Can I use my unused SPI pin (MOSI) PA7 As analog input in STM32F405?

[Reema O]

Posted on March 30, 2018 at 01:41

I am on using selected pins in SPI1 on Port A in STM32F405. Can I used my  unused MOSI pin as Analog input channel?

[waclawek.jan]

Posted on March 30, 2018 at 12:05

Yes.

JW

[Reema O]

Posted on March 30, 2018 at 17:23

Thank you for confirming. I believe same is true for PC15 /OSC32_O and 

PC14 /OSC32_I.

[waclawek.jan]

Posted on March 30, 2018 at 21:16

If you don't use LSE (i.e. don't switch it on in RCC), then these two pins are free to be configured by GPIO module.

You can set them as Analog (thus switching off the digital input Schmitt trigger), but there is no connectivity from PC14/PC15 to the ADC.

If you use them as GPIO outputs, note, that they have limited drive capability - read the remark under the pins table in datasheet.

JW