BC127 Switchable Power Output

Is there a way to use the BC127 to switch a micro controller on/off at the same time the BC127 is put into sleep mode?

I thought I had read in some of the documentation that you could use the supply output pin in this way but it seems like this pin only serves as a 3.3V regulator from whatever is on VCHG.


So what do you want to do, toggle an IO or something as soon as the BC127 goes to sleep? Not sure that is possible.



Could I use the GPIO4 to go high if connected/low if not connected to drive a transistor or mosfet as a switch?
Or could I use the class1 behavior to do something similar?



still not clear on what you want to do? Class 1 of what?

If the unit enters sleep mode the UART would go inactive and drop CTS, this would be the best thing to trigger off.



I want to use the BC127 to turn on an auxiliary power source, Id like to power a microcontroller that needs 50mA or less at 3-5V.

As I see it this can happen in a couple ways.

  1. The BC127 has some sort of switchable power output - I was hoping this was how the 3V3_USB pin worked but it seems like it is only powered when VCHG is powered - this option does not seem like it will work.
  2. A GPIO pin can be written high via a command or programmed to go high on startup/event of the BC127 - I could use this control signal and a transistor like a relay to switch on the microcontroller

The datasheet talks about external amplifier support and says PIO3 should go High when an audio link is established but also says this is only on non MFI builds and I have an MFI build.

Alternately, the Melody 6 website talks about the configurable parameter “class_1” that can be used to drive PIOs 0 and 1 to power an external amplifier.

The same section talks about configuring GPIO4 to go high when audio is streaming by setting GPIO_Config=OFF 080 254.

No configuration I have tried has gotten any GPIO pin to go high under any condition.

Thanks, Calvin