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nordseele / hans

OSC and MIDI over i2c for Eurorack modules ER-301, TXo, etc. i2c to MIDI for Teletype, and more...
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⚠️ RPI prevents the ER-301 from booting up normally, they need to start simultaneously #1

Closed nordseele closed 4 years ago

nordseele commented 4 years ago

⚠️ Connecting the Raspberry PI directly to the ER-301 module or even to the same i2c bus is a source of problems. If the two devices are not started simultaneously, or if the ER-301 is powered on after the RPI, the Raspberry Pi will prevent the ER-301 from starting normally.

(The ER-301 uses the bus for UART during its startup, it pulls the line down => Conflict with the RPI i2c hardware gpio)

To overcome this problem, it is prefereable to create an external circuit including two 4.7k pull-up resistors and use another set of GPIO on the Raspberry for i2c (aka. "Software i2c overlay") rather than the "hardware i2c gpio".

nordseele commented 4 years ago

An hardware solution is currently being created.

nordseele commented 4 years ago

Considered fixed with Hans hat and a software i2c bus. No work will be done for the hardware i2c bus.