What is the pin mapping when we use an ADC in micro STM32F401?
Full datasheet for the entire STM32F40x family here. There are ways to configure ADC to automatically sweep across pins configured as ADC inputs and read the input on them. You can also manually do multiple single conversions, so check ADC1 reconfigure ADC for a different channel, check ADC2,... Read more in the supplied datasheet or learn how to use tools such as CUBE MX, which can do the configuration for you. You can also use already existing HAL libraries instead of writing your own functions to read ADC in various different modes. Combination of HAL and CUBE MX is what I would advise as you will only benefit from knowing how to work with those and they will make your life much simpler.