Efficiently regulate from around 5V to 3.3V (for MCU) and 4.0V for SIM800L GPRS

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1

Hello Arduino-fellows,

I think I have a tricky question for you: I would like to power an MCU with a voltage of 3.3V and a SIM800L module with a voltage of 4.0V. At the moment, I use a voltage regulator from polulu to convert the power supply voltage (4xAA NiMH) to 3.3V and just power the SIM800L over 3xAA NiMH.

Preferably, I would like to keep the 3.3V for the MCU also for the Tx,Rx ports and the attached sensors.

I have thought about using Low dropout voltage regulators (LDO), standard diodes, zener diodes but I'm not sure what's the best approach here.

Thank you!

2

Why those two voltages? How will you handle the logic level interface problem?

I can't imagine it is worth the effort, since neither requires a regulated supply voltage.

3

use lm 2596 buck module to power the sim800l module . and use pro mini or an esp32 as both are 3.3v MCU. then you can directly connect rx tx with sim module.