Advice regarding a project

Hello everyone,

I would be very grateful for some advice regarding a project that I am working on. I am trying to build a hardware prototype that would be used to display information about schedules. I work at a university and we currently print out the room schedules on the friday and then someone goes around putting them on the doors of the rooms.I believe this is wasteful since the university has over 300 odd rooms and the papers schedules are pretty useless since the schedules change and they don’t get printed ( for e.g. a class might be scheduled for a thursday this week and booked on the monday … it won’t get printed since the schedule was made up on the previous friday) and the papers are in any case only used for the week.

Instead I was wondering if we could use a small LCD display to display what class or meeting is being held at the current time but also show the weekly schedule via a touch screen interface. IF possible I would also like the touchscreen to let students see the lecturer associated with the class and a brief summary. I have little or no hardware experience though I am a decent .NET programmer. I was wondering if the FEZ Spider would do the job as far as the hardware is concerned for this project? Ideally I would like the hardware to have Wifi capability to connect to our database and retrieve the timetable, a 7 inch touch screen to display the weekly timetable, nfc reader to let the students login using their ID cards. Power connections would be another issue since the panels would be attached to the doors or the adjoining wall. Is there any way I could use a solar panel to power the device? Is this project even feasible? What components would I need to make this work? I have looked at some of the components from ADAfruit like the Solar LiPo ( and the PN532 Board for NFC. What I can’t figure out is if they would work with FEZ Spider. Also I am not sure if I can get a bigger touchscreen panel instead of the included one?

I would very much appreciate any advice at all. As I mentioned I am a complete noob when it comes to hardware and I am pretty much doing this in my own time and I don’t have a huge R&D budget otherwise I would have hired an experienced electronics engineer to build a prototype for me.

Thank You



@ Alex15

Welcome to the community!

The FEZ Spider would work pretty well for prototyping something like this.

The pieces that aren’t currently there, in terms of what you’re looking for are the screen (there isn’t currently a 7" touch screen for Gadgeteer, the GHI T35 display is the largest available at present) and the NFC reader.

If you get the Extender module, you may be able to use that to wire up a stand-alone NFC reader, but I don’t know enough about those readers to tell you which particular interface you’d need to use. Best bet to start with is to get an extender module, solder header pins on it, and get yourself a breadboard. Connect the extender to the breadboard, and then you can test your various components out without having to solder them permanently.

A wifi module is available, so network comms isn’t a big issue. Not sure that solar is practical indoors. I don’t have much experience with solar, but my impression is that to get decent power you really need direct sunlight. Perhaps @ ransomhall, who’s played with that stuff a bit more, could comment on that aspect.

Do keep in mind that the larger the screen you use, the more power the units will require, and likewise, wifi tends to be more power hungry than wired networking.

Is there any way to mount the units next to the doors, rather than on them? That would potentially allow you to run both power and network cables, and save you some trouble and money (the wifi module is significantly more expensive than the ethernet module).

A list of available modules is here:

If you think you’re going to be doing a fair amount of prototyping, I would definitely get several extenders. They’re very useful when you need to go outside the Gadgeteer box and bring in additional components, or design your own modules.

@ alex15 - sounds like a pretty involved project! As @ devhammer said, Gadgeteer is a great prototyping platform for this kind of thing. Some things to consider:

  1. Wireless - if your data is updated infrequently (as it sounds) you might want to go with serial RF in the form of something like an XBee. Instead of $100 per module, it would be more like $35. Also, with these you can set up a mesh network to provide redundancy. There are also other low speed serial wireless options that are even more reasonable.

  2. Solar - can’t do it indoors. The conundrum with solar on a project with a screen is the solar needs to be in direct sunlight to really work well, which makes most screens impossible to read. For something that is always on like this, you’ll need to go with an AC adapter.

  3. 7" display is NOT small for microcontroller projects like this and are power and processor intensive to run. We’re not talking tablet here.

  4. RFID/NFC. No module available yet. However, there are microcontroller compatible boards available. I just got my hands on the NFC board Adafruit sells. It can be easily interfaced with a gadgeteer and some custom wiring. The board uses SPI to communicate with a microcontroller. I doubt you really need NFC just for a login. RFID will work just fine. NFC has yet to really break loose as a technology, so you’ll tend to be cut on this bleeding edge. RFID is very well established and there are many more hardware options.

  5. As a .NET developer, you’ll find the software end of this platform a breeze to pick up. It takes a bit to wade through the specifics of the hardware, but there is a boatload of well documented info in places like this. The users in this forum are highly skilled and very willing to help.

7" is almost ready. We have been evaluating many and may have final decision soon.

Fresh blog post on the subject (via Facebook):

RFID (Parallax RFID Card Reader) with Gadgeteer.

Couple different challenges here. Power, economics, and getting it to done.

  1. Power will be an issue. Battery and solar not really on option. So that means a hard install in the wall and electrician time. If you had to pull power anyway, it would be better to pull ethernet at same time and remove issues with wireless.
  2. Economics. This can take you all over the map. Your at least at $500/unit and that is guessing $200 bucks for the display and maybe more. 15-20K for the units plus labor and mounting hardware/covers. Something like a windows tablet would almost make more sense at it has everything you need in an already condensed package. Each room? I am not sure this really needs to be on each door. What about a single kiosk every 10 rooms or every hallway? Lot easier and cheaper to pull services to fewer units.
  3. Touch. Not sure you really need. In fact, you may want to avoid 1000 fingers and pens touching the screen directly daily and risking a lot of breakage. I think you could get 90% of the function with a button (or two) and a normal display behind an acrylic abrasion resistant sheeting.

Another idea is to flip the whole concept. Leverage the student cells phones for the hardware (they all have an iphone or droid and text non stop these days). Add a QR Code barcode and short url under that on a door plate. They can then scan the QR Code from their iphones/androids and browse right to a url specific to the room. Then the whole issue is reduced to a simple web app. Could then also type in student code into site for specific stuff on their schedule. Another possible advantage is could work for visually impaired (site could speak course name). Could also add QR Codes at key locations to serve as “live” directions around the campus, lunch menu, etc. Maybe not as flashy as 300 monitors, but much Kaizen and broader reach as a general solution.

Of course I think Gadgeteer should run the world… However, this would be a perfect project for Raspberry Pi and a cheap monitor. If the Pi is ever actually sold…

William has it right. A qr code for each room + a webservice is the way to go. You don’t want to create 300 devices. students can use their phone or visit the webpage manually from virtually anywhere.

(and a raspberry pi needs a hdmi panel for display)

This is exactly the project I’m currently busy with at work for our new corporate offices. In fact, if there are people that want to collaborate I’d be glad to involve you! I’m looking for a developer to help with the Exchange integration and Android app (more on that later).

I did a LOT of research on this. Here are some of your options:

  1. Use a commercial system like the Crestron RoomView. Of course this is the ultimate convenience - but they are very expensive and the screen is actually rather small (4.3").

  2. Use a low cost controller like a Fez Panda II and Ethernet Shield with an intelligent display like the ones from 4D Systems - Biggest problem is the display is small and the cost is high for the size. Top marks for cool factor and learning something though.

  3. Use a graphics capable controller like the Spider with a large display. The problem here is cost. If you add the components together you get to $500+ before you have anything decent to hang on the wall.

  4. Use a digital photo frame and feed it with pictures from a website. The pictures are “rendered” by your software that is connected to the scheduling system. The problem here is photo frames with network connectivity are pretty expensive and few of them than take a photo feed from your own source. They want to go to Picasa or Kodak or whoever wants to lock you in to a service. I did some initial work on seeing if a Wifi SD card could work with the cheaper frames but didn’t really take it much further.

  5. Use a commercial off the shelf 15" LCD screen with a Raspberry Pi. This is not a bad combination - once the Pi is availlable.

  6. By far the cheapest and most viable option is to use a $80 7" Android tablet with Wifi. Just run your own app on there to display your feed from the server. Sorry - it is not NETMF (and that is why I asked if NETMF can be ported to these devices). Also Windows tablets are at least 4 times the price - presumably because of the licensing costs. There’s just no way that any self-developed solution is going to compete with what are in those babies.

For power the most convenient is Power Over Ethernet. Solar won’t work because you’ll need a big panel to match the power demand.

I must say I like the QR Code idea. In our setting (corporate boardrooms) we want something to permanently display, but in the university setting a self-help solution could be great. Maybe use augmented reality so when you view the sign through your phone, it super-imposes the data on the screen. It would be like looking through a data window to reveal the secrets of your next class :slight_smile:

Hello everyone!

Thank you so much for your kind input and advice.

As I mentioned this is a pet project of mine that I am working on with the hope that the university will approve and turn into a practical application.

There are alternative ARM based systems which have a larger screen but they wouldn’t be able to run .NET MF.

The Rasberry Pi is a great idea and I am going to see if I can do something with it. WinCE runs on ARM based processors so I am hoping that someone will port WinCE on to Rasberry Pi allowing me to work on .NET MF or .NET CF

The issues with Power and my intent to use Solar panels is the same. The panels are meant to be mounted on the door ( not even the adjoining wall) and as such dragging any kind of cables into the equation is an issue. I did consider power over Ethernet but this mean working with cables again. I want to avoid it if I can. A colleague has pointed to me to a high quality solar panel which can absorb light from ordinary household light bulbs and make use of it. Alternatively we could use rechargeable batteries I guess as long as the device doesn’t run out juice for at least a month or so.

The QR idea may not work for us since not all students have a smart phone , and not everyone would know how to use a QR code. Some of our older more distinguished academics are still hanging on their Nokia 3300 candy bar phones. Anyway … we want the students to be able to glance at the door and have the information they need. Most students would not bother pulling up their phone to look up the QR code. They would just skip the class instead. I know that’s lazy and pathetic … but hey that’s what I did when I was a student. If I didn’t find the right room in the first 5 minutes I would just skip the class (unless it was a really important class)

The reason we intend to use RFID/NFC is because we would also like to the use the panels as an attendance monitoring device. The students will be expected to tap their ID cards before walking in to the class room. The data is just sent over to a web service which then add to their attendance record on the student management system.

I am going to suggest the QR code to my boss but I would still like to work on the project as a hobby to see what I can come up with. I am going to order the Fez spider with the TH35 screen for now and see what I can do with it. I’ll get the RFID/NFC module and the wireless module as well. I’ll keep updating this with any progress I make.

But in the meantime if anyone has a suggestion or perhaps a way to solve the power and the screen size issue, I would be very grateful for the advice.

Thank you again for all your kind responses.


Hi, do you know any high power RFID reader/writer to read a tag embedded under 30 cm the Asphalt Concrete Road and What tag can be used in this situation?

What about a Fez Mini with a monochrome 128x64 display. It will be large enough to see at some distance but very importantly, it uses very little power. If you use a reflective one you don’t need a backlight and solar should be able to do it. These displays will hold the image while the processor hibernates so it could work.

A big 2x20 character lcd could also work. Even easier.

The RFID reader I use draws 30mA and reads up to about 20cm.

For comms, maybe use the Nordic or Radiometrix or Zigbee modules. Wifi is cool but expensive and power hungry. These things can chat on half electrons.

I think the big question is not on what Fez to use to read the RFID reader, but what RFID reader you would use. Tsu’s criteria is basically that it must be embedded (30cm) in concrete and be able to read the RFID tag that is in (I would assume) a car or truck.

I think to answer a question like that oyu’re probably going to have to find a RFID specialist forum, because that seems very specialised to me :slight_smile:

My answer was meant for Alex15. Tsu’s requirement is a whole different matter.

RFID’s distance is limited because it needs to provide power by inductance to the tag first before the tag will transmit. Getting the power delivered through 30cm concrete will be hard. You need a very big coil and a powerful drive circuit.

Working with active tags might be different. These tags have a built in battery and they can work over several meters so the concrete might not be such a big factor.

realiser : Thank you very much for your response. I originally intended to use a a touchscreen to allow users to interact with the terminal and view the timetable for the room for the entire week or the month.

Seeing that it would be near impossible to use solar cells in this scenario (it’s not cost effective after having spoken to someone from Sonelis - They make custom Solar Cells ), I have now worked around a restriction. I now have PoE available. Would the Fez Spider work in this scenario? I would still want the RFID and a reasonably sized Touch panel.


Fez Spider could be made to work. There’s only one PoE module for Gadgeteer that I’m aware of, and anytime soon Architect will be along to spruik it, as he created it :slight_smile:

Personally, the Spider would be a great kit for you to build a prototype with to show how it works (because it has simple plug-and-play capability) but the Fez Cobra has the same core module and can even be bought with a housing that would be almost 100% perfect for your use in the final location. That’s what I would look at for your final solution.

Hello Brett,

Interesting. Since this is just for a prototype would I be better off with Fez Cobra then? Not that either the Fez Spider starter kit or Fez cobra are in stock…

How easy (or hard) would it be to add the additional modules to Fez Cobra inside the casing?


Either way you need a PoE module. There is a Gadgeteer one that Architect has, so that’s a good thing. I am sure there’s a way to do PoE for Cobra but I don’t know of any actual solution

Either way you need an RFID reader. With Gadgeteer it’d be easy to connect a Gadgeteer RFID reader to the Spider. With the Cobra you’d need to wire/solder the appropriate pins into the device - plus you’re going to need to put the aerial away from the display too, in which ever scenario you use, which may again require a different enclosure or a different enclosure enclosing the Cobra OEM enclosure (whoa, recursion). One of the other RFID challenges is that nobody has actually created an RFID reader specific to Gadgeteer that I have found, so you’re still going to need to use an Extender module and a soldering iron (so little different tothe Cobra scenario in my view).

Either way you need a touch display. The Gadgeteer standard display is the 3.5" one, and is resistive touch (as I understand). The Cobra can be bought with a 4.2" resistive touch display, that still fits in the Cobra OEM case.

Any other sensors you’ve thought about the need for? Any other options you might want?

The idea behind Gadgeteer was rapid hardware prototyping through the standard connection patterns, and sensors/devices that used those connections. One of the “challenges” we’ve discussed before is what happens once you move away from the prototype stage and you need to actually make something for permanent installation. Sure you can buy lots of Gadgeteer boards and sensors, but the cost of that is typically prohibitive compared to buying bare-bones and creating something custom for your needs. To a degree that’s also the case with Cobra, it can be cheaper if you have large quantities of devices to make, to custom design and build a board that takes an EMX module and only has the connections you need, in a form that you want - but you may find that it requires a whole different set of skills as well! So if you are really focussing in on just doing a one-off prototype to prove your concept works before taking it any further, and you don’t have ready access to a hardware guy to assist, then Spider will remove some of those challenges out of the equation for you. Sorry, I can’t answer the ultimate question for you beacuse only you know your true soldering iron skills and your access to other people to assist - you’ll get a great platform if you chose either one, and you’ll get great virtual assistance from us all here, but you might still need someone on the ground to assist. Speaking of, where abouts are you from ?

Hello Brett,

Thank you for that detailed reply!

I think I will stick to Fez Spider. While I have handled hardware and have done a wee bit of soldering, I am by no means an expert and I would avoid it if I can.

For the RFID part would this component work in your opinion?

I am also looking at this one AND

I would like a bigger screen but I am happy enough to build the prototype with the T35 for now. Are there any capacitive screens available that work with Fez Spider? I understand that the cost would probably be quite a bit higher.

Well I don’t foresee the need for any other sensors. Like I said the entire device will be mounted on a wall or a door.

I don’t have access to any hardware experts here. So I am on my own at the moment though I might advertise around and seek the assistance from a hardware engineer locally if I get stuck, though I don’t usually know when to quit … :slight_smile: So I am hoping I might be able to get this off the ground on my own.

I am from Liverpool , UK .

Thank you once again. You have been very kind. I will try and post a list of all the components I am going to order tomorrow. I would be very grateful if someone could have a look and let me know if I am missing something.