• Status Closed
  • Percent Complete
  • Task Type Bugs
  • Category
  • Assigned To No-one
  • Operating System
  • Severity Low
  • Priority Very Low
  • Reported Version Release 2.2
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by Anonymous Submitter - 2004-12-20
Last edited by bagder - 2005-03-09

FS#2415 - Rockbox will switch between USB and Play modes

Device: FMR.

Rockbox will switch between USB and Play modes, this
happens on all power sources:
1. USB (as expected)
2. Power adapter
3. Battery

When using a battery (and not connected to the USB
port), the device MIGHT startup on playback mode,
though rarely.

On some cases, the device will switch betweens modes
again and again.

I have no idea if this matter has to do with the software
or not, I understand that there is a good chance this is
a pure hardware matter - but you guys are the masters.


Closed by  bagder
2005-03-09 10:43
Reason for closing:  Out of Date
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407

Logged In: YES

This report is very old and concerns a Rockbox version from eons ago.

Lots happen in the Rockbox all the time, and if you still have
problems with this matter I suggest you file a new entry.

Project Manager

The obvious question is of course:

How does it behave when you run the original firmware?

shaig commented on 2004-12-21 01:32

Well, a very basic question indeed.

A few more facts:
1. I have Rockbox 2.2 flashed.
2. After messing arround with it, I did manage to reproduce
the problem when booting up with the original Archos
3. The USB mode appears to always be the Rockbox one - as
I am not familiar with the details, I assume this behevior is by

As I am not new to hardware and software development, I'd
be greatful if you could provide your insight on the matter:
How is the software triggeres to change modes? (It looks like
disk access/tiny voltage changes, trigger the problem)
Has anyone else had a similare issue?

Thanks again,

Project Manager

It sure sounds like a hardware problem. Maybe some ground
soldering joints are loose, or your battery doesn't connect
properly inside.

shaig commented on 2004-12-21 13:11

A good chance indeed, though I am rather corious about the
way the software gets triggered to switch the mode:
usb/play (interrupt/polling, is the decision done by software
or hardware).

I am sorry for the hassle and appriciate the response,
I also don't mind looking at the source code myself if you
could direct me to the coresponding file name. I assume this
is an interrupt based mechanism.

Project Manager

Surprisingly enough, the usb detection is in usb.c, you
would want to look at the usb_detect() function.

The USB mode is detected by reading an analog input (AN1).
It is normally 3V (0x3ff), and Rockbox decides that it
should enter USB mode if it goes below 1.5V. On a normal,
working FM/V2 recorder it goes close to 0V when the USB is

You could perform an experiment for me:

Go to Menu→Info→Debug→View I/O ports and give me all ANx
readings, with and without USB inserted. The USB mode isn't
detected when in the debug mode, so it's safe to insert the
cable .

shaig commented on 2004-12-21 14:04

Naturally, the fictive USB mode won't repeat (though I see
the power cord icon appear when not in debug).

No cable:
AN0: 0x3FE(-F), AN4: 0x009(-A),
AN1: 0x3FC(-F), AN5: 0x003(-5),
AN2: 0x003(-5), AN6: 0x1AB(-C),
AN3: 0x3FF(–), AN7: 0x000(-3),
Batt: 3.44(-46)V

With cable:
AN0: 0x3FF(–), AN4: 0x009(-A),
AN1: 0x010(-0F), AN5: 0x003(-4),
AN2: 0x000(-3), AN6: 0x1DE(-E1),
AN3: 0x3FF(–), AN7: 0x1D0(-3),
Batt: 3.92V (slowly rising as being charged)

I suspect that this info does not give the full picture, disk
usage is not simulated this way and does have an effect.

BTW, How many reads trigger the change? Is one low AN1
read enough to for Rockbox to switch?

Project Manager

This report is very old and concerns a Rockbox version from eons ago.

Lots happen in the Rockbox all the time, and if you still have
problems with this matter I suggest you file a new entry.


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