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glossary:glossary_r [2017/02/16 10:08]
WortingUK [Raspberry Pi]
glossary:glossary_r [2019/11/12 01:51]
Bob Vetterlein [RFID]
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 [[https://www.raspberrypi.org/|RASPBERRY PI FOUNDATION]] provide low-cost, high-performance computers that people use to learn, solve problems and have fun.  [[https://www.raspberrypi.org/|RASPBERRY PI FOUNDATION]] provide low-cost, high-performance computers that people use to learn, solve problems and have fun. 
-Two current models of single board computer... 
  
-Raspberry Pi Zero (aka Pi0) +Two current models of single board computer running LINUX based system with several development environments...
  
-1 GHz single-core CPU, 512 MB RAM, HDMI, micro USB and 40 pin GPIO (~ £4)+Pi Zero (aka Pi0)  
 + 1 GHz single-core CPU, 512 MB RAM, HDMI, USB and 40 pin GPIO (~ £4)
  
-Raspberry Pi 3 B (aka Pi3) +Pi 3 B (aka Pi3) 
- + 1.2 GHz quad-core CPU, 1 GB RAM, Ethernet, Wireless, Bluetooth, HDMI, 4 x USB and 40 pin GPIO (~ £35)
-1.2 GHz quad-core CPU, 1 GB RAM, Ethernet, Wireless, Bluetooth, HDMI, 4 x USB and 40 pin GPIO (~ £35)+
  
  
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 [[http://en.wikipedia.org/wiki/RFID|Wikipedea article]]\\  [[http://en.wikipedia.org/wiki/RFID|Wikipedea article]]\\ 
 [[glossary:thomasrfid|MERG Demonstration]]\\  [[glossary:thomasrfid|MERG Demonstration]]\\ 
 +**MERG RFID systems**\\ 
 +The tags generally used in MERG RFID systems have a 40 bit ID number, that is 5 bytes, when transmitted there is then a sixth byte added which is a checksum for data integrity. The tag readers transmit the data over a serial link using [[glossary_h#ascii_hex|ASCII Hex]]. The start of a message is STX <0x02> this is followed by the 12 ASCII Hex characters of the data plus checksum, some readers then send LF <0x0A> CR <0x0D>, and finally ETX <0x03>. This makes a message of either 14 or 16 bytes in total.\\ 
 +The MERG Concentrator replaces the STX with a reader identification letter, A to H or I to P. For CBUS the incoming data is converted back to its original 5 bytes and checked against the checksum. These 5 bytes are then transmitted as bytes 3 to 7 of an 8 byte message. <Opcode><DN/NN Hi><DN/NN Lo><data0><data1><data2><data3><data4>
 ===== Risk assessment ====== ===== Risk assessment ======
  
glossary/glossary_r.txt · Last modified: 2020/03/12 05:27 by michael_smith