STM32F0 Discovery PF0 issue

[ei3hmb]

Posted on August 27, 2013 at 18:46

Hi there

According to 

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/user_manual/DM00050135.pdf

 PF0 is configured as GPIO.I didn't change any solder bridge settings but I cannot get access to PF0 as GPIO.PF1 works OK, PF0 doesn't.. the same configuration for both.I've tested it with three brand new boards.Any idea how to solve it?J. #rainbows-and-unicorns

[Tesla DeLorean]

Posted on August 27, 2013 at 20:30

I didn't change any solder bridge settings but I cannot get access to PF0 as GPIO.

Why not? You'll need to remove SB18 to stop getting an 8 MHz signal from the ST-LINK's F103, and you'll need to make SB17 to get it too the external pin frame.

[ei3hmb]

Posted on August 27, 2013 at 23:47That's from the manual:4.7.1 OSC clock supplyPF0 and PF1 can be used as GPIO or as HSE oscillator. By default these I/Os are configured as GPIO, so SB16 and SB17 are closed, SB18 is open and R22, R23, C13 and C14 are not populated.I undestand SB18 is open by default.Edit:I've checked it - all SB 16 to 18 were open.

[Tesla DeLorean]

Posted on August 28, 2013 at 02:39

That certainly deviates from the boards in my possession.

So, you'll probably want to stick a scope on the back of the board and see if you can get an 8 MHz clock. Then you'll want to look at how the pin is initialized. Make sure the GPIOF bank clock is enabled. Other STM32 parts needed some remapping of PDx pins, though there isn't any qualifier on the F0, but you do have to make sure that HSE is OFF/DISABLED.