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by DaveB
Tue Jan 05, 2016 9:58 pm
Forum: Advanced users
Topic: Power Down Options (Mobile)
Replies: 3
Views: 886

Re: Power Down Options (Mobile)

I'd add that you also need a way to shut off the output of the charger when the PI shuts down, otherwise it will discharge the (LiPo) battery. This would need to happen as the last part of shutdown, after the filesystem has been re-mounted read only.
by DaveB
Mon Dec 28, 2015 11:35 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

From your description, it sounds like the host isn't detecting anything at all. If you use a Linux host do you get anything USB related in dmesg?

Also, I don't think that D+ and D- need to be crossed in your hacked up cable.
by DaveB
Mon Dec 28, 2015 7:19 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

How are you connecting the Pi to the host? I don't have one to try it out myself, but I think that the A and A+ models need a non-standard cable with a USB type A plug on both ends to use device mode.
by DaveB
Mon Dec 28, 2015 12:11 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

I'm getting confused, aren't we talking about two different things here? The USB device mode that the Pi boots into if no SD card is present is completely separate from USB device mode support under Linux. Even if you use the usbboot program you still need the dwc2 driver and the gadget driver loaded.
by DaveB
Thu Dec 24, 2015 11:11 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

Ladyada has posted a tutorial with pre-compiled kernel here. I'm not sure if this is dual mode or device only though.
by DaveB
Wed Dec 23, 2015 9:10 pm
Forum: General discussion
Topic: Raspberry and Busybox
Replies: 22
Views: 10437

Re: Raspberry and Busybox

If your aim is to build a very cut down Linux installation, then yes, you can use Busybox. I'd suggest investigating Buildroot as this will do most of the work of building the installation for you. There is a page on it here which is specific to the Raspberry Pi but a little out of date.
by DaveB
Wed Dec 23, 2015 4:11 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

I get the same error using gadget only mode. I think it's because there are no USB hosts present.
by DaveB
Wed Dec 23, 2015 10:30 am
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

I had exactly the same problem until I changed config.txt. There is something in the standard Raspbian one that causes it to hang but I've not worked out what it is yet.

Try replacing config.txt with one that just has this in it and nothing else:

Code: Select all

device_tree=bcm2708-rpi-b.dtb
by DaveB
Mon Dec 21, 2015 5:05 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

No, I can only get dwc2 to work in device mode if I compile it with the "Gadget only mode" option, regardless of which type of cable is connected. I'm replying to myself here, but I've tried dual mode again and got it to work this time. I must have made a mistake the first time I tried it. Anyway, ...
by DaveB
Mon Dec 21, 2015 4:00 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

Re: HOWTO: Enable USB device mode on Pi Zero

Does your kernel switch between client & host OK when plugging in an OTG adapter (I'm assuming you will see the old issues we had with USB in host mode, since fixed with the FIQ magic)? No, I can only get dwc2 to work in device mode if I compile it with the "Gadget only mode" option, regardless of ...
by DaveB
Mon Dec 21, 2015 2:33 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible? EDIT: Yes, it is!

I've written up how to enable device mode here. I thought that the advanced section was a better fit for it rather than continuing this thread in GD.
by DaveB
Mon Dec 21, 2015 2:29 pm
Forum: Advanced users
Topic: HOWTO: Enable USB device mode on Pi Zero
Replies: 68
Views: 47521

HOWTO: Enable USB device mode on Pi Zero

Firstly, many thanks to ED6E0F17, notro and others on github who worked this all out. The original thread is here . I am Dave-0 in that thread but I didn't do the clever bits. This is very new and a bit rough and ready so please chip in with corrections and improvements. Any mistakes are most likely...
by DaveB
Mon Dec 21, 2015 11:35 am
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible? [EDIT: Yes, it is

ejolson wrote:
DaveB wrote:I've done a quick test and got it to work as a serial gadget.
What about as a USB Ethernet gadget?
That should work but I've not tried it yet.
by DaveB
Sun Dec 20, 2015 7:40 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible? [EDIT: Yes, it is

This may be of use. https://github.com/raspberrypi/linux/issues/1212 It is! The people contributing to that thread (mainly ED6E0F17 and notro) have worked out a way to use the dwc2 driver to get device mode. I've done a quick test and got it to work as a serial gadget. I'll post some more details w...
by DaveB
Wed Dec 16, 2015 7:13 pm
Forum: Bare metal, Assembly language
Topic: Create USB CDC device?
Replies: 1
Views: 1073

Re: Create USB CDC device?

I've been asking about getting the Zero to operate in USB device mode (link here ) but under Linux, not bare metal. There has been an unconfirmed suggestion (see the link) that the foundation devs are working on it. I know it's not exactly what you're asking for, but if it can be made to work under ...
by DaveB
Mon Dec 14, 2015 10:03 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible?

This may be of use. https://github.com/raspberrypi/linux/issues/1212 Thanks, that's interesting. I've now tried plugging the Zero in with no SD card and a normal (non-OTG) USB cable plugged into the USB port. The host machine (Linux desktop) detects it as a USB device: dmesg: [ 6764.150505] usb 6-1...
by DaveB
Mon Dec 14, 2015 9:19 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible?

If this can be made to work - it would be great boost for headless working :) That was what I was thinking: use the Zero as a sort of super powerful Arduino. It would be great to be able to do this without needing a USB to serial converter which, for the Zero, would double the cost. I wish I knew m...
by DaveB
Mon Dec 14, 2015 8:32 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible?

I'm sorry that I can't help you any more, it's far beyond my knowledge, only ever having exploited (as a user) the USB client mode that teensy & mbed offer. Good luck with your endeavors. No worries, thanks for the pointer to the Pimoroni blog, at least I know the RPF devs are looking into this. It...
by DaveB
Sun Dec 13, 2015 10:23 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible?

As you note, with the advent of the zero this may be possible, and RPiF employee dom appeals here for help to get it working: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=127003&start=50#p850028 I've done a bit of tinkering with this now. If I revert this commit as suggested by dom in th...
by DaveB
Sun Dec 13, 2015 9:48 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

Re: USB device mode on Pi Zero - possible?

On the pimonori youtube video blog it was said recently they'd seen people @ RPiF working on it so fingers crossed. Sorry no link & I ain't watching it all again! Thanks, I didn't know that. I've found it now so here's a link for anyone else who's interested: https://youtu.be/_PNx3BXTTss?t=12m34s .
by DaveB
Sun Dec 13, 2015 6:50 pm
Forum: General discussion
Topic: USB device mode on Pi Zero - possible? EDIT: Yes, it is!
Replies: 18
Views: 5818

USB device mode on Pi Zero - possible? EDIT: Yes, it is!

I've been digging around on the forum for a couple of days now trying to find out if it is possible to get the Pi Zero to act as a USB device instead of a host under Linux. As far as I can tell, the Zero is capable of doing this at a hardware level but the dwc_otg driver doesn't work in device mode ...
by DaveB
Sat Nov 10, 2012 11:17 am
Forum: General discussion
Topic: Raspberry Pi T-shirt/Sweatshirt
Replies: 6
Views: 1672

Re: Raspberry Pi T-shirt/Sweatshirt

Have sent an email about it and I'll post again if I get any more info. Just got a response back - it seems like what's happened is that some orders have been set to "Shipped" when they should have been set to "Dispatched to Distributor", hence the confusion. And it turned up this morning - quite n...
by DaveB
Fri Nov 09, 2012 7:15 pm
Forum: General discussion
Topic: Raspberry Pi T-shirt/Sweatshirt
Replies: 6
Views: 1672

Re: Raspberry Pi T-shirt/Sweatshirt

DaveB wrote:Have sent an email about it and I'll post again if I get any more info.
Just got a response back - it seems like what's happened is that some orders have been set to "Shipped" when they should have been set to "Dispatched to Distributor", hence the confusion.
by DaveB
Fri Nov 09, 2012 6:41 pm
Forum: General discussion
Topic: Raspberry Pi T-shirt/Sweatshirt
Replies: 6
Views: 1672

Re: Raspberry Pi T-shirt/Sweatshirt

Look in the store (front page link or http://www.raspberrypi.com/ ) What's there is a trial run. More soon I would think Anyone received their t-shirt yet? Ordered on 01/11, got a "it's shipped" email on 02/11, still received nothing, even though they're quoting 24 hours shipping to delivery. Have ...
by DaveB
Thu Dec 15, 2011 10:38 pm
Forum: Other projects
Topic: How to add clock backed by battery?
Replies: 24
Views: 7783

Re: How to add clock backed by battery?

Quote from crundy on December 15, 2011, 22:10
Hmm, would this work then?

http://www.ebay.co.uk/itm/3-3V.....0762577188

It looks like it should do: I2C interface, runs at 3.3V and supported by Linux.

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