DFR0478 use external 32.768kHz crystal and it cannot oscillate
Rancho.Liu 2023-10-31 13:51:35 220 Views0 Replies Hi DFROBOT Tech team
Our customer purchased that DFROBOT MPN#DFR0478 and found this board cannot oscillate when use external 32.768kHz crystal, detail refer to below description，can you help and advise?
In our application, we use external 32.768kHz crystal to do the Real time clock. Now it cannot oscillate, and our system cannot be programmed and start up.
No crystal oscillation is found on the two pins. See the schematics attached.
After changing of the two loading caps (C32,33) on the oscillator, it works again.
The on-board crystal 32.768kHz cannot oscillate and create fatal order in our application. We need to change the two capacitors below to 12pF to recover. We have done this fix on all the 5 units purchased last time.
