Tutorial Python

After Hours Programming was a very good experience of learning Python basics. http://www.afterhoursprogramming.com/tutorial/Python/Overview/

Wireless Modules

Recently I found this word press blog describing about different Rf modules and which was useful to me.

IEC1107 mode D

Data exchange is unidirectional in protocol mode D and permits readout only. The information flows from the tariff device to the HHU. Data transmission is initiated, for example by operating a push button or other  sensor on the tariff device.

The protocol mode used by the tariff device is indicated to the HHU by the identification message. Protocol modes A to D are identified by the baud rate identification character ,while protocol mode E is identified by an escape sequence.


Protocol mode B (with baud rate changeover, without acknowledgement/option select message)

Protocol mode C and protocol mode E (with baud rate changeover, with acknowledgement / option select message or other protocols)