I'm new to Arduino and need some help building a science project with my son. See the attached PDF for a description of the project and a circuit diagram. I've tried to figure this out, but this is all new to both of us. We would like the annunciator to have a recorded message (like "Baby on Board").
Thanks in advance for any assistance.
Invention Convention.pdf (160 KB)
Please include the description in your Post so we don't have to download stuff.
For posting images see this Simple Image Guide.
Separately, this sounds like a project whose purpose is to allow parents to ignore their most important responsibility.
...R
The circuit itself is simple. The logic is NOT. When should the alarm go off? When is a child "left unattended"? Keep in mind that false alarms are as bad as alarms not going off when they should. A few false alarms and the system will be disabled/ignored, just like how fire alarms in this city are routinely ignored (I've also learned that a fire alarm is almost certainly a false alarm and is best ignored, after a few dozen fire alarms - not counting scheduled & announced testing - and not having seen a single fire).
Maybe the driver left the car to buy something, but the other parent is on the passenger seat. OK, another pressure switch. But what if that pressure is not a passenger, but a big bag of shopping?
Maybe the driver is just refuelling, and right next to the car. That takes way more than two minutes. Engine is definitely off in this situation. On the other hand two minutes is more than enough time for the driver to walk away from the car and enter a building, out of hearing of the alarm. Passers-by would have to take action in that case.
What if the driver just used the child seat for his shopping? Easily the weight of a small child. Shopping left behind in the car is usually not a serious issue, definitely not worth sounding the alarm over.
Probably the difficulty of this problem is why there are no such systems readily available on the market, let alone come built in into a child's seat, while children left behind in a car is a real issue.
Everything from here...
wvmarle:
When should the alarm go off?
... to here ...
wvmarle:
children left behind in a car is a real issue.
... is doubtless valid.
But surely the idea is for the son, with a bit* of help from Dad, to get his hands dirty on some coding and wiring, and to get his mind round the thought processes that go into designing and constructing a school level project? I doubt if Buerger & Son are expecting the likes of Bosch or Hella or Lucas**to be fighting each off with clubs to hand over suitcases full of cash to get this project to market.
I think we should try to advise them on how to go about realising this project at least to the degree where a model thereof (maybe even just with limit switches, not weight sensors, in small model seats) can be presented at the fair or open day or whatever.
** remember them?
Buerger:
this is all new to both of us.Thanks in advance for any assistance.
There's really no substitute for starting with the tutotials here, which are also in the IDE at File > Examples.
In particular I think you will need to digest the idea behind blink without delay, because you will need at some stage to have the timer running while the system is still responsive to the switches.
Thanks to all who have responded, and provided input.
As some have commented, this is just a prototype which will clearly need fine tuning.
We're just trying to get a "proof of concept" design working. What parts (or kits) would get us started?
Buerger:
We're just trying to get a "proof of concept" design working. What parts (or kits) would get us started?
You could realise this with just an Uno and a handful of jumper wires and a couple of switches like the one s below. Use the built-in led as your annunciator for now.
These switches can usually be wired no or nc; just make sure the ones you get can be (3 connectors).
this is an intermediate project, not a beginner.
doing something after you lose power, seems to violate the laws of thermodynamics. we don't do that at the beginners stages.
so, if you put in your baby in the seat, the switch changes.
When you take the baby out, the switch state changes back.
so, we know when the baby is in the seat.
What is the other switch connected to ?
assume you put the baby in.
then close the door
then open your door
get in the car
close the door.
assume you do the same, but this time, open your door, realize you left your cell phone in the house,
close the door, go get your cell phone.
same switch states, different conditions.
you need to get the correct numbers of sensors and get the correct states before you start playing music.
============
all this is simple and you can buy this sort of stuff. if you follow the designs of what is currently sold you can move along quickly.
what I found to be the most common is a hand shaking of phone and baby device.
as long as the babyseat is near the phone, they talk. once the distance causes loss of signal the alarms go off.
the phone alarms and the baby alarm sounds. That way, it is easier to find where the baby is if you are in a store.
Even if you keep the construction simple, this are questions you should think about. Good chance that a random passer-by would start asking such questions - like I would do. Real world scenarios that are likely to happen but go against the exact sequence the designer has in mind.
Incorporating everything in your design may be impossible, it's important to think about at least a good number of alternative scenarios. Especially situations like a routine refuelling stop.
Now do start building.
Pressure switches or FSRs are suitable seat sensors.
The DF Player Mini is an easy and inexpensive solution for playing the pre-recorded message.
Add some flashing lights for good order.
sayHovis:
You could realise this with just an Uno and a handful of jumper wires and a couple of switches like the one s below. Use the built-in led as your annunciator for now.These switches can usually be wired no or nc; just make sure the ones you get can be (3 connectors).
Thanks. Is there a pressure pad that can be wired NO or NC? We are trying to come up with something that can be placed in the bottom of the car seat, and also in the driver's seat. The switch you cited has the correct logic, but is not ideally suited for our application.
Buerger:
The switch you cited has the correct logic, but is not ideally suited for our application.
In fact, thinking a bit more about it, you can in any case handle the logic of the switch in code. You won't actually have the switches in series like in your diagram; they will both be read independently in your code, into two different Arduino pins.
(edit: Neither switch will "energize" anything: The Arduino will be monitoring them both all the time. It can easily be programmed to detect changes in occupancy, and make decisions based on those changes and the sequence in which they change.)
So even if they both read "high" under normal circumstances, you can decide in the code what it is you're looking for. What you're looking for is the child's or driver's seat to be occupied or not. If the child's seat becomes occupied, or is occupied at start up, and the driver's seat isn't, start the timer, kind of thing.
You could probably get started with 2x no pushbuttons. In real life you would "digitise" an analog sensors like the FSR suggested, by its value being above or below some threshold, and know the state (un/occupied) of each seat.
My advice: put the specifics of the project on the back burner while you work through the tutorials. The known vendors have starter kits which will make that easy for you. But keep the project in mind as you do, then as you encounter various concepts, you will have a series of Aha! moments when you realise this or that concept is probably going to help.
sayHovis:
But surely the idea is for the son, with a bit* of help from Dad, to get his hands dirty on some coding and wiring, and to get his mind round the thought processes that go into designing and constructing a school level project?
I think the teaching / learning should encompass at a very early age the concept of appropriateness - in other words, even if the complexities already mentioned could be overcome, would it be a good idea. Personally I don't think it would be, because it conveys the impression that the relationship between parent and child can be delegated to a machine.
There are probably dozens of other projects that could exercise the same Arduino skills.
...R
I'm out.
OP you're welcome to PM me.
What ever you design, make sure it does not void the warranty on either the child car seat of the car's seat sensors.
Paul
Robin2:
There are probably dozens of other projects that could exercise the same Arduino skills....R
Since this is a school project, and I would assume a High School, we cannot be sure that the assignment was given to every member of the class or on a list that was created by some teacher.
Planing and making a project does not require critical thinking about the need for a project.
The concept of creating an alarm when conditions are out of range is most certainly within the realm of the Arduino.
[political rant mode ON]
I hate to go political, but you are correct, it is not to be left to some machine, according to politicians, it is to be determined by the State.
[political rant mode OFF
That's funny!
I was sure I contributed to an earlier version of this thread, but can't find it among these: 1 2 3
For under $250.00 you can purchase one: Car Seat Alarms That Alert Parents There's a Baby in Back Seat Do a bit of research to see what you are really in for. What if it fails who is liable?
Good Luck & Have Fun!
Gil
Hi,
Your subject title is "Device that will alarm if a child is left unattended in a car seat".
I would assume unattended by a responsible adult, so seat pressure is not going to detect a "responsible adult", I see in this case;
The underlined suggestion may be an easier and less obtrusive way to detect an adult, as you may have the adult in any seat in the car.
Also it makes sure the adult is responsive and hasn't gone to sleep with the child.
Just a suggestion.
Tom... 
back to the actual requests, father/son learning, playing, encouraging experiments and trial and error.
I don' think anyone expects this to every be marketed.
TWO ESP8266's
or two radios with arduinos -NANO is much better for field use, UNO is better for bench
a switch to sense when the child is in the seat
a temperature sensor to alert of the area is too hot or too cold.
all this is stuff you can put together from what is currently availalbe. and each step is on the beginner side. the project as a whole is advanced beginner
