I just got into an interesting mess.

I have 3 Arduino's (Pro Mini's) and 2x Teensy's (3.1's) connected via I2C to a Raspberry Pi Master. The 2x Teensy's I2C data lines are connected via OctoBoards but that doesn't really matter since the OctoBoard maps the I2C Pin's of the Teensy to itself. I have 4k7 pullup resistors for SDA/SLC close to the master (also tried on the end - with no effect).

The Arduino's alone are super solid - no issues other than the occasionally I2C lockup when writing data.


The I2C interface has been running for over 3h with no problems.

Now as soon I add a Teensy to it, the bus locks-up and I need to completely shut down everything. Only thing I got to work was direct connection from RPI -> Teensy and even then there were sporadic detection issues.

I tried the Wire lib as well the IC2_T3 lib with no difference. Also tried with 4 different Teensy's with no difference.

Are the Teensy's not compatible with RPI?

  • That is a lot of antenna hanging around. Consider using a method that keeps the Microprocessor wires from going from computer to computer. Ground references could cause a lot of problems and would explain the problems but it is not the only possibility. Different processors have different reactions to transients. Be sure the grounds from each unit are connected together. I would expect each combination to act differently. – Gil Oct 29 '15 at 22:18

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