Hello , i try to make a program scanning a keypad 4*5 with stm32F100RB so i have to use 5 inputs as pull up (using internal resistor of the mcu ),
after initiating with cube i got this
/*Configure GPIO pins : K1_IN_Pin K2_IN_Pin K3_IN_Pin K4_IN_Pin
GPIO_InitStruct.Pin = K1_IN_Pin|K2_IN_Pin|K3_IN_Pin|K4_IN_Pin|K5_IN_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
GPIO_InitStruct.Pull = GPIO_PULLUP;
, after compiling and programming and i didnt connect any resistors of course ,, at the start up i mean before any application my pins gives 0v ???? is it normal it should give 5v (or 3,3v) ...why is that ??
what should i add more to have the pull up .
for information i use these pins PB1 B2 B10 B11 B12 ..
THANKS PLZ URGENT ADVİCE ME WİLL BE APPRECİATED
Doumandji Samah Ayluçtarhan
R &D ENGİNEER at Argebilisim Turkey