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I2C Serial Communication between two Teensy 3.2

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New Member
Hi Everyone.
So I have a two teensy 3.2 boards and I would like to create a serial communication between the two.

I found a tutorial on Instructables.com: https://www.instructables.com/id/Com...-Arduinos-I2C/. However, the author uses two Arduino Uno.
I tried doing the same thing on my two teensy boards.

However nothing happens whenever I tried pushing the button on master board. Supposed to be, the led on the slave board should lit.

Could anyone help me on what connections and wiring should be done on my teensy boards?

Thank you!


Well-Known Member
Most Helpful Member
Don't know the boards but would guess you need to connect the I2C communication pins.



Active Member
Not sure about those boards, but be sure to put pull-ups on the I2C lines. Some chips may or may not have internal "weak pullups", or those may have to be enabled via configuration.
Putting in about 10k pull ups to VDD should at least stabilize the signals.

Nigel Goodwin

Super Moderator
Most Helpful Member
As suggested, you may need pullup's - I2C won't work without it they 'may' be fitted on the Uno board?, or internal).

However, I'm always rather confused why people want to use I2C to communicate between two micro's, there are MUCH easier ways, a simple serial (RS232 style) connection is always my preferred method. I2C was specifically designed to interconnect multiple IC's on PCB's, in order to reduce the number of required connections between them all - not to talk between two micros.


Active Member
This has been posted in several places but no response to actually posting the connections and programming code used. For that board, setting master and slave has different syntax and that would be my first guess assuming that the Instructable wiring was followed. See this thread, for example.
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