Rockbox Player - Project to design and build a Free/Open hardware audio player

[squarefoot]

The main problem is RAM size. Rockbox needs more then 2MB of ram (I'd say 4 is bare minimum). Ah, and porting to new architecture (Xtensa) is *a lot of* work.

Ouch... Very true about the different architectures, also I didn't realize so much ram was required; this leaves out most cheap low power boards unfortunately; there are some ARM Linux oriented boards that would be more than capable of running Rockbox, though I think they would draw too much power to be considered for a portable player. I played a bit with Orange/Nano PI boards, they're cheap and fun and CPU speed throttling seems to work well under Linux, but I have no idea on how much work would be needed to port Rockbox as a OS-less app to them whilst maintaining enough power management to keep the device portable.
This one for example is ridiculously cheap: http://www.friendlyarm.com/index.php?route=product/product&path=69&product_id=197

[Bilgus]

I too have toyed around with building a RB capable player.

Unfortunately, it is really hard to compete with economies of scale.
Even at the $8 price tag for that board you are forgetting about
all the ancillary devices that are needed.
Off the top of my head..
Screen, DAC, amplifier, battery, charging circuit, buttons, case, and whatever else I might have forgotten.

IMO in then end you are probably better off buying a ready made solution.

[majianjia]

I too have toyed around with building a RB capable player.

Unfortunately, it is really hard to compete with economies of scale.
Even at the $8 price tag for that board you are forgetting about
all the ancillary devices that are needed.
Off the top of my head..
Screen, DAC, amplifier, battery, charging circuit, buttons, case, and whatever else I might have forgotten.

IMO in then end you are probably better off buying a ready made solution.

THis dates from a year ago. Has any work being done at all here? I could quickly do some quick PCBa design around it.

I don't think so.  I don't even recall seeing anyone use Cortex M processors for a portable audio player yet.

It is true, building from zero is time-wasting.
But the reason I registered on RB Forum a few years ago and now i am checking this thread is I actually built one of this music player (please see the attaches).
This portable player was built about 4 years ago when I was a univ student who couldnt afford a HIFI player. The core is Cortex-M4F (STM32F4) which i dont think RB has the porting. I am glad if anyone can prove me wrong here.
The most difficult and time-wasting part for me is to program the GUI. I am a "MCU" guy; I can possiblly do everything from layout to mechanics but very poor on GUI programming.

For your interests:
 - 168MHz Cortex M4F
 - 128k RAM + 64k CCM RAM for MP3, FLAC and APE codec.
 - 1M on-chip flash
 - DAC: PCM1792
 -  Power supply: +- 6.5V for amplifiers.
 - Independent clock source
 - 8M flash for Chinese Font.
 - QVGA screen.
 - 3500mAh BAT for 10 hour replay.
 -  ~300g/~120*38*68mm

Currently supports: WAV to 192k 32bit, MP3, FLAC to 96k 24bit, APE 44k 16bit.
Adding codec isnt very difficult. I didnt do it just because i dont need them.
I had been using WAV alone for about 2 years before I addedd other codecs.

It is running with a very old version of RT-Thread,  and it's deprecated RT-GUI.

Since it is old, I am looking to built a new one and maybe an fully open source one (including hardwares, and mechanical parts). 
I might use a cpu that RB has already been ported on, like Rockchip's CPU, and a case that printed by 3D-printer instead of the aluminum case.

If there is porting already for Cortex M, i will be happy to use Cortex M.
The RAM size and flash size isnt a problem on cortex M4/7. Some of chips can run codes on external QPI-Flash, most of them support external RAM.
From my point of view, a Cortex M4/7 is more than enough to run RB.
Sorry for my English.

[coacharnold]

OMG ... thats REALLY cool ....   I'm not on the code developers side of things here .... but I'll vote for this .... especially since RB seems to have been slowing down the last couple years.... How much did that cost to build? 


COUNT ME IN

T

[uhmgawa]

If I were looking for a solution to this in the year 2018, I'd use a Raspberry PI Zero W:

1Ghz ARMv6
512MB DRAM
micro SD, WiFi, BT, uart, gpio, i2c, i2s, SPI
usb host, usb OTG, ...
US$5 at Microcenter (currently price, appears to be a perpetual promotion).

The issues are:

1. building a daughter board to supply display, input controls, i2s audio, voltage regulation and battery maintenance
2. deciding upon a strategy for intake of audio data.

For #2, a minimalist approach would require a usage-friendly method to share the microSD card
between system and music data.  Or USB host could be the data intake method.  Or a second
microSD on the daughter card (overkill).  Or forget about flash and just pull in whatever is needed
via wireless.

Slight modifications could produce an automotive in-dash version.

Could be a fun project if you really want/need a standalone music appliance in 2018+.

[coacharnold]

Yeah ... super cool ...  did Rockbox ever get a linux port that could easily be put on the Zero? ...   SOmebody must be doing some sort of battery for the zero...  that said ...  the LCD's a compatible across all the Pies right?

[coacharnold]

ok so this for power

https://www.adafruit.com/product/3196

then a touch PI LCD should work right? 

Then put firmware on SD card and have a media folder?

[saratoga]

Yeah ... super cool ...  did Rockbox ever get a linux port that could easily be put on the Zero?

There is an SDL port which runs on various Linux devices.

[coacharnold]

Will ir run on a Ras Pi ...  and then ...  will it communicate with he touch screen or does it need button inputs to be written into the code?   also ... perhaps utilize the pi-drive hard drive?... this doesn't sound so difficult

[majianjia]

If I were looking for a solution to this in the year 2018, I'd use a Raspberry PI Zero W:

since RPI is running Linux, it should be no problem to use Linux porting. I knew RB by running it on my Motorola E680G, an old Linux based smartphone.
For RPI 0 there is some points that might need to be considered.
 - Screen might be a problem.
 - ower comsuption
 - Sound quality

[coacharnold]

So,  I use RasPis with various DACs ... to pretty good results. in my home . For 20$  I just got what turned out to be a really good one from an ASIAN knock off group who are cloning the hifi berry stuff  ...

but just found this ... even better

https://www.adafruit.com/product/3016

[coacharnold]

Ok .. so also .... just found this

https://www.aliexpress.com/item/UGEEK-ZPOD-High-quality-lossless-HiFi-music-player-192k-24bit-Build-w-Raspberry-Pi-Zero-Portable/32790282017.html

[uhmgawa]

For RPI 0 there is some points that might need to be considered.
 - Screen might be a problem.
 - ower comsuption
 - Sound quality

A RBPi0 is already a pre-packaged generic board so I wouldn't add more generic off-the-shelf stuff to the solution.
Eg, the mini HDMI connector isn't doing anything for you and if a custom board were designed for an audio player
device, it would be the first component to get the boot along with support circuitry.  But we can work with the Zero
given its diminutive size.  So whatever is added should be a custom solution and address the above concerns.
I'd use a popular cell phone Li-poly battery, a form-appropriate lcd, and design around those physical restrictions
as the remaining components are far more flexible.

Assuming a linux host, there are many knobs for power consumption reduction.  Sound quality shouldn't be an
issue using an I2S codec.  So I don't see any insurmountable issues.

Ok .. so also .... just found this

https://www.aliexpress.com/item/UGEEK-ZPOD-High-quality-lossless-HiFi-music-player-192k-24bit-Build-w-Raspberry-Pi-Zero-Portable/32790282017.html

Unclear if that is a repackaging for a Zero or a PI-2 as that blurb refers to both.  Physically it appears to be a
PI-2 brick and probably somewhat clumsy to carry around.  Also more unneeded crap gets drug in such as 4x
USB host ports and a full HDMI connector.  Also the 100-mil connector comes soldered in which complicates
optimizing out the bulk introduced by that component.  Also a quad core 1GHz processor is beyond overkill for
the task.  So is the Zero's single core 1GHz which could likely be dropped by an order of magnitude during
most stream decoding operations.

[coacharnold]

sure just looking for stuff off the shelf that we can use to get this going ..... like

https://shop.pimoroni.com/products/lipo-shim

[saratoga]

Will ir run on a Ras Pi ...  and then ...  will it communicate with he touch screen or does it need button inputs to be written into the code?   

Assuming you can get the touchscreen to work with SDL+linux, yes you could, although remember Rockbox has only very crude support for touch screen devices (it is made for physical buttons).  You will need to implement button mapping and other things (e.g. if you add buttons what they do).