[How to do instruction] 128x64 OLED with Song Status and Spectrum Display on Raspberry Pi

[The Herb Guy]

This is what I found on the Hifiberry website:

GPIO USAGE OF HIFIBERRY BOARDS
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We do not guarantee interoperability with any other add-on card. Even if another card is not using the same GPIOs, there are many other things that might prevent interoperability. The Raspberry Pi GPIOs are not designed as a bus system (even the I2C bus can’t be simply used by multiple cards as there might or might not be the right pull-up resistors on every I2C slave).
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HIFIBERRY DAC+, DAC+ ADC, DIGI+ AND AMP+
GPIO2-3 (pins 3 and 5) are used by our products for configuration. If you are experienced with I2C, you might add other slave devices. If you a a novice, we don’t recommend this at all.
GPIOs 18-21 (pins 12, 35, 38 and 40) are used for the sound interface. You can’t use them for any other purpose.

Maybe the resistors on the display are the problem?