STM32 Internally Pulled up pin

[Anurag Mahajan]

Posted on April 30, 2018 at 12:57

I am trying to digitally turn LED HIGH and LOW using STM32F103C8T6  maple mini board using pins A11, A12, B4 and A15 pin, But it seems that those pins are internally pulled up as soon as I power it on stm32 boards this pins get +3.3, 1.9 and 0.5 volt, If this pins are internally pulled up, How do I make them work? and If i try to digitally turn those pins HIGH and LOW using programming, this does not bring any effect on LED's. I would like to know, How do i control LED's using these pins,

Regards

Anurag Mahajan

[waclawek.jan]

Posted on May 01, 2018 at 09:59

PA11 and PA12 are USB DM and USB DP. Don't you have USB connected?

Similarly, check what's connected to the remaining pins on the board. They may be used by the debugging header (JTAG or SWD), if there is one.

JW