The SNARC: Concept to Prototype to Product

by Lawrence Lemming Dixon

SNARC is Simple NetworkAble RFID Controller, made by Maker Lemming.

SNARC is RFID access controll system which is used with WIZ820io for logging access entry.
Lemming is maker who activates in HSBNE. The HSBNE is Brisbane’s hackerspace in Australia.
He posted the development, testing, revision and implementation of the board on his web-site, and He uploaded the SNARC for the goal fundraiser on Tindie.
But, Because His SNARC can’t be found on Tindie, I don’t know whether it is successed or not.

He started to make a simple access controll system with Arduino Board and EM1400 125KHz RFID tags. And then He had many times trial and fail to make SNARC_PTH V1.3 in order to achieve the following 4 goals

4 Goals for SNARC

• Small
• As self contained as possible
• Cheap
• Easy to implement

PCB : SNARC_PTH V1.3

He make the SNARC with only PTH parts instead of SMT parts for easy to implement as 4th goal.

Tip for WIZ820io

He discovered that there was sometimes a race condition between the micro-controller ATMega328-pu and the Ethernet module WIZ802io where upon reset or power on of the board, the reset lines of both were tied together, the ethernet module would sometimes boot up slower than the micro-controller for whatever reason. This meant that if the board lost power for some reason, or someone (inadvertently or not) hit the reset button,the board would sometimes hang hard.

For solving this problem, He controlled the RESET of WIZ820io with a GPIO of ATMega328-pu.

Learn more

Lemming’s site : http://www.lemelec.com/snarc-pth
Source open : https://github.com/LemElec/SNARC_PTH_V1.3, https://github.com/LemElec/SNARC_Demo_Code

The related article : http://www.embedds.com/simple-networkable-rfid-controller/

TAG : 201308, W5200, WIZ810io, Access Controll, SNARC