Fuze and Griffin Dock line out

[Chronon]

The pages give pretty specific instructions.  Is there a particular spot where you got stuck?

[hynpin]

I would like to thank for the patch. It is working well. Also would like to say thanks for those guides. I have never did something like this, but with support like this it was pretty easy (even when my old laptop was preparing everything through rockboxdev.sh for about thirty hours  ). Once again thank you all!

[tenfoot]

I've put an updated version of this patch on the tracker at: http://www.rockbox.org/tracker/task/12074

Instead of using the max volume setting to enable the lineout, I've added a lineout setting - this can be added to the quickscreen so it's quite easy to switch between headphones and lineout.

I decided to change from the max volume setting as you get a loud burst when switching back to headphone mode before you can get back to a sane level.  Also I found I kept knocking it off lineout mode when changing tracks.

[bertrik]

From a technical point of view, I think we should use a system message to be picked up by the default event handler in apps/misc.c when a dock gets connected or disconnected. Something like either a SYS_DOCK_CONNECTION message, with an associated boolean data item that indicates connection or disconnection, or alternatively two messages (SYS_DOCK_CONNECTED and SYS_DOCK_DISCONNECTED). This is analogous to how we handle headphone detection and charger detection.
For the fuze v1, we could detect dock (dis)connection in the button handler interrupt.
After catching SYS_DOCK_CONNECTION could we could then poke the audio hardware to set the proper audio routing and set volumes appropriately through one or more audiohw_XXX calls.

[zenki]

Thanks for the update..
by the way I noticed from the last patch, that although this enables lineout in RB, the output volume to my amp is lower than the official FW.

Perhaps it's related to the volume scale of RB?
Anyway, the difference may be small but it makes me think the lineout from RB is not exactly the full output that the Fuze can handle..

[ardeeon]

with this kind of patches, is it safe to say that we will see Line-Out to be fully supported on fuze v2?

[moxill]

I just want to pass on a big up to tenfoot, you made me a very happy camper.  I can now hook my fuze up to my SET amp.  The sound from my sansa(s) is really clean, I can forget the usb dac for a while.

It took me a few minutes to find the LO setting:
Settings>General Settings>System>Line Out
And yes there is a little popping when toggling between on/off, so probs best not to do that live.
I made a DIY line out so I can fit both headphones and the LO cable at the same time.  I can confirm this patch shunts the headphone volume for those that were curious / concerned about battery life. 

Fuze/Clip + Yuin PK3 is still by far the cheapest ticket to audio nirvana, but now I can drive my Grados with my headphone amp using Rockbox in all its gapless glory.  This patch seals the deal, time to invest in a new fuze, the battery in mine is about cooked.

[esm]

Unfortunately, whatever pin it is, we apparently do not print it on the debug screen, so it'll take a bit more work for someone to find it. 

Hi. Rockbox newbie here. I just bought a Fuze v2 + Griffin iTrip car adapter, and discovered this problem. tenfoot's lineout patch helps, but not quite enough. I would like Rockbox to automatically detect, on powerup, that it is connected to a car adapter (not a USB host) and that it should 1) boot itself, not the original FW, and 2) enable lineout automatically.

Working with the source and the 1.13 revision of the AS3525 datasheet, I've instrumented debug-as3525.c to print what I thought were some likely candidates: ENRD0-2, some USB_[IO]EP[0-3]_{CTRL,STS}, GPIO[A-D]_IS and _MIS. No joy. ENRD0 flips from 0x00 to 0x28 when plugged in to the Griffin, as expected, but that's indistinguishable from computer USB.

Can anyone suggest other registers to monitor? Other things to try? I am highly motivated to fix this. Thanks in advance.

[saratoga]

Booting into the original firmware is actually by design since USB is very unstable in rockbox on your player.you can disable that by editing mkamsboot and flashing a new bootloader. Be careful though a bad flash will brick your player.

Regarding line out, I always thought it was detrctedbby one of the dbop in pins like the buttons and wheel on the first fuze.

[esm]

Booting into the original firmware is actually by design since USB is very unstable in rockbox on your player.

Understood. To clarify my earlier post, I don't necessarily want to boot in USB mass storage mode. I want Rockbox to detect the car adapter. I.e. "I sense USB (bit 3). Now: if connected to computer, boot into original FW (current behavior). If connected to car adapter, boot into Rockbox (music mode, not USB mode) and enable line out".

Regarding line out, I always thought it was detected by one of the dbop in pins

Will check those as soon as I have time. Thanks for the suggestion.

[saratoga]

Booting into the original firmware is actually by design since USB is very unstable in rockbox on your player.

Understood. To clarify my earlier post, I don't necessarily want to boot in USB mass storage mode. I want Rockbox to detect the car adapter.

I don't think its possible to detect if its a charger or USB at that point. We're basically just patching the sandisk bootloader, so we have no hope of getting the USB controller working and checking if anything is listening on the wire.   Once USB is working, this won't matter though, since we'll always boot into rockbox.  On the Fuze v1 car adapter mode works fine for this reason.

Regarding line out, I always thought it was detected by one of the dbop in pins

Will check those as soon as I have time. Thanks for the suggestion.

FWIW I don't remember if we have the fuzev2 setup to read from DBOP, but the fuze v1 does, so you could probably look at that.  ITs not the same processor, but fairly similar. 

[esm]

I don't think its possible to detect if its a charger or USB at that point. [...] we have no hope of getting the USB controller working and checking if anything is listening on the wire.

Oh. I interpret that as: the difference between the car adapter plug and the Fuze-to-computer plug is a protocol one, not a difference in the connectors themselves. Is that the case?

[saratoga]

I don't think its possible to detect if its a charger or USB at that point. [...] we have no hope of getting the USB controller working and checking if anything is listening on the wire.

Oh. I interpret that as: the difference between the car adapter plug and the Fuze-to-computer plug is a protocol one, not a difference in the connectors themselves. Is that the case?

I think all you have is a GPIO pin on the power supply line, and the USB controller.  So short of powering up the USB controller and checking to see if its errored out while connecting, theres no good way to figure out if a voltage on the power line is from a charger or an actual USB host.

(At least I'm pretty sure.  Its possible theres some way to get the usb controller or PMU ADC to measure an impedance or something across the USB data lines, but I don't recall seeing anything about that.  Even if there is you probably can't safely access them from within the sandisk bootloader)

[esm]

[...] So short of powering up the USB controller and checking to see if its errored out while connecting, theres no good way to figure out if a voltage on the power line is from a charger or an actual USB host.

Foo. Okay... sounds like I was on a wild-goose chase. Thank you for setting me straight. I'll read up on the USB patch thread, see if there's something I can test or help with there.

[saratoga]

[...] So short of powering up the USB controller and checking to see if its errored out while connecting, theres no good way to figure out if a voltage on the power line is from a charger or an actual USB host.

Foo. Okay... sounds like I was on a wild-goose chase. Thank you for setting me straight. I'll read up on the USB patch thread, see if there's something I can test or help with there.

If you just want to use that adapter, its probably enough to disable booting to the OF on USB insertion (you can still do it manually with the button key), and then apply that patch to force line out on all the time. 

That said if you're interested in figuring out how to autodetect line out, that would be great too.