just use one digital I/O to synchronize the Arduinos.
Since I am a beginner I don't even get how can I use a digital I/O to synchronise my arduinos. Would they be able to have shared clock?
As you haven't described what kind of system you're trying to simulate...
I am trying to simulate a sensor network. Many sensors "accelerometers" capt analog data, convert it to digital data then send it to a performant processor to make some calculations and return significant values (speed, etc). They send data via I2c.
The performant processor is the master. I am going to simulate the sensors and the data they send just to test the master algorithms. So I have log files of the measures that sensors return and I need to send them to the master. And this should be done via I2C to make it similar to the real system.
The sensors are supposed to capt and send data in high frequencies let's say every 2.5 ms. I need my arduinos to be able to respond to the master in this frequencies and also send the right data. I mean at a given time t : all arduinos should be able to have the data that corresponds to the instant t in the log file (which can be a table when each row contains the values of a given time)
I can upload on each arduino its own log file and make it parse it in the loop and just send the current value when the master asks for it. But can I really make all arduinos start parsing their files in the same time ? Being 2 ms late can cause problems later on. And can I be sure that they will function in the same speed?
That is my problem. I asked some electronic guys and they told me that there's no way and no hope to make them synchronised.
I would be more than happy if you see a solution there.