Is this possible?

[TSMSTSA]

My kids have a project and Im not sure it's possible. Here is what they are wanting to do:
The kids have a challenge to create something to assist with school safety. After speaking to the principle and several other teachers, they want to create two things and Im not sure that it is even possible. First, they want an NFC door lock for the bathrooms, where after the kids scan their card, the door would unlock, and then their name and time would be stored on the reader to be retrieved at a later time. Second, they want to create an emergency button system where a teacher could scan their NFC card and the main office would be notified with an alarm. We are all learning together, and are willing to put in the time, but are not sure if this is even possible or where to begin. Any guidance would be appreciated!! Thank you in advance 😃

[dastels]

The bathroom door system seems doable enough. I'm not sure what the second entails. " a teacher could scan their NFC card and the main office would be notified with an alarm" ... what exactly does that mean?

Dave

[T_Mo]

These are great ideas, and undoubtedly can be accomplished (assuming the kid's project would be allowed to connect to the school's internet portal).

If this is just a demo project, it sounds fun.

A long-range concern is that if they build it, and it goes into use, who is going to do maintenance to keep it running? Door locks will wear out or break. Internet services come and go.

Since it's a school-based system with access to personal information, there are information privacy issues to consider.

[TSMSTSA]

The bathroom door system seems doable enough. I'm not sure what the second entails. " a teacher could scan their NFC card and the main office would be notified with an alarm" ... what exactly does that mean?

Dave

We currently do not have an emergency system in our classrooms except the phone, we were thinking some kind of reader where in an emergency system the teacher would just need to run their card over the reader and the office would be notified.

[TSMSTSA]

These are great ideas and undoubtedly can be accomplished (assuming the kid's project is allowed to connect to the school's internet portal).

If this is just a demo project, it sounds fun.

A long-range concern is that if they build it and it goes into use, who is going to do maintenance to keep it running? Door locks will wear out or break. Internet services come and go.

Since it's a school-based system with access to personal information, there are information privacy issues to consider.

Right now, it is a demo project. At some point, if they can get it up and running, I would like them to take it to the school board for further consideration and then all of the the things you mentioned and more would have to be taken into account. I am just not sure where to even begin with helping them know what components to start with.

[T_Mo]

Does the school have WiFi? Notifications would be most easily accomplished by using WiFi to send an email to the office.

[T_Mo]

What age group are the students? Do they have computer programming skills?

[TSMSTSA]

The school does have wifi and the kids do have computer programming skills. We are all learning electronics together. This is seventh and eighth grade kids who are gifted and/or willing and want to learn extra things. They come in to work with me not only after school but also on Saturday mornings and will come in every morning through the month of June to work on items before our competition. They make teaching fun because they are always challenging and pushing me to do and learn more with them :-D

[T_Mo]

Sounds like a STEM program. I'm a judge/referee for some robotics activities, so I'm aware how important and useful these additional challenges are.

Just an outline of how you could get started on the door lock. I haven't looked in detail at all of the interconnects. The same core tech could be used for the other application (they're essentially the same but without the door lock).

STEMMA QT connectors on the Adafruit products are very handy for interconnects, but not all of the modules support them. So some hand wiring may be required. Tip: STEMMA and STEMMA QT connectors are different sizes. Will not connect to each other.

You'll need some sort of electrical door lock. For an initial demo, maybe get a $15 12V DC operated solenoid lock for a filing cabinet. This saves you from having to get permission to modify a real bathroom door and avoids asking facilities to provide electrical power to it. They're listed on Amazon.

An actual electrical door lock will be anywhere from $50 to $250. A strike-plate lock mounts to the door frame, rather than the door. But might need AC power.

You'll need an NFC reader. Adafruit has one (it's an RFID controller). ID: 364. About $35. Interfaces via I2C.

You'll need a CPU to connect it to. Maybe one of the RP2040 boards with built-in WiFi. Such as a Raspberry Pi Pico W (Adafruit, around $6). Most of the CPU boards have I2C support. This one doesn't have STEMMA ports built-in.

For easier debugging, it might be worth getting a WiFi-equipped CPU module with a built-in display. The PyPortal Titano seems to work nicely. It includes some connectors for IO.

You'll need some sort of power transistor to control the lock - like a MOSFET driver. ID: 5648 (about $4) looks worth exploring.

Install CircuitPython on the CPU, go through some of the tutorials, and it should be feasible to get running fairly quickly.

[TSMSTSA]

Thank you so much!! Yes, it is for Technology Student Association (TSA)

I will look into all of this, sounds doable. I appreciate the direction to look into!!

[T_Mo]

I'm happy to answer questions or give guidance, if the team needs any help.

[Timeline]

Sounds like interesting ideas. A few random thoughts.

For the door lock idea, you will want something that can unlock the door via NFC, but also works in conjunction with a standard door lock that can still be open by other means such as a key. Because of safety concerns and emergency access, your NFC activated lock can not be a seperate lock not physically accessible from the outside. So basically, and you can buy these for your home already, you want a lock where a key, a knob from the inside, and an NFC activated actuator (motor, solenoid, etc.) all operate the same locking mechanism. If your kids only need to demonstrate the concept initially, it might be cheaper to simply note this in a presentation and then demonstrate a simpler mock up of showing a motor turning a lock upon NFC presence without having to spend $200+ for a real door lock.

Second thought to add to your lists of "features". If a student is already in the bathroom, do you have to keep other students out assuming a single user bathroom? If so, you will need to keep other students from being able to accidentally walk in on them. Which means you need some way to indicate when someone leaves and the bathroom is available again. This is where you have to consider what is actually practical. Having them scan to get back out again of course solves the problem but it isn't very practical in the real world. So something for your team to think about.

As to the emergency button idea. Most of the time NFC tags are just used as triggers anyway. They don't hold much data. A phone or a microcontroller with an NFC reader would see the NFC, perhaps verify a short code, and then do the heavy lifting to do something. I assume the teachers all have a standard RFIC capable cards already and that is what you propose they will use for this? Is this a card used to access the building as well? If so, it may be a different frequency for those than you have on your phone for payments, contactless credit cards, NFC tags you can buy online, and the NFC reader/writer sold here which usually are RFID systems all running at 13.56 MHz. Building access systems may be a completely different frequency and system. For example, I use NFC tags for various things with my phone but my phone doesn't register my RFID work badge I use for access to the building.

Quick check is take your teacher access card and try and scan it with an NFC capable phone. If it responds (vibrates, makes a noise etc) even if it doesn't do anything then you are part way there. You can sanity check that your phone is working, if the badge doesn't register, by scanning one of your credit cards that is "contactless" capable. Touch your NFC capable phone to it and it should momentarily indicate it sees a "tag". Who ever runs your schools access system can probably tell you what system they use and the types/frequency of RFID cards.

[TSMSTSA]

Thank you so much! We do have cards that we scan and punch a code to enter the building. We were trying to come up with something that would act almost like a panic button to notify the office. Right now we have to go to the phone and dial the office, which in a true emergency is a lot. Also it would be nice to have something in areas where there are not phones, like large storage closets or even the bathrooms. We are open to suggestions. Everything is for demonstration purposes only. If we can get things to work, I would then like to have the kids pitch their ideas to the school board, although again as a demo idea.

[TSMSTSA]

I'm happy to answer questions or give guidance, if the team needs any help.

Thank you so much! It means a lot and we greatly appreciate it!!