Hi.
I am developing a custom board using nRF52840 inside a Moko MK08A and an accelerometer LIS2DH.
My circuit has a 3V3 voltage regulator just for the LIS. The microcontroller is powered directly by a 3V6 battery.
I was performing some tests with diffent voltages and realized that when I power the circuit with a voltage lower than 3V3 the output voltage of the voltage regulator "follows" the input voltage and both accelerometer and microcontroller works fine. But when I raise the voltage above 3V3, the nRF52840 and the LIS start working with diffent voltages (3V3 from the voltage regulator to the LIS and the source voltage (more than 3V3) to the nRF).
In this moment the LIS stop working (or the SPI communication).
My issue is, do the SPI communication between the LIS and the nRF52840 have to be in the same potential for they to work? Or what coud be the problem?
Thanks.
