BLE activity on LDO based schematic?

[earaid]

Hello, we have a custom board based on the CEAA WLCSP reference schematic with internal LDO setup. Our supply voltage is 1.8V (VCC_nRF). Unfortunately we don't see any BLE activity. When we probe the output of VDD_PA we don't see any activity.

I am testing with an unmodified version of HRM example code. When I test it with blinky example I see the GPIOs toggled as expected.

Appreciate any guidance.

[John]

Did you program the radio with the soft device stack before loading the HRM project? If you didn't the project won't work.

[earaid]

Yes I did load softdevice. The project worked fine on the evaluation board. We are thinking it has to do something with LDO vs DCDC. Our custom board is supposed to run at 1.8V. Is there a FW configuration I need to change to switch from DCDC to LDO?

[Nguyen Hoan Hoang]

The Blinky works means your power is ok. More likely your antenna does not work.

[John]

I've not had to deal with DCDC. I did see this thread that might have some useful information for you, I learned a bit reading it just now:

LDO vs DCDC

[earaid]

Thank you John, I did see this thread... I'm just stuck on how I can enable/disable the DCDC in firmware and softdevice. I cannot seem to find an API that does this.