What is the fastest wire communication between two Arduino?

Good morning.

I need to communicate by wire two Arduino boards that are next to each other.

The first one is reading the pulses of an encoder at the maximum speed that the Arduino gives. The second will catch the value of the first to send it by RF, show it on a screen, etc.

I need to know the fastest way to communicate between two boards (SPI, I2C, Serial, etc). The value to read is an 8-bit number, I'm thinking of using 8 pins to make a parallel communication that's the same as fast, right?

Thanks a lot.

Pulsar79:
Good morning.

I need to communicate by wire two Arduino boards that are next to each other.

The first one is reading the pulses of an encoder at the maximum speed that the Arduino gives. The second will catch the value of the first to send it by RF, show it on a screen, etc.

I need to know the fastest way to communicate between two boards (SPI, I2C, Serial, etc). The value to read is an 8-bit number, I'm thinking of using 8 pins to make a parallel communication that's the same as fast, right?

Thanks a lot.

Assuming u will be using direct port manipulation then I should think that parallel communication would be the fastest.

in terms of serial comms, SPI probably is the fastest though not very reliable when using it between 2 arduinos I have found. next would be hardware serial comms which can go up to 2Mbps though never tried using that speed personally

Thank you.

Yes, that's what I thought, parallel communication. But just in case he didn't deserve to put so much cable.

Thank you very much for your answer.

If you can avoid the need for high-speed communication you will probably reduce the computation load on both Arduinos.

...R

sherzaad:
Assuming u will be using direct port manipulation then I should think that parallel communication would be the fastest.

in terms of serial comms, SPI probably is the fastest though not very reliable when using it between 2 arduinos I have found. next would be hardware serial comms which can go up to 2Mbps though never tried using that speed personally

In real life, you need an additional pin to tell the second Arduino there is valid data on the 8 bit parallel cable. It's called a strobe signal.

Paul