Cannot access >=3,3V at GPIOA - STM32F411

[timbo2023]

Dear Ladies and Gentlemen,

for you it is your daily business - for me as customer a contemporary challenge:

Something went wrong with my pin-configuration.

I measure ~1,7 V as GPIO-output of Port A instead of wished >=3.3 V.

My power supply is a USB.

Could you give a sample pin configuration for (3.3 V output) of Port A in discussion?

As additional comment:

Round about 5 V are present at the 5 V-Pin(s).

Thank you in advance.

TIMBO

[SofLit]

Hello,

Which board you are using? a custom board?

You need to provide schematics as well. 

".. instead of wished >=3.3 V." -> that depends on your VDD.  What is your VDD level?

[Tesla DeLorean]

Reduce the load attached to the pin. Perhaps just remove and measure then.

[Peter BENSCH]

The TO talks about the Black Pill, probably this one.

[timbo2023]

It is a BlackPill (weact v. 3.0) -

To my purpose - I need the round about 5 V from 5 V-Pin at the outputs of PA0-PA3.

~ 3.3 V would be enough, but I measure ~1.7 V at the moment...

It seems to be a configuration thought...

[SofLit]

BlackPill/BluePill are not boards of ST and unfortunately some of them have fake STM32 on them!

Meanwhile, even with a genuine STM32 you can't reach 5V. The maximum you can reach is 3.6V which is the maximum of VDD.

[Andrew Neil]

---

@timbo2023 wrote:

I need the round about 5 V from 5 V-Pin at the outputs of PA0-PA3.

---

The STM32 - like most such microcontrollers - is a 3.3V device.

It is not a 5V device.

Therefore you are never going to get a 5V output directly from its output pins.

Are you, perhaps, confused by the term "5V tolerant"? That refers to inputs which can tolerate 5V - it has nothing to do with outputs!

[timbo2023]

Ohhwee, that we must consider & check, of course.

On the 5 V pin were 4. ..V with USB given.

Is it possible to reach this voltage direct on another pin of port A?

But:

~3.6 V would be enough - VDD - of course - How looks the configuration of the pin0-3 of port A regarding it?

[AScha.3]

You are on a 3.3V system. 

If you want 5V signal, no problem, use a chip for level shifting 3 -> 5 V . (I do same, if 5v signals needed.)

You can take any .. ie : 74HCT125 (with enable) , or ->

https://www.mouser.de/c/semiconductors/logic-ics/buffers-line-drivers/?logic%20family=74HCT&polarity=Non-Inverting

[timbo2023]

Thank you, Mr. NEIL - ok, that i understood with support of your answer.

But back to VDD with its reachable value - I measure after a pin configuration ~1.7 V - how should be the configuration to reach the "full" 3.6 V on the pins of port A.

Could you give a sample?