[Galaxy S 4 i9505 Original Android Development] yaqoobhisbani:
I have been following this ROM from long but never posted a word here. So, this is the time. Well, I got S4 just in march 2017, yeah it's 2nd handed because I couldn't afford. As of me, I'm just another newbie developer still learning languages but I've always been rooted with whatever Android I use, just to have fun tweaking around things. ;)

My experience with S4, It's Sprint variant (SPH-L720) unlocked & I'm in Pakistan, we've GSM network here. Within few hours after buying, unfortunately, touch glass got cracks due to accident on top left. :( Fortunately, It's still useful and working fine. I tried several ROMS but nothing worked unless I came to know Optimized Lineage OS.

The very first build I installed was Stable2 which I used for next 2 months. I faced several issues but dealt with them on my own. The first was definitely the GSM network issue. After been without for a week, a build.prop fix worked like magic. Adding 2 lines, [telephony.lteOnGsmDevice=1] & [ro.telephony.default_network=2] always works for me. As per my knowledge, the first one somehow enables GSM in ROM while the second just selects the GSM only network by default which is usually done through *#*#4636#*#*. BTW, after stable4 I don't need the second line.

After that, I was very happy to have the problem sorted out but it wasn't the end of GSM issue there. I received signals, sms & data was working brilliant but I wasn't able to receive calls. It just rings on the other side but nothing shows up at my side. After searching a lot, I came to a thread where a given patch fixed the issue. The patch just adds two RIL library files from tmobile. Links is below

https://xdaforums.com/galaxy-s4-sprint/general/fix-calls-receiving-gsm-t3213006

Later, a very weird issue which caused to turn display off or black whenever there is a call coming or going. I wasn't even able to answer or reject calls. Thanks to the developers, there were "power button ends call" & "answer call with volume buttons" toggles available in ROM which did a temporary fix. But still, I couldn't call on FB Messenger, WhatsApp and also I couldn't know who is calling.

I came to know the issue is related to proximity sensor and on testing, It was always giving "near" result means the phone is near to an object even when it wasn't. I wasn't sure either this is hardware or software problem as my S4 also went through an accident. So, I decided to tweak around software who knows what comes next ;).

Finally, an app named "Proximity Sensor Fixer" from playstore fixed the issue in an unusual way. The normal process of that app never worked but there was force calibration option which did fixed it for some seconds but It was broken again. So, what I did was to hit the force calibration and uninstall app as soon as possible so It can't proceed more. Now, this little trick gave me persistent fix. Even after switching roms to stock firmwares. Nothing messes with proximity sensor. :D

I still have GPS broken, it doesn't even work but I never use it. What I think is it's hardware issue definitely the GPS antenna isn't in contact.

Coming to the ROM, Optimized Lineage OS is great ROM for those who want stability, stock-level battery life, debloated, fast and pure Android Experience like Nexus or Pixel. And all the credit for this goes to [MENTION=5968293]side[/MENTION] and team who've been working hard to keep S4 alive from so long and also will in future. I'm a junior-developer too and understand the efforts it needs to keep the ROM rocking. I would've donated for this but unfortunately I can't because PayPal isn't available in Pakistan and I'm a student too. But it doesn't end there. I will be looking forward to give people a hand in this thread and [MENTION=5968293]side[/MENTION] you can count me in for testing. I would love to test and report bugs in your builds.

I would just say that I'm pretty happy for this ROM & will stick to it until my S4 is alive.

[MENTION=5968293]side[/MENTION] I would just like to see network speed meter in status bar just like it was in OptCm13. 3rd Party apps do the work but it is way much cleaner in actually integrated thing.

Tons of thanks to side and team for awesome development.

Regards,

Muhammad Yaqoob