AnsweredAssumed Answered

PULL UP DOESNT WORK ON stm32F100RB

Question asked by TARHAN SAMAH on Sep 19, 2017
Latest reply on Oct 12, 2017 by TARHAN SAMAH

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
K5_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;

HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

 

, 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 

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