2018-05-02 (W) ModuKey

Since the most recent version of the boards weren't available some of the changes had to be implemented ad-hoc. Pullup resistors were added to the data lines on the controller boards. It was never determined if these were necessary but they didn't hurt communication and they were part of the final design so some were installed.

Bottomside of controller board with pullup resistors on data lines

A pullup resistor was added to the RST pin of the IO expander. Communication was attempted with the board first but it was unsuccessful. This was the most likely culprit so it was the first round of debugging.

Bottomside of 4x4 IO board with pullup resistor on RST pin

After the pull resistor was installed, communication was established through the Teensy-LC. There was trouble communicating on the second I2C bus built into the Teensy. This may be a problem if many IO modules are necessary but it may be a hard limitation on the library.

Changing the I2C address on the 4x4 board with jumpers

The rest of the posts for this project have been arranged by date.

First time here?

Completed projects from year 1
Completed projects from year 2
Completed projects from year 3
Completed projects from year 4
Completed projects from year 5

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