Arduino Tutorial #10: Arduino to Arduino I2C

Today, we continue with the second part of the Arduino I2C communication tutorial, using I2C to communicate between two Arduinos.

You can find the code in today's episode here:

Have a question you'd like answered, now you can email me directly at:
Or post your suggestion for a future video below.

[MicheleHjorleifsson]

I just want to say thanks for this video I've been struggling with i2c for sending text back and forth for two days and this is simple and works perfect

[SnookerUSF]

Fantastic Tutorial....best explanation I have seen on YouTube or anywhere for Arduino2Arduino I2C.

Thanks for your efforts.

[KillingChonk]

Thanks for the swift feedback. I'll have another crack at that today and see how I get on. The project is to profile ambient intensities of UVA-B-C and the V and B optical bands at increasing altitudes out to around 35 km. So the project consists of 5 photo diodes, a mini SD data logger, an RTC time stamping system and a tri-axial GPS unit. So I have all but the GPS working and tested on one arduino uno and am looking at I2C capability as the next phase is miniaturisation.

[billfield]

Excellent subject matter. I'll refer to this video regularly. With a like and subscribe, I hope to see more great vids.

[kevheys]

Great Tutorial. Easy explanations and was able to follow exactly step by step. Great Job!

[binamghimire]

thanks for the support but i pull it off. the error was quite weird though..i erased the whole thing and wrote it again..it worked!

Keep posting new videos !!.nice work!!!!

[carbine]

Love the "low disk space" notification. Great video. Thank you!

[jackbyers]

Thank you Human Hard Drive, This is very helpful.

[haydenoverseas]

legend! Thanks for the clear and concise tutorials... 

[sebastiancacerespinzon]

Thank you so much you help me a lot, excellent video, 10/10

[SanjaySingh-pnuc]

very nice explanation... this helped me alot in my project, THANKS...

[Jenachy]

Can anyone think of any reason why I cannot get my setup to work? I have connected everything identically and typed in the code exactly like in the video, but the slave board does not respond when I type H or L in the serial monitor on the master. I have also tried going from A4 and A5 to the same on both boards, as well as using the dedicated SDA and SCL pins. I can't tell if it's the master not sending the Wire data to the slave, or the slave not parsing the data.

[AmitKumar-fgqr]

You are the Bucky Roberts of electronics 😉

[KillingChonk]

The final build is to be mounted into a small box 5x5x5 cm for attachment to the stratospheric riser. So its looking like arduino nanos or another of the of the smaller ones may work nicely, minimal effort. The first prototype was with some ancient micro controller I found in a draw at the research institute. but I had to program those from the ground up with C++. The arduino system seems slightly more accessible.

[roygevers]

Thanks for this clear tutorial. You've really helped me a lot!

[kasekuchentv]

Really nice and really helpfull. Keep making videos please.

[kenfranco]

Can you use the "INPUT_PULLUP" command instead of the two external 4.7k pull up resistors ?

[coxsj]

Great stuff, thanks for putting these together!!!

[humanHardDrive]

I tie the two together so that a slight change in the voltage of one, will be balanced out by the other's remaining constant. Thus ensuring safe communication.

[pietmatsobane]

Thanks Alot . . . really helped me big time