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pic18f4550, Full speed but usb 1.1 compatible?

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cozturk

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mikroc 18f4550 usb

I modified some sample projects (cdc demo, hid demo etc.) to compatible low speed. It was ok. no problem. The projects works fine as low speed mode.

Unfortunately, I have to use pic18f4550 as Full speed but usb 1.1 compatible. is it possible?

I believe that this is impossible for pic18f4550. if full speed needed, usb2.0 compatible port needed.

Any solution to correct this problem for pic18f4550?.

Some webcams etc. full speed but usb 1.1 compatible
 

M!k

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full speed usb

cozturk said:
...if full speed needed, usb2.0 compatible port needed.
Why this? USB 1.1 covers low speed and full speed, USB 2.0 additionally high speed devices. So USB 1.1 shoud satisfy your needs concerning a full speed device.


Mik
 

cozturk

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usb internal regulator pic18f4550

I thought for only pic 18f4550
"if full speed needed, usb2.0 compatible port needed."

Because of I tried modifiying config etc. accordig to *.inc
 

Andy_123

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low speed usb pic18f2455

I am using 18F4550 with USB1.1 port at full speed with CDC firmware - no problems.
Same board work on USB2.0 ports.
You don't need USB 2.0 to run full speed.
You need USB2.0 for high speed devices only.
 

Memphis

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what is the speed of usb2.0 and 1.1

As far as I know, there are some electrical difference between USB 1.1 and 2.0. As you can see, USB 2.0 also support Full speed and it's backward compitable with spec 1.1. Many companies usually say that they meet spec 2.0 even only support full speed...;)
 

hill

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pic18f4550 usb mikroc program

cozturk said:
I modified some sample projects (cdc demo, hid demo etc.) to compatible low speed. It was ok. no problem. The projects works fine as low speed mode.

Unfortunately, I have to use pic18f4550 as Full speed but usb 1.1 compatible. is it possible?

I believe that this is impossible for pic18f4550. if full speed needed, usb2.0 compatible port needed.

Any solution to correct this problem for pic18f4550?.

Some webcams etc. full speed but usb 1.1 compatible

As everybody here said, it has nothing to do with the USB version. Both v1.1 and v2.0 support full speed communication.

There are many reasons, that I think might caught you. Here the checklist:

1) Did you wire D+, D- line correctly? I have seen someone had the same problem as you described when D+ and D- lines are wired mistakenly.

2) Did you use internal pull-up? Then did you enable internal voltage regulator? Had a capacitor connected to VUSB pin? Again I have seen someone had this problem when the capacitor was missing.

Good luck.
 

    cozturk

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cozturk

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pic18f4550 webcam

Ok. capacitor to VUSB pin, solved this problem on my prototip board.

thank you.
 

rfkfun

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Re: pic18f4550, Full speed 12Mbps?How can I achieve?

Hi,
How did you achieve 12Mbps speed in PIC18f4550?I have implemented the USB serial protocol. But not not getting that speed. I am getting only 2k. What it is happening please reply.

Thanks.
 

vikky

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Hi cozturk

Can you pls tell me which capacitor u used.

Regards

Vikky.
 

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