2.3.4 or 5 arduino to communicate??

Hi Guys.

I really need some suggestions here.

I currently building an scaleable platform. the platform can consist of 1,2,3,4 or 5 units.

each unit consists of two dc motors (conveyor belt and vibrator both speed regulated) and 2 photosensors (digital input).

the units are controlled from a industrial userinterface that runs Modbus tcp.

from the interface the operator choose a recipe, a recipe contains specific parameters for each units that needs to be "downloaded" to each unit before system starts.One of the parameters are how many items the units need to count before stopping and waiting for next start. next start is when all units has done the number of counts.

My idea was to use a arduino uno + Ethernet shield + motor shield for each unit.

My concern is now, that with a arduino in each unit i need 1,2,3,4 or 5 ethernet connections to my userinterface og then a script two handle the feedback from each device.

What i really wanted is an extra arduino as master unit, that reads and writes data to each Units and then two the userinterface...?

any of you guys knows about stability and my options two communicate from 5 arduinos to 1 master?

any suggestions are valueble :slight_smile:


How far apart are the units?

Will all 5 units always be connected, but perhaps only 3 of them are needed for one job?
Will there be a different number of units connected at different times?

If they are NOT all connected and supposing there are only 3 connected will they always be units 1, 2 and 3 or might they be, for example, 2,3 and 5 on one occasion and 1, 3 and 4 on another occasion?

My first thought is to use nRF24L01+ 2.4GHz transceivers to communicate between the devices. You could have one as master sending data to each of 5 others in turn. Your program could easily include arrangements to ignore missing units.