STM8S103 using GPIOB4 as normal GPIO

[DSmit.5]

Hi all.

I tried to use GPIOB4 as output but failed.

But it works as I2C ​SCL so I guess the chip ok.

I cant find alternate function for it.

Someone please help me.​

[AA1]

How do you know it failed?

Post the code used to configure and write output value of GPIO.

[DSmit.5]

GPIO_DeInit(GPIOB):

GPIO_Init(GPIOB, GPIO_PIN_4, GPIO_MODE_OUT_PP_HIGH_SLOW);

GPIO_WriteHigh(GPIOB, GPIO_PIN_4);

It only can pull low not pull up.

​The same as GPIOB 5.

Might be both only OD not PP?​

[AA1]

The problem is what I expected. I2C pins are true open-drain pins, see datasheet. This means they can't drive level '1'. Also they don't have internal pull-up resistor. Use them to drive level '0' or try with an external pull-up resistor.

[DSmit.5]

Thank you.

STM8 much frustating than STM32 and other 8bit micros.

Dont know why ST made them complicated

[AA1]

I don't agree with you. You are complicating. You have to read datasheet and manual. Also the fact that can only drive level '0, usually is not a problem.

STM8 is a powerful 8bit MCU.

Do you already worked with any STM32 MCU?

And the RISC instruction set of CM0+ MCUs!

Also aligned access to memory!