MikroElektronika Forum

Im using the given circuit design in MikroC to communicate with PC using USB. But it doesn't work correctly. PC doesn't identify it. I'm using 20 Mhz oscillator instead of 8 Mhz....

Any Help .. ???

"Hello" .. "Please" ... "Thanks" ... never ?

if you want some help .. give us more details!

proUsb wrote:Im using the given circuit design in MikroC to communicate with PC using USB. But it doesn't work correctly. PC doesn't identify it. I'm using 20 Mhz oscillator instead of 8 Mhz....

Can you show us please the "Edit Project" (= configuration bits) values and the MCU speed in the "Project Settings" that you use?

so true


more details and learn how to say " Please" and " Thanks"!!!

phil31 wrote:"Hello" .. "Please" ... "Thanks" ... never ?

if you want some help .. give us more details!

I'm really sorry about that .. i was in a hurry so jst typed it.. pls apologise me.
Thank you all for your replies.

when I plug the USB connector to the PC it says device not recognised. I want to know some details about creating the usbdsc.h file too.

Thanks

Hi!

PC doesn't identify it. I'm using 20 Mhz oscillator instead of 8 Mhz....

When using the 20Mhz crystal you should set the 96MHz PLL Prescaler to 5.

I want to know some details about creating the usbdsc.h file too.

What exactly?
Also, I recommend the Jan Axelson's book "USB complete" as one of the best USB manuals ever.
http://www.lvr.com/usbc.htm

Best regards
Slavisa

Hi people,

I'm getting my first steps on USB lane and I'm having the same troubles as USBpro.
I've compiled two examples given on this forum and thy did not work any way.
The problem still the same: PC (windoes) does not recognize the microcontroller usb port.

Details:

MikroC 8.2 version
Microcontroller: PIC18F2550
HS Quarz freq: 12 M

Selected configuration words: (only values turned ON)
1L:
PLLDIV_3 -->To obtain 4MHz from 12MHz Quarz
USBDIV_2 ---> able to clock transceiver from 96MHz by 2

1H:
FOSC_HSPLL_HS
FCMEM_ON
IESO_ON

2L:
PWRT_OFF
BOR_ON_ACTIVE
BORV_43
VREGEN_ON

2H:
WDT_OFF

3H & 3L:
MCLRE_ON
LPT1OSC_OFF
PBARDEN_OFF
CCP2MX_OFF

4L:
STVREN_OFF
LVP_OFF
ICPRT_OFF
XINST_OFF
DEBUG_OFF

The other words remain as is.

And here is the code I´ve tried, taken from a "working" example in the forum and with some modifications done by me (basically on MCU ports configuration).
___________________________________________
#include "USB_New"

unsigned char Read_buffer[64];
unsigned char Write_buffer[64];
unsigned char num, Flags;

/* Timer interrupt service routine */

void interrupt()
{
HID_InterruptProc(); /* Keep alive */

}

/* Start of MAIN program */

void main()
{

/* Disable all interrupts */
INTCON = 0; /* Disable GIE, PEIE, TMR0IE,INT0IE,RBIE */
INTCON2 = 0xF5;
INTCON3 = 0xC0;
RCON.IPEN = 0; /* Disable Priority Levels on interrupts */
PIE1 = 0;
PIE2 = 0;
PIR1 = 0;
PIR2 = 0;


/* Ports Configuration */

PORTA=0;
ADCON0=0x0; /* A/D disconnected. */
CMCON =0x7;
ADCON1=0x0F; /* Port A is a Digital port */
TRISA=0; /*Port A as output */

PORTB=0;
TRISB=0x01; /* PB0 - EXT interruption IN. All the other pins programmed as outputs*/
//INTCON=0x90; /* GIE=1, PEIE=0, INT0IE=1*/
//INTCON2=0x80; /* All PB pull-up disable, INT0 ocurres on falling edge */

PORTC=0;
UCON.F3=1; /* RC4 and RC5 configured as DI and USB module was enabled */
UCFG.F3=0; /* On-chip USB transceiver was enabled */
TRISC=0x0; /* RC7..RC4 were configured as DI, the other pins as outputs */


Flags=0x03; /* Mute-Disabled, ZCross-Enabled */
PORTB.F7=1; /* Mute - Disable */
PORTB.F6=1; /* Zero Crossing - Enable */
PORTB.F5=1; /* CS signal - Disable */



Hid_Enable(&Read_buffer, &Write_buffer);
Delay_ms(250);
Delay_ms(250);

// Read from the USB port. Number of bytes read is in num


while(1)
{
num = Hid_Read();
if(num > 0){
if((Read_buffer[0] == 'P') && (Read_buffer[1] == '=') &&
(Read_buffer[2] == '?') && (Read_Buffer[3] == '?'))
{
PORTA.F0 = 0x01;
Write_buffer[0] = 'P'; Write_buffer[1] = '=';
Write_buffer[2] = 'T'; Write_buffer[3] = 'T';
Write_buffer[4] = 'A';Write_buffer[5] = 'R';
Hid_Write(&Write_buffer,6);
}
}
delay_ms(80);
PORTA.F0 = 0;
num = 0;

} //end while (1)
Hid_Disable();
}//end miain

¿Somebody could tell me what´s wrong here?

Also I want to ask for information about how the HID terminal works. Indeed on the MikroC 8.2 HELP nothing is written.

Thanks a lot,

Black Bird

Hi, there are several things not correct in the configuration file (a.o. the clock frequency, which should not be set to the crystal frequency but to the MCU clock speed), please have a look into:
http://users.edpnet.be/rosseel01/DRO/PI ... %20Old.htm to obtain the correct ones for use with an older mC version (as you do apparently).

Selected configuration words: (only values turned ON)
1L:
PLLDIV_3 -->To obtain 4MHz from 12MHz Quarz
USBDIV_2 ---> able to clock transceiver from 96MHz by 2

- CPUDIV_OSC1_PLL2 should also be checked (gives you an 48 Mhz CPU clock)

Hid_Enable(&Read_buffer, &Write_buffer);
Delay_ms(250);
Delay_ms(250);

Delay should be 2 times 1000 ms.

Furthermore: you use an old version of mC, the configuration settings screen is different from that one of the newest version.
For documentation on the newest version, see http://users.edpnet.be/rosseel01/DRO/PI ... _Clock.htm.

Good luck!

slavisa.zlatanovic wrote:Hi!

PC doesn't identify it. I'm using 20 Mhz oscillator instead of 8 Mhz....

When using the 20Mhz crystal you should set the 96MHz PLL Prescaler to 5.

config.JPG

I want to know some details about creating the usbdsc.h file too.

What exactly?
Also, I recommend the Jan Axelson's book "USB complete" as one of the best USB manuals ever.
http://www.lvr.com/usbc.htm

Best regards
Slavisa

USB voltage regulator disabled?