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.

[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.