Main Site Documentation

WiFi, Bluetooth or XBee


#1

Is XBee the best way for one Gadgeteer board to communicate real time with another Gadgeteer board? Or is there a better real time way to do this using the WiFi or Bluetooth modules?


#2

“Best” way depends on your requirements.

Range, costs and throughput.

Regarding range:

Long distance (KMs or Mile+) - XBee
Short range - Bluetooth, SFF or BLE
Medium range - Community member Justin has a Serial Pipe in the creations.
Wifi works as well short to medium, but requires an AP.


#3

Thanks Mhectorgato,

Range is short (a few feet), small amount of data, but response must quick - 20 to 30 times per second.

Can the Bluetooth SPP module be used for two way between Gadgeteer boards?


#4

Hi,
there should be no problems to use the Bluetooth SPP module in a two way connection between to gadgeteer boards.
http://www.readbag.com/elmicro-files-seeedstudio-btbee-setup
I think, that a response time of 50 ms (20 times per second) can be reached in normal operation but you must consider the effect of the Garbage Collector. Certainly some other members of the forum know better than I, which delay time has to be considered. But this is not only the problem with a Bluetooth connection, it is a problem of the managed code.
In the forum there were, as far as I know, no examples where the Bluetooth module was operated in Master-mode. So I do not know if the driver works correctly in master-mode.
What are you going to do with the two connected Gadgeteer boards?
Kind regards
Roland


#5

Hey Ro,

I have multiple (3 or more) autonomous drive units (each with at least a gyro, a compass, ESCs and a control board) that have to move together (swarm) at high speed to reach an exact waypoint.

The location of the waypoint becomes more accurately known as they move, requiring the coordinates of the waypoint to be updated at a high frequency.

Can you force a GC in .net micro? Best to do it in between waypoints if possible.

Does anyone know if the Bluetooth module can work in master-mode?

Thanks,

Michael


#6

Interesting, …hope these beasts wont attack me.
Do you want that each unit can communicate with each other unit? Usually one Bluetooth module is paired with one other bluetooth device. I dont know if it is possible that one module can talk to more than one other module. I guess that they can not.
The module can work in master-mode. I do not know if the driver class was tested for master mode.


#7

The RF Pipe from (board member) Justin may work for you as well

https://www.ghielectronics.com/community/forum/topic?id=11783&page=1

Any message broadcasted, will be received by all nodes.

It effectively is a serial connection to the other nodes. Communication to the module is over a U socket and connects at 9600 baud and between modules at 2.4Ghz RF.

https://www.ghielectronics.com/community/creations/entry/12


#8
Microsoft.SPOT.Debug.GC(true);