Junk drawer phone as a music streaming server | Hacker News Reader

Junk drawer phone as a music streaming server

davidhampgonsalves.com

192 pointscarride79 comments

The killer app for Android is scrcpy.

This project can enable so many interesting things. It allows you to fully control, stream and automate anything running android including phones, Chromecasts, and even the android subsystem on Chromebooks.

The new version supports streaming audio in addition to the device screen from wherever you run the scrcpy CLI. You can even send keystrokes and "dpad" events to control apps, or connect your mouse and keyboard to the device like it was hardwired.

And it all works over your LAN via Ethernet or WiFi without root.

You could easily use this with any audio app to kick off casting to other devices in this context.

Oh and btw it even can run from inside a docker container. Cheers to the author(s) it's a hackers dream tool.

Thanks for this pointer.

For a long time I thought there should be a good open-source project that allows some usage of old phones that fall out of daily usage but still have most of the features working -- except for may be battery life or a chipped screen.

For example I have a bunch of tablets and mobile phones that are in this state.

Ideally I would like to be able to mount them to a wall and convert them into simple displays that I can "cast" a screen or video to (other use cases -- simple weather displays, security camera monitors, remote switches for smart devices, etc). I know some of these use cases are possible but last time I played with them it was a little more effort than I had time for. Was hoping to see more general purpose plug-and-play solutions emerge.

I just replaced an ancient cheap tablet that was displaying a weather app 24/7 with a more modern cast-off phone doing something similar (but that nice old app is no longer available..!)

What nice old app do you mean? A weather app?

So this is the comment that inspired the scrcpy post that is currently on the front page :D

https://news.ycombinator.com/item?id=35749366

Old routers can be repurposed too, with the added advantage that they can be flashed with a completely native OS such as OpenWRT and its huge number of available FOSS packages. https://openwrt.org/packages/table_owrt21_2/start The supported hardware list is quite long; chances are that many of us have in a drawer something that could run it. https://openwrt.org/toh/views/toh_fwdownload

Isn't it an inherent problem with phones that if they are left on charge forever that their battery will explode? I've had test devices that I left connected for months together and inevitably the battery has exploded on every single one of them.

Perhaps, it can be hooked up to a smart plug and charged up whenever battery goes down below a certain percentage and shut it off when it's full.

Becoming a spicy pillow is the inevitable fate of almost all small lithium electronics batteries. Keeping them in the 60-80% range will slightly help extend life, but that's about it, unfortunately.

I've been using "al dente" on my new laptop to keep the battery charge maxed out at 80% and hopefully extend the life of my battery.

If you have root, that's easy to do on Android as well. Honestly, it's one of the like three things that I root for these days

Thanks, didn't realize I could do that

My Samsung has this option, it's called Protect Battery, but I still need to turn it off to get through flights and other fun events.

Thank you. I've never heard of this option, I just enabled it.

For anyone who's interested, it's written as AlDente, one word:

Free version: https://github.com/davidwernhart/AlDente-Charge-Limiter

Pro version: https://apphousekitchen.com/

> spicy pillow

British English speaker here. I've not come across that expression before. The "pillow" part seems obvious, but not "spicy". What am I missing?

https://www.reddit.com/r/spicypillows/

Thanks. I suspect my brain is just too old to ever grok meme formation.

Battery fires are a genuine danger if a lithium ion battery at a high state of charge suffers physical damage.

https://www.youtube.com/watch?v=jGUkKi7cfK4#t=2m36s

Do a lot of phones have faulty charge termination circuits or something? I can't see any logical reason for this. Plenty of people leave laptops plugged in constantly for months without that happening.

I have a 2011 Macbook Pro that I have left on a charger for 5 years with no issue. Only runs for about 40-50 minutes off the charger nowadays.

That’s basically what I did for a android tablet mounted to a wall for home assistant control panel. Had a shelly smart plug that could be controlled via a simple http get request. I used tasker to monitor the charge state. When it reached specific state value, it would then make an http request to the shelly plug to turn off. Same when battery level dropped below a certain percentage.

That's actually a really clever hack.

Just watch out for battery degradation, at some point the % shown will not mean anything.

Even at 100% the battery won't be able to give enough power to even stay ON unless plugged in all the time. This is why we need removable and easily replaceable batteries as most devices are 2-3 years of regular use will have a degraded battery.

Yes - you're absolutely right. Eventually I'm going to see degradation in capacity. Fortunately, the tablet is a Amazon fire 10 tablet (rooted) and relatively cheap to replace. I paid $100 for it 3 years ago.

> Isn't it an inherent problem with phones that if they are left on charge forever that their battery will explode?

Not necessarily, it depends on how much care went into making the phone.

Ever since Samsung had the unfortunate experience of having every airline announce that their phone wasn’t allowed on board (even when switched off), battery management has received as much attention as is possible. Most implementations today have multiple fail safes in place to prevent the chances of a battery exploding.

Today, several extremely improbable events must happen in a row to make a battery explode from just being connected to a charger 24x7.

Source: Implemented battery charging on a different Lithium Ion battery bearing consumer product.

dont forget that Samsung followed that up with batteries that swelled while just sitting on a shelf as well.

https://youtu.be/OfM0GqsIB6c

Yeah, this is a concern for me too. I'd be more comfortable if I could replace the batteries in repurposed Android devices with a dummy passthrough that pulls power straight from USB-C.

If you don't need the "UPS" capability, you should be able to run them without a battery.

Not necessarily; laying aside the issue of whether the battery is even removable, a lot of devices expect to be able to lean on the battery for temporary spikes in power consumption. I don't specifically know that this affects phones, but I'd be surprised if it didn't

yes, and typically at the very least a protection circuit that needs to be implemented or faked, or whatever.

i replaced a swollen battery on a cheapo hotspot with an 18650, but i had to remove the protection chip from the old battery and wire that up with my battery holder. if i was more industrious/desperate i probably could have used the one in the 18650, but that was more fiddling than i wanted

Some phones refuse to boot without a battery. It was the case for my Lenovo P2.

The PinePhone boots without a battery but it's modem won't.

one way to defeat this problem is to connect the charger to a timer plug so that the charger can turn off at night. I use this approach to keep some lesser-used laptops connected and charged (edited) without so far running into the spicy pillow problem.

can laptop batteries explode as well in that condition? I have an old lenovo running ubuntu 24/7.

I and an acquaintance got identical Onn i3/4gb laptops (clearanced for 100usd). They left theirs plugged in constantly while I used the mechanism above. Three months later, theirs was suffering from spicy pillow, bad enough to rip the screw holders for the case, while mine is ok so far. I think the mechanism above is reasonable for shady hardware like the Onn laptop but I hope your Lenovo might do better.

If fits plugged in and running 24/7 and is old enough most laptops can run without a battery.

Lenovo's tablets are designed to be aware of this - after they've been plugged in for extra long (afaik 24H) they switch to battery-protector mode where they hover from 40%-60%. Hopefully somebody could steal this feature and add it to LineageOS or something. Edit: apparently you can do this on stock android with root[1]

[1]https://f-droid.org/en/packages/mattecarra.accapp/

There is BatteryBot Pro on https://f-droid.org where can set an alarm for charging the phone you use till 80%.

My old Nexus One has been serving me as an alarm clock for over 10 years now and it hasn't exploded yet.

Didn't they have removable batteries? One of my old nexi did at least.

The dative plural of nexus is nexui (and the nominative plural is nexus, with long u) :)

Nobody expects the fourth declension.

For fully stationary use, you could replace the battery with a voltage regulator + supercap combo like in this video: https://youtu.be/YfvTjQ9MCwY?t=856

This ensures that the phone does not get confused when powered straight from the adapter with the battery removed (provided it is even possible to do so).

I've not used these myself but they seem to be designed to solve this problem:

https://chargie.org/

This right here is Android's killer app, and the very reason I've exclusively owned rootable Android mobile devices (Nexus → OnePlus → Pixel) for a little over a decade. Every single one of my old devices that isn't lost or totally destroyed (a few have broken screens) is now a server providing little services like this one (mostly filehosting and backups in my case). It's been quite fun!

> This right here is Android's killer app

Similarly, for me, android's killer app is that I can still get a phone with an SD card slot and an aux jack - so my music is with me, without needing to rely on a flakey old phone rightly condemned to the junk drawer.

Which phone is that? Even Samsung (who once mocked Apple for it) has dropped those external features.

ASUS still has sdcard slots in their phones. Sony phones too but Asus is a better bet at this point for long term supportability.

All the Moto phones I have had come with these. I still see them in plenty of Android phones.

Yes, my previous phone was a Samsung, and I dropped them because they no longer come with these two features. My current phone is a OnePlus (basically rebadged Oppo). I also considered the Moto G series, but their selection in Canada is awful.

Sony Xperias still have SD card slots, although some of them don't have 3.5 mm jacks.

Samsung XCover Pro?

I'm using a Samsung Note 10 Lite. Wacom stylus, SD card, headphone jack, and though the battery is ostensibly not user replaceable, a guitar pick will open the case. I love this phone.

Trying to charge it revealed that the charging port was broken. I didn’t want to dig too deeply into the device but I got lucky and was given another S7 with a bad battery

Could've taped a dollar store qi puck to the back of it.

Thus I transcoded everything to mp3 at a lower bitrate that was still acceptable to my ears.

Somebody please tell me under what circumstances listening to low bit rate mp3 is better than dropping fifteen bucks on a 256GB microsd card. That is pants on head crazy.

It goes along with trying to repurpose a phone as a server: not much money, use what you've got.

Or a desire to never throw things out

I can't tell whether you see this as a bad hoarder practice, or as taking good care of available resources instead of newly producing something you didn't reasonably need (within reason, otherwise it's indeed hoarder)

> That is pants on head ... entertaining

I love these quirky working too hard for an iota of questionable gains. It warms my heart and soothes my soul. IMHO this kind of behaviour is going to be our saving grace when the aliens come and see if we're fit to join the galactic community. :P

Re-encoded low bitrate MP3, even...

> under what circumstances listening to low bit rate mp3 is better

when you are 40 and over and can no longer hear high notes

Years back when I was about 30 - I was convinced that I could tell between a 128Kbit OGG file and FLAC file. Re-encoding the FLAC's to OGG and mixing them up blindly... nope couldn't tell at all!

Nowadays I don't think I would even notice until it gets laughably bad.

Modern codecs and presets are great. Things what were encoded 20 years ago... ain't.

That’s an exaggeration but even so MP3 distortion isn’t a low-pass filter. There’s one specific problem with it encoding sounds like cymbals but that’s not a function of bitrate.

The sad irony here is that using a format which hasn’t been obsolete for a couple decades would have had better audio at a lower bitrate.

Where are you getting (true) 256GB microSD for $15?

not quite $15, but Amazon US seems to have PNY cards with fairly promising reviews for $16.99 at the moment (although they may be out of stock)

> Amazon

"We comingle fake and real products and have blatant fraud" Amazon? I would never buy SD cards or flash drives there if I had any other option. There's a reason the comment you're replying to said a "true" card of that size, and most of the reason is Amazon listings for fake cards.

pny is the only brand of sd that has failed for me, turning read-only after a short period of time. they are now on my vendor blacklist.

Actually, failing read-only is a feature that I would like. Most cards fail write-only ))

I've used this place, happy to recommend- https://bulkmemorycards.com/shop/microsd-cards/microsd-class...

Kind of a side-comment, but Termux is possibly my favorite app, and is one of the killer features of Android IMHO.

Similar here, though I use a different app (which requires root) to achieve roughly the same thing. I would not want to be without it and is one of the killer things that makes a phone so powerful nowadays.

It's really sad that Google doesn't give a rat's ass about it and these nice things tend to break with every version (see also: OsmAnd track recording as alternative for Google Location History keeps being killed and needs a different workaround in every second version since Android 4 or so). Termux is being all lovey dovey towards them in the FAQ https://wiki.termux.com/wiki/FAQ#Will_Termux_work_on_Android... (showing Google they're oh-so-reasonable and willing to play ball and provide good publicity) but much as they cover it up with pink ribbons, the FAQ still says: "we chose to force use compatibility with Android 9 APIs (SDK 28) at the cost of ability to publish updates on Google Play." (sounds like they've volunteered to be banned from publishing updates on the Play Store) and "[on Android 12,] spawning several processes would randomly close the application". So as I understand it, it's broken on anything newer than Android 9, but many use-cases still work until reality starts to catch up and it's removed from the Play Store for being stale or when newer Android versions decide that newer-than-9 security practices now become enforced. I dread getting a new phone with a new Android version... every time it's a struggle to get things back in order (e.g. automated backups of all your data, as imo everyone should (be able to) have, but you can't do that without rooting and knowing where to even find your /data).

There might be something wrong with your device if it kept closing Termux due to RAM.

Up until 1 month ago, I used my Galaxy S7 as my phone and I ran navidrome inside Linux (AnLinux) inside Termux and it didn't close automatically.

I now do the same with a Galaxy S10e as the already semi-broken S7 decided to call it quits.

This is great. Something that always upset me is seeing people spend huge amounts of money building IoT products when an old phone would be better and cheaper. The waste is especially galling when it is done by a company that makes its money off ads, and is selling fresh consumer electronics at a loss. Recycling your old phone gives a better experience and save money for both the consumer and the producer.

What’s the power situation on old devices like these? Is it not really a big deal because you’re not running heavy workloads or would say a NUC pay for itself in comparison?

NUC is hundreds of dollars. assuming this device runs like 5W on average, that'd be like $1 / year at $0.025/kWh in energy costs.

Not that it changes your fundamental point, but isn’t the typical energy cost 5x that rate?

Or 17.5€ at 0.4€/kWh for me.

Here are my research notes:

NUC7i7BNH

- 10.31 Watt Idle/49.31 Watt load

- $0.86/month idle to $4.32/month load

Intel Iris Plus Graphics 650

MacMini M1

- 6.8W idle/39W max (apple specs)

- 4.2W idle/31W load (anandtech compute MT workload)

Beats a low-end VPS in everything except existing in good network infrastructure. Android smartphone wasn't on my comparison list at the time, as I'm not familiar with installing and running debian on one.

Samsung Galaxy S7 -- supports wireless charging. So you can still get full functionality out of the phone if the physical charging port is the only one that is broken.

What’s the state of the art on whole home streaming these days?

Amazon seems to be intent on making echo dots less and less useful for that.

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