Archive for October 16, 2011
New Designs Coming
We have been working hard on a road map for the next generation of open-source security hardware. At this stage, we are focusing on trying to make it easier for all of our collaborators to work with existing access control readers and keypads. A lot of these only support RS-485 or Wiegand format.
Since this is a volunteer effort, most of the hardware people are using for testing is donated or purchased used, often without much documentation. So our next two project goals are:
1. Wiegand/RS485 terminal block – This board will use a new pluggable 3.5mm terminal I found, and it will make hooking up test hardware much faster. Design is already done and ready to be sent out for fabrication. We will post the Eagle files when it has been built and tested.
2. An RS-485 shield for the Arduino microcontroller. RS-485 is a long-range serial protocol that is popular with alarm system and industrial equipment vendors. It can attach up to 32 devices to a single bus, has a 4,000′ range and uses differential signalling for noise-immunity. It is also fairly easy to adapt to existing serial devices, including PCs. Given the state of Arduino Ethernet, this seems like a sensible choice for attaching a variety of non-server devices. Our version of this board will provide jumpers to allow a variety of pins to be used for maximum flexibility.
Check back in the next 2 weeks for an update!
JN
October 16, 2011