Design and Install a whole-school LED Bell System

Projects General Guidance
1

A few months from now, I'll be running a summer project with 9th and 10th grade high school students to create a large scale LED installation project at our school- I've started learning about the Arduino platform and using it to drive LEDs, and I'm posting here seeking guidance, thoughts, and advice about the challenges this project will need to watch out for that I won't foresee because of my inexperience.

I'm very early in the learning process and I hope that over the next two months I can develop a basic grasp of what I'll need to know. I'm hoping that people here can help me to locate the right resources to be learning from.

  1. Our Project

Our high school doesn't have a bell system, and we want the students to have this opportunity to design and create it for themselves and learn a lot along the way. Over summer, a group of students will be learning about designing LED circuits, LED strips, programming patterns, and installing them around the school

  1. What it will look like

The students will have a lot of ownership, but at the end of the project we want to have LED strips running around the top of classrooms and down corridors. These LED strips will fade into different colors based on the time of day: at 8am, when school starts, the LED's might fade up with yellow like the sunrise. At 8:40, when the students go to their second class, the LED's would transition to Orange. This change will be easily visible in all ten of our classrooms and on both sides of our two corridors.

  1. The challenges I can see

I don't know how to design this project, and I'm starting with the basics- but some things that I don't even know where to begin how to learn about:

  • What are the basic principles for designing the circuit and power requirements to keep the system robust? i.e, we'll need to make sure that one problem doesn't crash the whole system

  • How can we create the system so that it changes on a time schedule? How can we design it to make it easy to change the schedule?

  • How many LED strips can be connected together? Is this project best concieved as a continous system of 100+ meters, or do we create many smaller units? Each with their own microcontroller?

  • Assuming that many microcontrollers are required, how do we network them together to allow central control? How do we design to minimize costs?

  1. My next steps

I'm trying to find experienced people who can consult with me to help support my students to make this project a reality. As you can see, I am only just beginning- and so the main challenge I face is that I lack the technical understanding to even begin to learn how to build something like this. I'm starting with the basics- learning how to program one strip, how it interacts with the arduino, following along with instructibles.

  1. The questions:

  • What resources would help me to learn how to approach this project?

  • What are the problems with the idea? What are the challenges we'll need to solve that I can't see?

With good faith and tenderness,
This is a high school teacher (in over his head)

2

I would guess that in a school environment fire/electrical safety is a top concern.

As you have no experience, how are you going to prove that the system you are intending to build will not catch fire and burn the school down?

Worst case scenario is that the school's insurance company decides that it doesn't like the idea of a custom built unapproved lighting system and the whole project gets canned.

This video will give you an idea of the technical challenges.

3

banj:
A few months from now, I'll be running a summer project with 9th and 10th grade high school students to create a large scale LED installation project at our school-

I'm wondering if I should start learning music with a view to running a piano summer school ? ?

I'm all in favour of learning and opening up things to students but this sounds like a mammoth undertaking for a newbie with a deadline. Some of the students may be better at this than you are.

And it won't be cheap. What is your budget?

You may find some useful ideas in Planning and Implementing a Program

...R

4

mikb55:
I would guess that in a school environment fire/electrical safety is a top concern.

That's true, and a great point. These are exactly the risks that have to be researched, because proving that it won't catch on fire is critical, and something I don't yet know how to do. In the past few hours I've learned a touch about calculating power consumption, what kinds of safety precautions can we take with a big build to establish strong safety margins?

Robin2:
I'm wondering if I should start learning music with a view to running a piano summer school ? ?

Shoot for the stars!

Robin2:
I'm all in favour of learning and opening up things to students but this sounds like a mammoth undertaking for a newbie with a deadline. Some of the students may be better at this than you are.

My students will all come to this project with really different levels of background knowledge- they'll be learning from each other on this one. One of the reasons this project felt feasible to me is that [I imagine] the basic premise of the undertaking is simple. An LED strip changing color to a schedule seems comparable or simpler than the kinds of projects I see all over the place- Sound reactive room lighting, for example.

Once you can do it with one strip the big challenge is figuring out how to make twenty units respond to a central schedule and ensure safety. Is that true?

Robin2:
And it won't be cheap. What is your budget?

You may find some useful ideas in Planning and Implementing a Program

...R

The school was about to spend 6k on an audio bell system and we decided to try this instead, so doing it for 3k would be a steal. To try and decide the reasonableness of that, I looked at the Philips Hue system for home automation- their strip lights and application would seem to allow the kind of scheduling that I'm talking about, as well as being networked. I want my students to put together a solution, but at the end of the day, if we bought 25 philips strip lights and a bridge and deployed them throughout classrooms, would that not amount to the project I've described?

Thanks for the video recs, mining them for insight now

5

So let's see what Ideas I got :smiley:

Because High school are large/ big you will need a lot of led stripes, well not wasting that led stripes I thought of another way, because you gonna put the led stripes in sections, like above classrooms and corridors you can divide the led stripes in sections, what I mean? Each class room got power plugs on the walls for each led stripe you will need regulator.

So instead using a big regulator high voltage for 50~100meters of led stripe you can divide the stripes in sections and put small regulators better and safe.

Now about the time, you will need a clock/timer you know that small modules with the coin cell battery that
tells you the time, you can use one of those, now what about lighting up all the leds, well for that I think it's a nice way to use nRF24L01 modules, making a wireless communications between them, the small nRF24L01 are small wireless modules 2.4Ghz, you can put in each led stripe one of them and use them as a communication between all of them to light them up..etc

I can tell more and more but better read this 1st :smiley: writting a lot makes it harder to head.

D.60

6

I'd agree - make it modular, and don't think of it as ONE BIG PROJECT.
Too many LEDs will drive everyone crazy - so at the very least, you can reassign/reprogram...

If it is too complex as a single project, it will overwhelm everyone - especially you, trying to coordinate it.

This would also work with the concept of distributing the implementation risk and local power loading, and with localised LED controllers, you can vary the mood & colour/theme in individual areas. And they will fail independently, without taking the whole system down.

In fact, I'd probably put a $5 Arduino Nano, a muti-drop RS485 interface, a LED driver and suitable power supply for each room / corridor - say $25 + LEDs for each location.. Each Nano programmed with an EEPROM map of the lighting effects (which can be changed-uploaded if ever needed).

Student groups can be assigned to different development roles - which can be worked and tested independently -

  • LED control, Hardware & software (Nano or Uno, with WS2812 strips are bright, easy & cheap)
  • Communications, Hardware at nodes any small Arduino,
  • System host controller, Hardware & software (make two for redundancy) a MEGA will give you more memory to use in the future.
  • Hardware integration design factors environment, maintainability etc
  • Software integration design factors, fail-safe, synchronisation etc

If you use time-of-day as the master event (add $20 to read the time from somewhere NTP, cellular, RTC etc).

You could use a bar-graph effect in the strips to indicate remaining time per class period, or in the corridors, to offset against seasonal daylight brightness, and/or time remaining 'to be in next class' etc

The software planning is just as important as buying an Arduino and turning it on.
In the above scenario, you have two sets of software in multiple nodes that need to play nicely with each other, but will give really impressive results. And I'd add a bell interface somewhere in the mix for later - when they want to ring a real bell!

Remember to document the code, wiring and operation as you go!

7

I agree completely with the advice "don't think of it as ONE BIG PROJECT."

And the idea of a series of stand-alone modules that can communicate with each other (or at least can be communicated with) sounds sensible. That way you can develop and test the master controller and a single module and then just replicate the modules.

There are off-the-shelf systems for communicating over the electricity power cables - I think you just plug something into a socket wherever you want communication. That may be worth considering for a large building.

Before committing to nRF24s (which are cheap and effective) I would buy a few and test how well they work in the building. You may find that walls and stuff prevent transmission and you may need a daisy-chain system A to B, B to C etc. rather than A to B,C,D etc

The possibility of each module acting stand-alone with its own Real Time Clock should also be considered.

What about jumping into the present century by sending a WiFi message that is picked up by the students' phones? Probably get the cost to the school down to $0.3k

The previous paragraph brought to mind the idea of mounting a tablet on the wall of the class room and sending a Wifi message to that. You could write a program for the tablet to display all sorts of fancy colours - and make sounds.

...R

8

Before committing to nRF24s (which are cheap and effective) I would buy a few and test how well they work in the building. You may find that walls and stuff prevent transmission and you may need a daisy-chain system A to B, B to C etc. rather than A to B,C,D etc

About that he can create a network of nRF's making the nRF's communicating with each other in a chain, you sent the signal just to one of them and the others start communicating with each other. I don't think wireless communication will be a problem.

From my personal experience with the small nRF's they can pass thru 2 walls at least in a distance of 10 meters, if you got them in open view with each other they can communicate at the distance of 140meters

9

Much as I criticise WiFi for reliability in mission-critical applications (including business systems), this sounds like the way to go here.

And for WiFi, think ESP8266.

10

anyone notice he said 10 rooms, 5 on each side of the corridor ?

this is not a large project by any means. rather, is is more simple than complex.

one Arduino to fire one relay and each of the 10 rooms can have a local power supply turn on the LED's
if you think of non-blinking Christmas lights, you can have 10's of thousands on one tree with one switch.

step 1) blink 1 LED
step 2) combine LED's in series to make groups that will work from a higher voltage power supply.

add in a real time clock (RTC) so that at 9:00:00 the lights change.

options for the LED's are multiple LED's with single colors
multiple color LED's
serial controlled LED's

without knowing the budget, we cannot know the direction.

If this is to be done on a very low budget, I would offer that adding LED's behind a clock or on a bar could be done in a few days. you need one for each room.

Although in the end, it could be a huge pile of soldering, I do not see that you need more than a simple microcontroller.

The best thing we can offer our new friend is to make a SIMPLE project that the kids can do in stages.

=========================

Let's change the scope

one LED bar to go over one door.
time keeping so that at different times, the LED's change colors.

I think that is a simple task.

next question is how many kids,
will they all learn to program, so each would need an Arduino ( or ESP )
one power supply each kid or pair of kids
one soldering iron per kid
resistors.

if this is REALLY low-low-low end stuff, I would go with cardboard or wood, punch holes, glue in the LED's and wire together in series.

I know you would think I am INSANE, but I would not rule out running at raw AC without a formal power supply.
OK, you can substitute 'know' for the word 'think' in that last sentence.

11

if this is REALLY low-low-low end stuff, I would go with cardboard or wood, punch holes, glue in the LED's and wire together in series.

Well not sure what kind of high school is it but spending all the summer just to punch holes and glue leds on cardboard :smiley: that's like a 5$ project.

12

Splitting the students into roles is a good idea but then only one student gets to do the fun stuff of flashing the LEDs. The others are working on the "operating system" where they only get black boxes to stay black.

The user interface for the Principal is going to be one of the hardest parts. There are always exceptions to the standard school day. Holidays, short days or whatever, must be able to be programmed into the system at least a week in advance, probably a whole semester ahead. How do you present that information on a screen for the Principal to set up the school semester?

I would structure it so that each student gets a chance to play with the blinky lights. Maybe each classroom/hall hardware is built by the students directly. If you have a reasonably simple core operating system then the students can each program their own system to communicate with the central server. Everyone can make a slightly different colour animation, to their own preference. That can even be a competition to make the best animation. That is an absolute nightmare for maintenance if you have different software in every classroom 5 years from now.

Maybe you can strip down the hardware small enough that the students can take home a 1-foot strip of the LEDs and an Arduino. If they can experiment at home, you will get a much better engagement. Then they can upload their code onto the actual classroom units later. That also makes this an ongoing class, where each year your students try to outdo the previous year and they upgrade the animation in their own classroom. And every student leaving your program has an Arduino of their own now.

If you are lucky, you will find one geek in your class who likes writing operating system software. Otherwise you need to buy it off the shelf, write it yourself or advertise on this forum's "gigs and collaborations."

13

Domino60:
Well not sure what kind of high school is it but spending all the summer just to punch holes and glue leds on cardboard :smiley: that's like a 5$ project.

well, if it takes all summer to punch holes in card board.... guess we are way to high tech for that level......

14

well, if it takes all summer to punch holes in card board.... guess we are way to high tech for that level......

well it can be a chines summer high school project, mass production punching holes in card board :smiley:
selling them on ebay, Ebay : " Card board Punchman Led" (safe for kids). :smiley:

ahah

:smiley:

15

MorganS:
Splitting the students into roles is a good idea but then only one student gets to do the fun stuff of flashing the LEDs. The others are working on the "operating system" where they only get black boxes to stay black.

The user interface for the Principal is going to be one of the hardest parts. T

For a first year curriculum, I would go with the repetitious task of each pair of students doing one arduino, and one 'bar' of LED's
a master time clock does not have to be an Arduino, the PC or even a cell phone could be the time clock and have every day, half day, holiday, summer school, days off....
if each classroom had one Arduino, one power supply and one bar of LED's
it would be a very achievable task for the students and too too complicated for the instructor. certainly something that could be done by a veriest tyro both on the instructor and students alike.
all of them getting a signal, wire or wireless would not be a problem.
not sure I like the idea of a count down timer, students focus on how long before the bell rings, not how much more can I learn in that time.
certainly a one semester class to get this working.
but it would mean getting power to each class.
semester 2 ?
multi color,
local setting ( individual teachers giving tests with time limits ? )
semester 3 ?
chase lights, follow to the exit ?

I think the real issue is the budget.
certainly, getting addressable, multi-color LED's and 100 meters of channel to hold them
and an UNO for each kid would be huge dollars.
on the other end is one NANO, an RTC, resistors and relays.
so, say $40-50 per meter x 100 meters, on the high end
$100 on the low end with only a dozen lights in a 1 meter strip in each classroom.

16

Domino60:
well it can be a chines summer high school project, mass production punching holes in card board :smiley:
selling them on ebay, Ebay : " Card board Punchman Led" (safe for kids). :smiley:

ahah

:smiley:

you means Card board Punchman Led for when you are children with school project

I looked at a stair lighting project. one LED per step, with wood to appear to be part of the stairs, holes for LED's cut out for wires.... cosmetics was more important than anything.
if you purchase the aluminum channel along with LED ribbon, it costs about $10 per foot, plus wire, plus fasteners, plus power supply, drivers, repeaters, power wiring to power the each class with approved wiring circuits....

17

not sure I like the idea of a count down timer, students focus on how long before the bell rings, not how much more can I learn in that time.

The count-down could be at the back of the class where the teacher can see it. Or the students might choose a 5-minute warning flash.

and too too complicated for the instructor

and NOT too complicated?

18

We keep typing here but I don't see the OP.
I think we should wait to hear his opinion.

19

Quote

and too too complicated for the instructor

and NOT too complicated?

yesterday I deleted a post for multiple errors. voice to text on my tablet. not sure where it got Lobster Bisque from or some of the other phrases....

but, yes, not too complicated.

20

The different ideas being offered here are so exciting, it feels like this level of project (in some form) makes sense as an achievable challenge for the students to be working on. I was hoping that it would be possible for them to create it during the summer and install it for the new school year- but it definitely sounds like it could easily be a one or two semester class, depending on how complex we decided to shoot for.

I need to research the different components mentioned. I completely agree that a modular design makes sense, and it's important that I keep the cost per unit low enough to deploy a large number of them. That way, rather than feeling like a random out-of-place thing, each unit contributes to the overall effect. Several down the corridor, one or two in each classroom, bending the LED strips to make geometric shapes (or layering them to allow for patterns).

I agree with the idea that the control system will be one of the most complicated aspects- it's true that I need to help the kids to arrive at a design which can be changed and updated centrally with ease. The system that they build can support all kinds of irregular school days and schedules if we design with the foresight to make it simple to keep updated.

It sounds like a unit will basically be composed of the arduino nano, the LED strip, the power supply, and the network interface. I can see the benefit of having each unit be self-contained with a RTC to eliminate a central point of failure- but would the reduced complexity outweigh the benefit of having a central updating mechanism?

Would it be possible to build a bare-bones, password protected web interface to fill in the time of change and the color to change to?

I think I have an understanding of how the units will function, except for the networking and control features (the most complicated, really). Whatever components we come up with, we'll get some and test them out with the kids, check the conditions- but which approaches will offer a good balance of robust design and ease of operation?

And thank you, deeply, to everyone- it's really something to be able to come to this forum and engage with people about these ideas