2020-01-24 09:47 PM
2020-01-25 12:35 AM
The external crystal is needed only for USB, or when some timing task requires better accuracy than HSI.
E.g. as an asynchronous UART requires 5% accuracy, it might not work reliably in extreme temperatures.
2020-01-24 11:19 PM
you can use internal clock
2020-01-25 12:04 AM
Dear Dbarasiya
do you mean I don't not need to add a 8MHz crystal oscillator in my PCB?
2020-01-25 12:14 AM
Check the electrical characteristics chapter in the reference manual, both for ADC and the HSI internal oscillator. If they are adequate for your need, then no external components are needed apart from the decoupling capacitors.
Also read AN2834 How to get the best ADC accuracy in STM32 microcontrollers
2020-01-25 12:22 AM
hope you understand what i means as @berendi has explained
2020-01-25 12:22 AM
Best of luck
2020-01-25 12:35 AM
The external crystal is needed only for USB, or when some timing task requires better accuracy than HSI.
E.g. as an asynchronous UART requires 5% accuracy, it might not work reliably in extreme temperatures.
2020-01-25 01:26 AM
Dear berendi
your reply is very helping! thanks :folded_hands:
2020-01-25 03:35 AM
The internal frequency HSI has some tolerances across chips, temperature etc... you will get a min-max range from this.
Now check if all your peripherals are ok with this.
Using USB? Need probably HSE
Using high speed UART? Need probably HSE
Using RTC? Need probably 32.768kHz HSI
2020-01-25 04:42 AM
Dear .
so if I need UART, then I should add a 8MHz crystal oscillator, right?