kranenborg
Senior Member
Dear Forum members,
After more than a year of on-and-off work I am now able to present a complete specification as well as a tested implementation of a true two-wire combined power/data network of PICAXE nodes (one master, one or more slaves) that supports bi-directional communications between processes distributed over any number of nodes.
I would like to submit it now to the Forum for a thorough review/discussion for two reasons:
- The discussions on this forum have contributed greatly to the development of the network
- The resulting documentation and implementation may provide some value in return to many PICAXE users.
The network concept has the following characteristics:
- Power and data are distributed over just two wires that are interchangeable; furthermore, only the master node needs a power source,
- All nodes are similar in that they catch all network messages and process them in a equal fashion,
- The network can be realized (and has been successfully tested !) in a practical in-house setting spanning several tenths of meters,
- The protocol is efficient in that it allows small microcontrollers (PICAXE-08M) to implement both functional behavior as well as a full-fledged network stack (a compete network stack on the 08M requires only 94 bytes out of 256)
I have put great effort in creating proper documentation; I hope some forum members are willing to review it (and perhaps even test it by building their own implementation). Reactions are most welcome.
A successful test has been performed for an in-house network between two nodes 20 meters apart. Of course eventually a more thorough test is needed.
In my opinion the network concept is a proper demonstration of the power of the PICAXE concept.
All information is available via the following link:
http://www.kranenborg.org/ee/picaxe/twowirenetwork.htm
Best regards
Jurjen Kranenborg
http://www.kranenborg.org/jurjen
Edited by - kranenborg on 19/10/2006 21:54:45
After more than a year of on-and-off work I am now able to present a complete specification as well as a tested implementation of a true two-wire combined power/data network of PICAXE nodes (one master, one or more slaves) that supports bi-directional communications between processes distributed over any number of nodes.
I would like to submit it now to the Forum for a thorough review/discussion for two reasons:
- The discussions on this forum have contributed greatly to the development of the network
- The resulting documentation and implementation may provide some value in return to many PICAXE users.
The network concept has the following characteristics:
- Power and data are distributed over just two wires that are interchangeable; furthermore, only the master node needs a power source,
- All nodes are similar in that they catch all network messages and process them in a equal fashion,
- The network can be realized (and has been successfully tested !) in a practical in-house setting spanning several tenths of meters,
- The protocol is efficient in that it allows small microcontrollers (PICAXE-08M) to implement both functional behavior as well as a full-fledged network stack (a compete network stack on the 08M requires only 94 bytes out of 256)
I have put great effort in creating proper documentation; I hope some forum members are willing to review it (and perhaps even test it by building their own implementation). Reactions are most welcome.
A successful test has been performed for an in-house network between two nodes 20 meters apart. Of course eventually a more thorough test is needed.
In my opinion the network concept is a proper demonstration of the power of the PICAXE concept.
All information is available via the following link:
http://www.kranenborg.org/ee/picaxe/twowirenetwork.htm
Best regards
Jurjen Kranenborg
http://www.kranenborg.org/jurjen
Edited by - kranenborg on 19/10/2006 21:54:45