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joy19861111
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Post subject: PIC18F4550 USB AND EUSART  Posted: Mon Dec 20, 2010 3:20 pm |
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Joined: Sat Jun 12, 2010 3:50 am
Posts: 35
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can the USB and USART modules run at the same time??? because i read the datasheet that these 2 modules share the PORTC
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Simon Inns
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Mon Dec 20, 2010 5:09 pm |
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Joined: Thu Apr 01, 2010 6:23 am
Posts: 893
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They share the port but not the same pins. You can happily build a USB to serial converter using a PIC18F4550 or 2550. In fact there is even demo code, look for the CDC demo.
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joy19861111
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Wed Dec 22, 2010 3:37 pm |
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Joined: Sat Jun 12, 2010 3:50 am
Posts: 35
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joy19861111
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Thu Dec 23, 2010 4:07 pm |
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Joined: Sat Jun 12, 2010 3:50 am
Posts: 35
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do u hv face the problem that obtained the undesired result such as in the program PORTB is declared as output, PORTB = 0b11111111, however, the LEDs light out with 0b11011111. I checked the connections for the LEDs there is no problem and i checked the PIC PORTB pin is 0b11011111. What going on to PIC?? is it the PIC is faulted?? or the intialize for PORTB is not complete?
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Simon Inns
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Thu Dec 23, 2010 7:22 pm |
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Joined: Thu Apr 01, 2010 6:23 am
Posts: 893
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Hi
Make sure your TRISB settings are right and that you have disabled the analogue ports. It's usually one or the other.
/Simon
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joy19861111
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Sat Dec 25, 2010 2:47 am |
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Joined: Sat Jun 12, 2010 3:50 am
Posts: 35
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mr simon, may u briefly explain how to config the PLL?
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Simon Inns
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Sat Dec 25, 2010 9:08 am |
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Joined: Thu Apr 01, 2010 6:23 am
Posts: 893
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That's hard to do since I don't know the chip you are using or the type of external clock; however you will find that it is well explained in the datasheet for your device.
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joy19861111
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Sat Dec 25, 2010 11:13 am |
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Joined: Sat Jun 12, 2010 3:50 am
Posts: 35
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the one u posted the open source USB HID generic PIC18F version 2.0.0.0., the PLL config for the PIC18F u boost it to 48Mhz. So the overall PIC18F frequency is 48Mhz or these 48Mhz only for the USB module only??
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Simon Inns
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Sat Dec 25, 2010 2:16 pm |
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Joined: Thu Apr 01, 2010 6:23 am
Posts: 893
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It's 48 Mhz for the overall Fosc so the PIC runs at that speed.
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joy19861111
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Post subject: Re: PIC18F4550 USB AND EUSART Posted: Sat Dec 25, 2010 3:18 pm |
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Joined: Sat Jun 12, 2010 3:50 am
Posts: 35
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