lunch audio  - Page 1
Forum section: electronics / projects

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: February 19, 2014, 11:50:42 pm
content: so recently i talked to my principal about putting headphone jacks into the tables so we can listen to the TV's.what i want to know is how do i make sure the tables get the same audio. (buying a mp3 Bluetooth reviver board)(i have to be able to plug something in to the tv it self going on it doesn't have blue tooth)i want to find a way to go wireless instead of the wires to each table out of convenience and is a mustand be able to adjust each jacks volume individually .(max price for now we haven't talked it out that much 200$)

author: Skimask
author_rank: Super Contributor
timestamp: February 20, 2014, 12:11:16 am
content: A) The principal won't be able to do jack for you. Not even remotely their job.B) Ya, good idea, put jacks in the tables. They won't get wrecked immediately if not sooner and require weekly, if not daily fixing.C) $200? Not so much. well, maybe if you're in a one room school house.D) Multi-link bluetooth transmitters...not cheap.E) You won't believe me and will just go on by yourself and think you can do it...so why bother...

author: darko31
author_rank: Regular Contributor
timestamp: February 20, 2014, 12:37:12 am
content: Quote from: Skimask on February 20, 2014, 12:11:16 amPun intended?@fakelastnamelike_bobIf you really want to go through with this, it would be much easier to stick to analog technology. You could attach simple low power FM transmitter, and use receivers at the tables (cheap radios if you wanna make it really simple). People who have FM radios on their phones wouldn't even need receivers. There still remains the problem with powering the radios, if you use batteries, that would awful lot of battery changing, and if you use fixed supply, might as well make it wired.

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: February 20, 2014, 12:42:56 am
content: no no no i understand that all Bluetooth receivers will be placed under the table in water proof cases. agree with you on that.... -.-the jacks themselves will be replaceable because i will be using system like this =<<--> a jack on the PCB itself then another connector m to f so i will be able to replace them easily and it will have a casing around the jacks them selves.i believe you but no matter what there is a way to future proof200$ is shit to my school

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: February 20, 2014, 12:45:59 am
content: the radio is a great idea and i will also use it most likely with the.i never found the pun with out help

author: jeroen79
author_rank: Frequent Contributor
timestamp: February 20, 2014, 02:29:24 am
content: What is the purpose for this?Do you want to fit the tables in the lunchroom with audio so student's can listen to TV entertainment without disturbing others?What kind of students are we talking about? Teenagers?You could fit each table (or group of tables) with one wireless receiver and an amplifier connected to several jacks. But that will still require power.You could use batteries but who will replace them? Are you willing to do this?Why not restrict your installation to an FM transmitter and tell the students to bring their own portable radios.That will make supporting this much easier.

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: February 20, 2014, 02:54:49 am
content: What is the purpose for this?Do you want to fit the tables in the lunchroom with audio so student's can listen to TV entertainment without disturbing others?well yes i guess more the other way around we have the TV's on mute for now with subtitles.What kind of students are we talking about? Teenagers?yes 11-14 i hate them all. i know damages and stuff but i have it full proof so far with casein.You could fit each table (or group of tables) with one wireless receiver and an amplifier connected to several jacks. But that will still require power.You could use batteries but who will replace them? Are you willing to do this?well i know but i would rather have a receiver with jacks for convince of me but yes i am switching to radio i am using battier but still do not know witch kid would be good for 3-3 1/2 hours and it would connect to the end of the table to charge.so no replacing. yes i am doing it my selfWhy not restrict your installation to an FM transmitter and tell the students to bring their own portable radios.That will make supporting this much easier.i know but the jacks is the main way i am getting money here if i were to do that i may only make 10$

author: TheBorg
author_rank: Frequent Contributor
timestamp: February 20, 2014, 04:07:48 am
content: So you're planning to put all this equipment in, and get a profit, for under $200?For an entire room? Not going to happen... just saying that now. By the time you get the transmitters and receivers in, you will be close to that budget. Add the cost of rechargeable batteries to this and you're way over budget. Then you run into problems- who charges the batteries? Where will they be kept? Who plugs them in? Who switches them? When?Not trying to be a downer, but I think this idea need more thinking through before you set a budget for it. Don't forget that you are factoring the time in working here. You also seem to be intent on keeping the system running, and charging the batteries all yourself. Are you getting paid for all that?Just don't get ahead of yourself here, take a minute and slow down and consider all the options for this.Why not just have a row of TVs with the volume turned low, and only those TVs can have the sound going? Create a loud/quiet side of the lunchroom. And why do you have TV's in the lunchrooms anyways?

author: SeanB
author_rank: Super Contributor
timestamp: February 20, 2014, 04:34:57 am
content: As pretty every cell phone has a FM receiver built in ( though for the US market they often are turned off in the firmware for some strange reason) a cheap ( $5) car FM transmitter will do for covering a 10m range, just connect the FM output to a short wire antenna and you are done.

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: February 20, 2014, 06:18:18 am
content: don't worry about batteries i am going to make it so it automatically shuts down the receiver in 30 min. also lunch ladies fold them up at the end of the day so the chargers will be built in and when they fold them up they will also plug them in. 200$ maybe not exactly idk yet. i am only replacing adouio cable when idots shove food in them.st don't get ahead of yourself here, take a minute and slow down and consider all the options for this.Why not just have a row of TVs with the volume turned low, and only those TVs can have the sound going? Create a loud/quiet side of the lunchroom. And why do you have TV's in the lunchrooms anyways?tv's mounted in walls already. also quiet lound thing there is no such in 6 - 8th grade

author: jeroen79
author_rank: Frequent Contributor
timestamp: February 20, 2014, 12:54:30 pm
content: If you put [ quote] [ /quote] tags around the text you are responding to it will be easier to read.Quote from: noah_fakelastnamelike_bob on February 20, 2014, 02:54:49 amSo you want to charge people for the use of your audiojacks?How will you enforce that? Will you patrol the room to catch people using them without paying?

author: codeboy2k
author_rank: Super Contributor
timestamp: February 20, 2014, 01:22:29 pm
content: Are you a teacher? Or perhaps an enthusiastic student? What's your role at the school? You really need to write out a detailed plan for implementation and maintenance, who (or what department) is going to own what, and not just say stuff like "the lunch ladies will do it when they fold the chairs" .. did anyone ask them?I agree with what's been said already.. you should only provide a low power FM transmitter and require anyone who wants to listen to the audio to use their own receiver. The ongoing maintenance cost is 100 times lower with this approach.A second approach might be to use a WiFi streaming audio, and your school probably already has wifi in the lunchroom anyways. Users can listen with the phones or laptops. The downside is that WiFi audio might lag, and there might be a noticeable latency.

author: noah_fakelastnamelike_bob
author_rank: Regular Contributor
timestamp: February 21, 2014, 12:28:51 am
content: scratch every thing i am just going to buy a fm transmitter and make it look more professional (audio audphoolelry) and sell him both for like 50$

author: electronics man
author_rank: Frequent Contributor
timestamp: February 21, 2014, 12:58:29 pm
content: Quote from: noah_fakelastnamelike_bob on February 21, 2014, 12:28:51 amHow are you going to do that?

author: mdszy
author_rank: Unknown
timestamp: February 21, 2014, 06:49:55 pm
content: From his profile, he's 13 years old.Look, kid. You're trying to get in way over your head and you have no idea what you're doing. You don't have any idea about how much things cost and you're not taking into account that hey, nobody cares. Nobody's going to use this thing. Nobody is going to PAY to plug headphones in. It's plain dumb to think that anyone will.Go back to making stuff for yourself. Don't be diving headfirst into stuff when you don't have any clue as to how things work or how to accomplish things.

author: Legit-Design
author_rank: Frequent Contributor
timestamp: February 21, 2014, 07:01:04 pm
content: Quote from: mdszy on February 21, 2014, 06:49:55 pmNothing wrong with trying, failing is the best way to learn. I say go for it. Get one of those cheap FM transmitters, the ones for car or whatever, powers it from whatever. Low power fm transmitters can be operated without any problems. These days everyone has headphones and cell phone, that cell phone has fm radio. Usually mp3 players include fm radio, cheap fm radio receivers from china can be given away practically for free.

author: SeanB
author_rank: Super Contributor
timestamp: February 21, 2014, 07:07:40 pm
content: I bought a FM radio for less than the 9V battery that powers it. Same with the FM transmitter, I bought the RDS version for $10, the regular one is $5.