Hello hbecem,hbecem wrote: I tried the same idea you did and I used a max485 driver with easy transfer library using serial N°1. but no synchronisation entre surface arduino card and subsea arduino card.
Please keep in mind that the max485 and max488 are two completely different chips, and their pinout is different as well. You will want to be sure that your pin out matched the data sheet for your IC.
Assuming that you have the correct wiring, it is also important to note that the max488 allows for full duplex with out having any special code to determine which direction the data is flowing. The max485 is only half duplex and will require you to set the directing or "data flow" prior to sending any data. (or require you to double up on the circuit using a total of 4 max485 to achieve full duplex).
One method you could use to check if it is your code or the wiring is to simply bypass the max485 chip. If you connect your Arduino1 Tx to Arduino2 Rx and Arduino1 Rx to Arduino2 Rx, you should be able to transfer the data. (Correct me if I am wrong, but this direct connection is actually full duplex, so errors in your code that determine the direction of flow may not be detected in this sense...)
Anyway, I have a build night planned for tonight so I will work on cleaning up and commenting my code (specifically relating to the communication) and post that on here when it is complete.