Interfacing Max232 with stm32

[Nidhal Abidi]

Posted on May 03, 2018 at 14:00

I'm working with stm32vldiscovery and I'm going to use max232 for USART. 

I'm using usart1 (pA9 and pA10 as TX and RX).

The question is witch is the best way to make it wortk correctly and safetly specially with the RX pin in the STM32 cause

max232 has 5V as output then  the stm32 works with 3.3V. 

Should I use power divider or npn transistor with high frequency or .... ???

[waclawek.jan]

Posted on May 03, 2018 at 22:24

Use MAX3232 or similar (e.g. ST's

http://www.st.com/en/interfaces-and-transceivers/st3232eb.html

) transceiver, which is designed to work with 3V power supply. Except for the supply voltage and related logic levels on the 'logic' side, they are fully pin and functional compatible with MAX232.

JW

[Nidhal Abidi]

Posted on May 03, 2018 at 23:38

For some reasons I just could work with MAX232. Neither 3232 or 3223 ...

I guess voltage divider works but I'm searching if there's a better way.