That would be funny you're at a club with this phone and doing phone calls
RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
31–40 of 54 posts
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#32Earlier quoted context omitted.
So I was referring specifically to this phone hardware project and to flashlights, which don't fly... But my thoughts on drones are also that it's very different if you're building consumer class things that are meant to be re-used or what's going on in ukraine right now. They're using high amp rate cylidrical 18650 and 21700 cells in 6S2P and 6S3P packs for one way trip munition drones where you don't particularly c…
If you’re getting into bigger (kg+) drones, it starts to make sense to shoot for 100cycle+ (and for 10kg+, 1000 cycle-ish) lifespans. The economics and the physics work out. But for very tiny systems like the single cell drone featured, the equation starts to favor squeezing every last drop of energy reasonably possible, which means that you can easily get caught out downwind or “stayed to get a few too many pictures…
> ...like the single cell drone featured...
Featured where?
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#33Accepting 5V over the RJ-11 jack seems asking for trouble. Someone is going to plug it into a regular phone socket at some point, so it needs to be capable of surviving at least 60VAC. Even if a secondary pair is used, there are so many different wiring standards in use, it'll end up plugged into something live sooner or later.
Luckily telephone lines are very current limited. You'd be hard pressed to draw more than 100mA even with a dead short at ring voltages. One zener diode might be all you need.
Also not the most unusual thing I've seen over a RJ11, which includes keyboards, RS-232, other random digital IO and full USB with data. But these are normally on items that are not phones.
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#34That would be funny you're at a club with this phone and doing phone calls
or in the corporate office
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#35Accepting 5V over the RJ-11 jack seems asking for trouble. Someone is going to plug it into a regular phone socket at some point, so it needs to be capable of surviving at least 60VAC. Even if a secondary pair is used, there are so many different wiring standards in use, it'll end up plugged into something live sooner or later.
Luckily telephone lines are very current limited. You'd be hard pressed to draw more than 100mA even with a dead short at ring voltages. One zener diode might be all you need. Also not the most unusual thing I've seen over a RJ11, which includes keyboards, RS-232, other random digital IO and full USB with data. But these are normally on items that are not phones.
also 1-Wire
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#36Accepting 5V over the RJ-11 jack seems asking for trouble. Someone is going to plug it into a regular phone socket at some point, so it needs to be capable of surviving at least 60VAC. Even if a secondary pair is used, there are so many different wiring standards in use, it'll end up plugged into something live sooner or later.
Dunno about you but I don't know anyone with live RJ-11 jacks in their house anymore.
I have one. It comes from my cable modem.
We still have a landline. It's part of the cable package, but it mostly just gets robocalls.
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#37Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#38Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#39Earlier quoted context omitted.
I've got them, powered by an Adit 600 in my basement.
What do you use that for?
Calling people and playing with phones. I have an internal Asterisk server for me and a few friends. The nicest thing is that when the phone rings, it's a person who I know, not a scam. (Unknown external numbers get direct to voicemail)
Also great for my friends' kids. They can call each other or their grandparents or whoever, without having to touch a cellphone that tries to distract them with YouTube or whatever.
My house uses mostly analog with the Adit 600 (6 lines, 3 using the 70s wiring in the wall, 3 dedicated to specific phones). Everyone else has cheap Polycom desk phones and uses SIP/RTP.
Re: RotaryCell: Making an unmodified rotary phone work over LTE with an ESP32-S3
#40We have a similarly converted rotary phone at my local astronomy club's observatory, used to receive visitors. It's driven by an arduino if I remember correctly. The main issue is that the sound quality of its built-in speaker is quite poor, especially compared to modern cell phone speakers we're used to nowadays, with a narrow frequency window and frequent echoes.
Interesting. I remember voice clarity being exceptional on old handsets and being really subpar on gsm and later. Only now we FaceTime voice and discord the quality seems to be coming back. How can that be if the speakers in phones ubiquitously were so bad?
My understanding is that at some point the audio of phone calls ended up being compressed multiple times on its way to the receiver as it went through different voip setups and such.
Prior to that, uncompressed or compressed once calls weren't so bad on bad speakers.