver
    USBSERVICE                   ; service it once
    UIE = $7F                    ; enable USB interrupts
    UEIE = $9F                   ; enable USB Error interrupts
@ INT_ENABLE  USB_INT

Enabling before USBINIT probably wasn't a good idea on my part.

And while USBSERVICE is a PBP statement, the code is all ASM and does not use any of PBP's system variables. So change it back to ASM "type".

[aberco]

Hmm that make sense... I made the changes but that doesn't work any better though.

A little troubleshooting, if I plug the USB connector halfway (just Power) the LED blink, however it stops a couple 100's ms after D+/D- get connected.

[Darrel Taylor]

I may have asked you this in another thread, sorry if I did ... but ...

What size capacitor do you have on VUSB.
0.22 - 0.47uF?

[aberco]

Hardware is fine, USB does work with DT_HID260. I have two prototype boards with 220nF, both are ok. Config fuses are OK too, should be software-related.

[Darrel Taylor]

Well, I've got a 14K50 here now, and it enumerates and holds the USB just fine.
So far I haven't got a single blink out of RC3 yet though.

Not sure what's going on there, but I'll play with it some more tomorrow.

I'll add some USBIN/USBOUT statements too and make sure CDC is really working.

What operating system are you using?
Win7-64 here.

[aberco]

Well yeah, you're right! it does enumerates!!! and it even blink on my application.

What's happening, this is due to my programming setup and the specific hardwiring of the 18F1xK50. The USB lines D+/D- are shared with PGD and PGC, and it seems that in order for USB to work, the programmer has to be disconnected. For this purpose, I have purchased microchip special module for the 18F1xK50, that adapt the programming levels of the programmer to something that the PIC can accept, but at the same time allows to leave plugged the USB cable of the host computer by protecting the D+/D- lines from programming voltages.

Well I realized early on that it did not work, and I had to disconnect PGD and PGC in order to have USB working, so I added a set of switches on my programming cable.

Now I've been able to verify different behavior on USB programs, especially DT_HID260 which is the only one "powerful" enough to enumerate even with PGD/PGC connected to the programmer. All others required those lines disconnected to enumerate.



Now, about your little CDC routine, it does work well with PGD/PGC disconnected. But when I connect them back the USB connexion drops and the PIC crashes. No big deal, but I'll have to make sure that communication is established when servicing, and especially turn it of before unplugging USB.

Now I'll try to add USBIN/USBOUT statements and play a bit with communication before building the full program around it. Thanks for your great help!

[aberco]

Well, more progress, and so far so good!
In understood that your program proposal is actually a stripped off version of your USB_ASM_Service routine. I have been able to use it within my program now, but calling the DoUSBSERVICE routine using the USB interrupt triggered by your interrupt routine.

So far so good, it does enumerate, and more importantly I have all the control options given by the connected state, Tx/Rx ready. The LED always blink regardless of what the USB is doing.

The only thing that seems to break the code is "DEFINE RESET_ORG 2048 ' Start code at $0800", I added this at the very top to be ready for the bootloader implementation (leaving 1 kWords available). Probably a problem of memory bank and interrupt...

Seems to work very well so far... I am not posting the code until it is ok with you.

[aberco]

Trying to implement a "console like" behavior but cannot get it to work.

I'm using RX_Ready to read USB and then entering the desired reaction regarding the received command. However it seems that after doing an USBIn command, RX_Ready does not stay = 0 for very long, even if absolutely no data is received.

Is RX_Ready indicating a capacity to receive data (buffer not full), just like TX_Ready? In that case I cannot use this to trigger an event upon packet receive...

To better explain it here is some very dirty code.

MainLoop:

ARRAYWRITE USBBuffer, [">"]
GOSUB DoUSBOut

GOSUB DoUSBIn

SELECT CASE USBBuffer [0]
    CASE "A", "a"
        GOSUB  EchoData
        ARRAYWRITE USBBuffer, ["OK", 10, 13]
        Gosub DoUSBOut
    CASE ELSE
        GosuB EchoData
        ARRAYWRITE USBBuffer, ["Error", 10, 13]
        GOSUB DoUSBOut
END SELECT

PAUSE 1000

GOTO MainLoop

'*******************************************************
'Echo sent frame back
'*******************************************************
EchoData:

GOSUB DoUSBOut
ARRAYWRITE USBBuffer, [10, 13]
GOSUB DoUSBOut

RETURN

I'm confused yet about very simple things, like how to clear the buffer between requests. Also here it is polled every seconds, because I do not know how to trigger the event upon packet received... Tried to look for helpful examples without any luck.

[Darrel Taylor]

If you are trying to tie together USB_ASM_Service and the routine I gave in this thread, it won't work as is.

CDC uses a different endpoint than HID.

[aberco]

Well, I managed to make it all work... possibly partially but so far so good!

I can send and receive 32 bytes packets. However as you said I may have not modofied everything which makes TX_Ready and RX_Ready non functional. However they are tied to USB registers and should not be dependent to endpoints if my understanding of the datasheet was correct...



I'm pasting here part of the main code that I used:

INCLUDE "cdc_desc.bas"
INCLUDE "EEPROM_detect.pbp"

'*******************************************************
'Init the interrupt handling system
'*******************************************************
INCLUDE "DT_INTS-18.bas"     ; Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ; Include if using PBP interrupts

ASM
INT_LIST  macro     ; IntSource,          Label,  Type, ResetFlag?
        INT_Handler     USB_INT,  _DoUSBSERVICE,   PBP,  yes
        INT_Handler     TMR1_INT,   _TempCheck,   PBP,  Yes
        INT_Handler     INT0_INT,   _USBAttached,   PBP,  Yes
    endm
    INT_CREATE ; Creates the Low Priority interrupt processor
ENDASM

INCLUDE "USB_ASM_Service.pbp"