COnnecting PPK to NRF52 Dk with external sensor connected to the VDD

[campestring]

Hello everyone, 

I would like to use the PPK with a NRF52 Dk, but I have external sensors connected to the VDD and 5V, so when I will plug the ppk I will have to disconnect the sensor alimentation. So I would like to know If it's possible to use the ppk with external sensor connect to the Dk to be included in the consumption of the board. 

Thank you, Have a good day ! 

Best regards,

Arnaud

[Stian Røed Hafskjold]

Hi, You can try to connect the external sensors to the same power domain as the nRF52 chip is powered from (VDD_nRF). On P20 you can see that there are two pins called VDD_nRF. They are not available when you plug the PPK on top, but they're the same pins as on the nRF current measurement header. So you can try to power the external sensors from the current measurement header on the nRF side (pin closes to the debug out port).

[campestring]

I don't have enough tension on this pin to supply my sensor, I have 2V... External DUT on PPK could be used for this ? I know this is for external system but when it's in Dk mode ? 

[Stian Røed Hafskjold]

You can choose either external DUT or DK mode. Not both.

The PPK only outputs one voltage. And the maximum voltage is 3.6V

So you are powering the nRF52 DK with 2V from the PPK regulator? And the sensors are using 5V? 5V is too much for the nRF chip.

Usually you can't have different voltages on the nRF chip and the things connected to it, since the GPIO voltages have to match. Unless you are using a level converter.

[campestring]

the sensors are using 3.3V, but I Don't know where to find the 3.3V ? on the NRF current mesurement pin I only have 2V maximum... 

[Stian Røed Hafskjold]

You can use the onboard regulator on the PPK. Set the Power select switch to "Reg", and then use the PPK software to adjust the output voltage to 3.3V.