Using the plinky expander without a eurorack case does not work properly. The expander is connected to +5V, however schottky D4 prevents this +5V rail from powering the TPS61040 which in turn generates the +12V and -12V.
This issue only affects the use of the Expander without being in a eurorack system, but lots of folks are using the Plinky + Expander in a 3d printed case.
I understand D4 is to prevent USB power from colliding with euro power. Perhaps a jumper to select between VBUS and +5V for the expander power? Or perhaps provide both VBUS and +5V to the expander port (remove one of the GND or 3v3 pins) and have the expander select which one is used.
Using the plinky expander without a eurorack case does not work properly. The expander is connected to +5V, however schottky D4 prevents this +5V rail from powering the TPS61040 which in turn generates the +12V and -12V.
This issue only affects the use of the Expander without being in a eurorack system, but lots of folks are using the Plinky + Expander in a 3d printed case.
I understand D4 is to prevent USB power from colliding with euro power. Perhaps a jumper to select between VBUS and +5V for the expander power? Or perhaps provide both VBUS and +5V to the expander port (remove one of the GND or 3v3 pins) and have the expander select which one is used.