Congrats! (& questions)
Well done @MrStein! It's really exciting to see a project like the Keyduino in the forums go from your first prototype to backed project. Too bad it may missed the stretch goal. :( Will the antennas your going to offer be of your design? In my project planning I have a couple questions. I plan on using nfc in my car. Do you have an idea of the temperature tolerances for the boards and for the antenna? Is distance of the antenna lead a factor? If I use it as a door lock system, the antenna at least, and perhaps the board, will be closer to the exterior of the vehicle. I saw the one @johnyma22 uses. How does it hold up for you @johnyma22, and does it get very cold where you are? You wouldn't know it by the weather we've had lately (71f compared to the usual 31f at this time of year.) But it can get extremely nasty in the winter. Last year we had 9. 5 feet of snow by this time in the region. So cold will be a factor. There is a body panel on the trailing riser of my window I would use for the antenna to get a good signal.
Thanks again for sparking my imagination. My project ideas have most to do with replacing car and house keys as the nerve damage in my hands has made dealing with and using keys a PITA. ;)
Thank you! :D
We will make a update for the antenna, you will be able to buy them on EBAY ;)
First estimation: small one for 3€ and big one for 4€ (with 10cm cable). Keep you in touch.
For the temperature, really great question... we have made some stress test; voltage input,... but not temperature... A quick look with the datasheet of the 2 most sensitive components:
PN532: -35° to 85°
ATMEGA32u4: -35° to 85°
So if you don't leave in the north pole or in hell, it will be okay :)
I don't know if the temparature have an impact on the reading distance... I will search or spend some time playing with the freezer ;)
So your telling me I cant use the KeyDuino for my polar expedition??? I'm very disappointed ;-P
Nop sorry :(
But it's North-of-france approved and trust me, it's really cold and wet everydays here! :p
I know it's wet. It's basically all you guys have in terms of weather :-P
@MrStein - a curious question:
Reading distance for the large one:
cannot read the 2013 NFC ring (or at 1-2mm) but can read at more than 1.5cm for the 2016 one, don't ask me why
3/4 cm for a badge
6/12 cm for a proximity card
The large antenna behaves strangely because it's such a poor match for the NFC Rings small antenna, yeah? You're basically having to hit one of the stronger lobes to activate the inlay, rather than having it work directly as with the smaller antenna - because of the poor match between the two.
I'm just pointing this out (and doing it here because KS comments are forever) because I noticed that it says on your campaign page that "...a big external antenna, increasing the reading range by three times! "