Stm32f4disci power supply

[Blly]

I find a question. when I try to change the power for computer's USB interface to an extern 5V.it doesn't work.LD1 keep flashing.but when I use the computer's USB.it works well.what's wrong. I use it to produce a pwm.

[Tesla DeLorean]

Make sure to use current ST-LINK firmware, around V25 it held the device in reset on a charger type supply, and this is probably what shipped on DISC1

[Blly]

how to check my stlink version​?

[Tesla DeLorean]

Use the update tools? Tells you what's in there currently.

Updater built into ST-LINK Utilities and STM32 Cube Programmer app, stand-alone app has slightly newer version

https://www.st.com/en/development-tools/stsw-link007.html

[Blly]

how to provide the F4DISCI a properly extern​ power. I have applied such as 7805.Lm317.ams1117-5.lm2596s.but the pwm it produced is not what I want. only when I change the power from these modules to the computer's USB to the F4disci 's 5V pin. can it work well. what's wrong?

[Tesla DeLorean]

The 5V pins on the P2 header are the injection point for an external supply.

I've typically powered these boards via the Mini USB connector CN1

[Blly]

I don't mean the power supply interface, does F429disci have any requirements for power supply, such as low ripple coefficient, the voltage of ordinary voltage regulator module can't let him work normally, and the program will run away?

[Blly]

As long as the electricity from the computer USB interface can work, whether it is connected to Mini USB or plugged directly into 5V pin through DuPont line, but if the data line is pulled out and inserted elsewhere, such as 5V voltage regulator module or charging treasure, the program will run randomly.

[Tesla DeLorean]

Ok, so now STM32F429I-DISC1 not STM32F4-DISC1 (F407)

[Tesla DeLorean]

>> but if the data line is pulled out and inserted elsewhere, such as 5V voltage regulator module or charging treasure, the program will run randomly.

Data Line?

To some other board? You'd need to common the grounds.

Perhaps diagram, your description confused me.