How to connect a battery to a STM32F429ZI DISCO board ?

[ABIZO.1]

Hello,

I have a STM32F429ZI DISCO board and I want to connect it to an external supply but I don't know wich pins I have to connect. Vdd on 3.3V ? or 5V pin ? or 3V pin and 5V pin ? or all of them ?

Any one can help me to connect my board ?

Thank you !

[Peter BENSCH]

You should only feed in either 5V or 3V. But no matter if 3V or 5V: a battery is surely not a really good idea, because in both cases the embedded ST-LINK/V2 is also supplied, so it consumes additional energy.

Now you could get the idea to connect the battery to VDD (P1.22) and remove JP3, so that the STM32F429 is disconnected from the 3V signal. However, this also disconnects the DRAM U6, so that no frame buffer can be used there anymore, also MicroUSB is disconnected, which is controlled via U8.

Please keep in mind the DISCOVERY are not universal maker boards, but intended for evaluation: the JP3 is actually primarily intended for measuring the current consumption of the STM32F429.

Regards

/Peter

[ABIZO.1]

I don't really understand,

I connect my 3.3V supply to Vdd pin, then I disconnect the JP3. But when I do that, my LCD screen is disconnect...

And for my application, I have to use the 3V pin. How can I do this ?

[Peter BENSCH]

As mentioned before: via VDD you supply only the STM32F429.

If you want to use the rest of the functions (LCD, etc), you can only supply via 3V or 5V.

Regards

/Peter

[ABIZO.1]

Ok thank you for your answer I understand now