USB_P configuration in bootloader?

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USB_P configuration in bootloader?

(8 posts) (4 voices)

Started 3 years ago by nplayle
Latest reply from poslathian

nplayle
Member

Hi All,

I'm working on flashing a new bootloader to my take on a maple. In designing the board, I had to change the location of the USB_P input pin, but I can't find anywhere in the code for the bootloader that references the pin

http://dl.dropbox.com/u/20784782/IMU_MainProcessor.pdf

Anyways, here is the schematic, the USB_P pin was changed from PC11 to PB8. I flashed the Maple bootloader to the device successfully, and it loads the bootloader and stays in perpetual bootloader mode (based on the pulses out from PA5), but shows up as an unrecognised USB device, and I can't seem to install drivers for it. So, I'm wondering if the USB_P pin has something to do with it. I haven't modified anything from the bootloader yet, just looking. I'm planning on using the RET6 branch for modifications though.

Nick

Posted 3 years ago #
siy
Member

Hmm. There are no dependencies on this pin in bootloader. Mini does not have this network either. So, there must be something else. Usually it is quite simple to get MCU start flashing and flash bootloader. More complicated thing is to nail down problem when MCU does not appear on the USB at all. Usually this happens when some pin on MCU or USB socket is not soldered good enough. I'd suggest try to heat up every pin on MCU and USB-related circuit including socket.

Posted 3 years ago #
nplayle
Member

Hmm... I was hoping it was a USBP issue... I might try jumping that pin high to test and see if it does anything, otherwise break out more sophisticated methods. I just briefly checked the solder joints by visual inspecttion and they looked okay.

My laptop is running windows server 2008 R2 and it detects a device but doesnt know what it is, (Dev ID and manufacturer ID are both 0x0000) and won't let me install drivers. My desktop (also server 2k8r2) doesn't detect anything. My other laptop (server 2003) detects a device but same issues. I tried getting it into my virtual machine (ubuntu through vmware workstation) but it doesn't pick up the USB device since windows doesnt like it. Unfortunately, I don't have a pure XP or linux machine to test driver issues more closely. My regular maple connects to my laptop just fine.

I'll troubleshoot some more (likely Tuesday) to see if I can find the issue. Unfortunately, my logic analyser doesn't do USB so it might be a bit of a pain.

Also thanks for your help siy, your design inspired this setup. If all goes well (ie when all the kinks are worked out) I'm planning on open sourcing this design.

Posted 3 years ago #
ala42
Member

Did you check that you have voltage on pin 1 of the STF202 ?

Posted 3 years ago #
nplayle
Member

Yep, pin 1 is getting 5.11v according to my scope.

It looks as though DP is being pulled down occasionally by the USB host when plugged in intially, but DM remains constant at 0V.

Actually siy, you had mentioned that in certain cases you needed to invert the bootloader logic for DISC, is this one of the cases?

Posted 3 years ago #
siy
Member

No, this is not the case. Seems you have incorrectly connected STF202 and as a result you have DM and DP swapped at MCU. You can find correct connection for STF202 here: http://we.easyelectronics.ru/uploads/images/00/22/11/2011/12/27/d14b13.png

I guess you have tried to "mirror" connections for convenient routing (I'm not quite sure that this is correct, because internal circuit is not symmetric between inputs and outputs). For STF202 pins 2 and 5 form the D- pair and 3 and 4 - D+ pair of input and output pins. You have signal USBD_N connected to pin 4 instead of 5.

Posted 3 years ago #
nplayle
Member

Ah crap I see where I went wrong. It probably happened because I had to make that part myself and didn't pay close enough attention to the pin numbers.

I'll see about jumping them with wires to get it working in the time being. Hopefully I'll be able to get something working about it.

Posted 3 years ago #
poslathian
LeafLabs

USB-P isnt used now, but it *could* be used to detect in firmware when the board is being powered by USB/when USB is plugged in.

Posted 3 years ago #

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