tldr: Is there any available case that has integrated LEDs which can be activated by phone notifications and which fits the Fairphone 4? Or have you heard of anyone developing one or something similar?
My story:
After being very happy with my Samsung S9+ for over 4 years they decided to silently drop security updates and I was unlucky enough to get the American version with the unbreakable bootloader so here we are I always wanted to support phones made to last 5+ years so why not.
I am really happy with the FP 4 after I was able to get rid of a lot of the Android 11 annoyances. It feels good, is fast enough, long lasting enough, the camera is fine. Everything is cool for me. But then it hit me hard. No notification LED. After reading in this forum that, yep, itās like that, I was honestly already putting it inside the box again, ready to ship it back to return it in my 14 days because thatās an absolute dealbreaker. However, I thought it may be wise to look for alternative phones first I would get instead and it seems its an unholy misguided industry trend. All smartphones I would have gotten instead had no LED anymore. I tested all the apps to work around this, including using the flash but itās just not the same. To understand what I mean and get a very good idea of the use cases, just have a look at this case, which is unfortunately not available for FP4: Light Up Notification Case - YouTube
So I will keep the phone in the end because there is just no good alternative out there but does anybody know a case similar to the one in the video? Or any other gadget which I can connect via Bluetooth and which controls an LED? Iād even give it a go and try to solder it myself into a case. I canāt understand how anybody can be in a bar, a cinema or just see their mobile phone across the room and be honestly happy and content with a dark black mute block which keeps the secret if somebody was trying to contact its owner for itself.
How to connect? NFC?
It should be convenient so I donāt imagine any cables. I like the NFC idea because I donāt use it normally so it wouldnāt hurt me if an NFC antenna inside of a case would render it unusable for anything else. Seems this guy managed to put an LED inside of a tag but itās weird, maybe itās fake: NFC TAG/GLOW LED WITH NFC - YouTube Anecdotal evidence suggests a smartphone NFC provides a maximum of around 800 micro-Watts? Seems a typical SMD LED needs around 200 MILLI-Watts. Still the components seem low cost, maybe I try that. That could be neatly integrated in a Pop Socket Grip if the field is strong enough (lots of wishful thinking here).
The LED Phone Case is kinda cool.
Since I want to max out the time I have this phone Iāll definitely look into this case if other ideas fail. I could imagine doing something like that myself but I try to avoid using a LiPo battery in a DIY-project because I need to fly often professionally and could anticipate problems during the safety check. And also without knowing exactly where the battery is in that LED Anime case Iām not sure I want to cut into it. If there is some off-the-shelf solution that looks safe that could be ok but of course in the spirit of saving resources Iād be all for the most minimal viable solution here.
EDIT: I left an important question unanswered: With the LED itās important that it works continuously over hours because after an important message there will be only a few times when I happen to look at the phone. That is exactly the reason why sounds or turning on the display with apps is impractical. The purpose of the LED is to be on almost continuously or at least blink like every 10 seconds so after looking at the phone from across the room for over 10 seconds you can rest assured you didnāt miss anything. Coupling it with sound wouldnāt work in a cinema or a loud bar.
It seems you are mixing a few things up. āmAā means milli Amperes, which is the current. Watt is power (which is current x voltage).
A typical LED needs roughly 1.5 Volts (depending on the color) and current high-efficiency LEDs need at most 1 mA for eye-shattering brightness. Which totals to 1.5 milli Watt.
Whether or not you can transmit that power via NFC, I can not say.
But apart from this, I share the regret of all useful features being removed (LED, 3.5mm jack, accessible slots, ā¦).
They arrived! These little very cheap ledās arrived and blink in different colors when I hold them to the back of the phone with activated NFC. The problem seems to be, they always blink. I assume the NFC module thinks there is something to communicate and transfers power and after some time, when no communication happens from the other side, it turns itself off until it detects movement of those chips again. That could probably drain the phone and is not well controllable.
I will try now to write an android app that sees notifications and turns the NFC on and off to emulate the LED notification behavior. If that is successful next thing is to think how I can integrate them into my case protector in a way thatās not ugly and practical.
Lol, thatās awesome. Unfortunately, turning NFC on/off from an app requires root. If your phone is rooted, then for quick prototyping I recommend Automate. This should be fairly easy to implement. A few tips:
To not break NFC payments, you should allow NFC when the screen is turned on (and disable it when itās turned off). I would also check whether the antenna is somehow interfering with payments.
It would be cool to separate the LED from the antenna and move it to the front of the phone. Not sure how hard it would be though.
Having to root to be able to do that is annoying. That could have been handled by a simple permission. So Google does not trust me to handle such a permission while all my banks do not trust me to handle a rooted phone. I see I need to become an expert in āHow to root and hide it from your appsā too because companies think I canāt be trusted. Ok, end of rant.
Ok, I go down that route of rooting but I was hoping I could develop a solution for everybody who misses an LED. Maybe after prototyping I find a workaround.
I donāt mind breaking NFC payments because I donāt use NFC for anything. I use cards. I think I will try to configure it to turn itself on every 5 or 10 seconds briefly after a notification appeared to blink once until I removed the notification. Letās see if that works with Automate or if I need to code something, I did that before.
It would be cool to separate the LED a bit. I can try to unwind one of the circuits but my gut feeling tells me thatās a bad idea and wonāt work. I may try it anyway once I got them blinking how I want it.
Yeah, I feel your pain. I was actually surprised by this, because you can programmatically toggle many other features, e.g., Bluetooth, DND, Airplane mode, Power save mode, etc. But not NFC. Another option seems to be to provide elevated permission through ADB, that should work without root. (And a slightly tech-savvy user should be able to do it.)
And Iām curious, does the LED blink when the screen is off? I just tried it with an NFC tag and it scans only when the phone is unlocked and the screen is on. Payments work even when the phone is locked but the screen has to be on. So I would assume that the OS actually turns NFC off when the screen is off. But thatās just my assumption.
I always wanted to support phones made to last 5+ years so why not.
Ok, getting more convinced this will work somehow. 
Unfortunately, turning NFC on/off from an app requires root. If your phone is rooted, then for quick prototyping I recommend