Megadoor

Creator: hfuller Status: NFC Auth Implimented Born On: 17:28, 23 February 2016 (CST) Last Updated: 00:17, 26 February 2016 (CDT)

Overview

"I don't even know how this happened." - ctag

We're making yet another door auth system. This one will use microcontrollers and NFC.

Hardware

ATmega DIP Pin	Arduino Pin	Function/Connection
15	D9	Door Unlock Transistor
28	A5	NFC -> SCL
27	A4	NFC -> SDA
12	D6	NFC -> IRQ
11	D5	NFC -> RST

Software

Oh boy.

USB

SIAM32 USB HC

A fascinating student project to implement USB Host Control for Atmega32 systems.

With some help from friends on IRC, the code compiles, but is in somewhat bad shape, and only targets atmega32 and not atmega328p which is what we have.

USB Host Shield

We could buy a USB Shield. It feels like cheating, but is also the most feasible option right now. Also kinda pricey.

https://github.com/felis/USB_Host_Shield_2.0

https://www.circuitsathome.com/products-page/arduino-shields

USB Host Library

We could try one of the USB software libraries for the ATmega328 line of controllers. These all seem to target the chip as the downstream device, rather than the Host Controller.

https://www.obdev.at/products/vusb/index.html

http://www.fourwalledcubicle.com/LUFA.php

https://dicks.home.xs4all.nl/avr/usbtiny/

AT90USBKEY2

We could buy a board specifically designed for USB Host development. Compatible with the LUFA library listed above. This could either replace the atmega328p, or work ancillary to it.

http://www.digikey.com/product-search/en/programmers-development-systems/evaluation-and-demonstration-boards-and-kits/2622039?k=AT90USB647