Bluepill Port B3 and Port B4

[corado]

How can I use GPIO B3 and B4?

I found this
GPIO_Alternate_Function_Enable(@_GPIO_MODULE_SWJ_JTAGDISABLE );

It works, with B3 but B4 ist invertet?


What's wrong?

[IvanJeremic]

Hi,

I have researched it for a bit and it seems that the PB4 pin won't work properly as a AFIO pin until first enable the clock on it.

Try using GPIO_Clk_Enable.

Regards,

Ivan.

[corado]

This works

Code: Select all

program STM32F103_Bluepill;
{ Declarations section }
{ Declarations section }
begin
 //SWJ_CFG0_bit:=0;
 //SWJ_CFG1_bit:=1;
 //SWJ_CFG2_bit:=0;
 GPIO_Digital_Output(@GPIOB_BASE, _GPIO_PINMASK_ALL); // Set PORTB as digital output
 GPIO_Alternate_Function_Enable(@_GPIO_MODULE_SWJ_JTAGDISABLE );
GPIOB_ODR:=0x0000;
While TRUE DO
 begin
 { Main program }
   GPIOB_ODR := not GPIOB_ODR; // Toggle PORTB
   delay_ms(1000);
 end;
end.