2023-05-24 11:50 PM - edited 2023-11-20 04:39 AM
Hello all, I don't know why but my MCU STM32F303CCT6 don't work with external crystal, below schematics:
The used crystal is ABM3B-8.000MHZ-10-1-U-T with load capacitors 10pF. Later I find in STM Datasheet that I should use resistor on OSC32_OUT pin. Is the resistor necessary to work? Or maybe i use wrong crystal? Thanks a lot for help to solve my problem :)
Solved! Go to Solution.
2023-05-25 07:12 AM
no - you just connected to the wrong pins !
crystal for cpu clock is on PD0+1 , but you connected to 32kHz clk /crystal at PC14+15 !!!!
so connect it to right pins or use internal clk...
2023-05-25 01:38 AM
2023-05-25 06:09 AM - edited 2023-11-20 04:39 AM
I saw this document but unfortunately after ordering the PCB. But it is puzzling to me that, for example, bluepill board designs have different solutions, one with a 1M resistor and the other without resistors. In the second case, this Bluepill board works, but unfortunately not in my case.
WeAct bluepill crystal schematics:
and noname bluepill board:
My PCB crystal schematics is exactly as in Weact bluepill?
Could I have damaged the crystal too high temp, hot air soldering?
2023-05-25 07:12 AM
no - you just connected to the wrong pins !
crystal for cpu clock is on PD0+1 , but you connected to 32kHz clk /crystal at PC14+15 !!!!
so connect it to right pins or use internal clk...
2023-05-25 07:15 AM
> bluepill board designs
They contain a STM32F103 (and these days, a random choice of some of the dozen clones), that's a different mcu with different oscillator design, and potentially uses a different crystal than you. So, you are comparing apples to a selection of various fruits and often also vegetables.
Read AN2867, mainly chapter 7, and also the parts which deal with the load capacitors calculation.
JW
2023-05-25 09:57 AM
Thanks a lot! You have right
2023-05-25 01:53 PM
Nice catch! :)
JW