ESP32 #61: Level Shifting - MOSFET Level Shifter

Using the #ESP32 and using sensors with different voltage levels and using a level shifter.
Development Environment
ubuntu 17.10 64 Bit (www.ubuntu.com/) (for videocapture and -editing switch back from wayland to unity :( )
Eclipse Oxygen (www.eclipse.org/)
esp-idf commit 2c95a77cf93781f296883d5dbafcdc18e4389656 Tue Oct 24 10:02:51 2017 +0800 (github.com/esp...)
xtensa-esp32-elf-gcc (crosstool-NG crosstool-ng-1.22.0-61-gab8375a) 5.2.0 (dl.espressif.c...)
Arduino 1.8.4 (www.arduino.cc/)
arduino-esp32 commit 07685903321a1968174f1a5027be88adb77b8817 Wed Oct 25 12:11:01 2017 +0200 (github.com/esp...)
With CC or Public domain Pictures from pixabay
pixabay.com/p-...
see also other videos about level shifting:
• Short Circuits Logic L...
• Level Shifting Tutoria...

[@MrDehicka]

Simplest way for 3V5V is just use current limiting resistors. Almost any modern MCs have input clamping diodes that can do up to several milliamps. With 10k resistor and 2V overhead it will be less than 0.2mA clamping current, which is perfectly fine.

[@t1d100]

I have been struggling to understand the operation of the bidirectional MOSFET solution. Your narrative corrected my understanding. Thank you.

[@geoptus]

Thanks, very handy use of a mosfet to know.

[@IsaacWRTorres]

So, if i want to make a 3.3v to 5v. The 3.3v gpio has to ve conected to the resistor-mosfet at the same time as the ground?

[@emmetray9703]

why we need 10K resistor connected to the 3.3v ? what if we remove it at all?

[@FlyingCircles]

It's a conductive path to the source. If you remove it, there will be no path to control the high/low of the opposite logic level. If you short it, you will have a null-impedance path to ground upon conduction which will short the FET

[@audiokees4045]

I try to get a flying cap three level switcher with lmg1205 chips to get the high floating working with level shifting psm inputs, no succes until now. Someone a hint?

[@ElecDashTronDotOrg]

I use the 74LS245 its capable of HIGH speed 3.3v to 5V, but not backwards

[@pcbreflux]

Thanks. Have you maybe also the test 74HC245 CMOS level ? Any timing difference?

[@ElecDashTronDotOrg]

pcbreflux have not tried the CMOS one, i mainly use these for level shifting to Addressable LED pixels