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alecms
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| bootloading via USB |
 Posted: Mon Oct 24, 2005 4:10 pm |
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Hello,
Has anyone been able to bootload code to a PIC 18f4550 through the chips internal USB transceiver? If so, I would be very greatful if you could please give me an overview of how this is done.
Thanks,
Alec |
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asmallri
Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia
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| Posted: Mon Oct 24, 2005 6:39 pm |
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Microchip have a bootloader for this chip on their site under USB solutions. Have you had a look at that one.
_________________
Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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alecms
Guest
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| Posted: Mon Oct 24, 2005 10:29 pm |
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| Thanks for the info. I looked at this but it seems as though this bootloader prevents one from using the USB port for anything besides updating firmware. I wonder if there are any more flexible solutions out there. |
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asmallri
Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia
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| Posted: Mon Oct 24, 2005 11:10 pm |
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Well if you need it to do something else then you are not really looking for a bootloader. Once the bootloader has loaded a program it passes control to the user program and it can do what it likes with the USB port.
_________________
Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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alec
Joined: 12 Oct 2005
Posts: 7
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| Posted: Tue Oct 25, 2005 3:20 am |
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| Have you been able to make this work? I suspect the difficulty would lie on the PC side. I don't see how you would switch from the dedicated bootloader USB driver provided by Microchip to another driver while the device is plugged in. |
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asmallri
Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia
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| Posted: Tue Oct 25, 2005 6:10 am |
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| alec wrote: | | Have you been able to make this work? I suspect the difficulty would lie on the PC side. I don't see how you would switch from the dedicated bootloader USB driver provided by Microchip to another driver while the device is plugged in. |
I have not tried Microchip's implementation but cannot see a problem. It enumerates initialise as device X for the bootloading process, then at the end of the bootloading process it disconnects from the bus (optional) then reconnects and enumerates as a totally different device.
_________________
Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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alec
Joined: 12 Oct 2005
Posts: 7
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| Posted: Tue Oct 25, 2005 11:54 am |
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Thank for your help.
Alec |
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