external crystal

[psj]

Hello is a starter developer I used the nrf51822 chip on the pcb board and downloaded the example code but it did not work. When I checked the 16mhz external crystal on the pcb board, the clock was not being generated. I knew there was no need to write code to use external crystals. Do you have to set an external clock with the code? Please advise.

[suvarna_kadam]

I am also facing the same problem. I have custom board of nrf51822 and 32kb external crystal is used. I am using uart example without softdevice from sdk 11. Board is getting detected in nrf go studio and also get programmed but unable to see output of it and also having same problem with ble uart program with softdevice 130. Do I have to do some changes in program related to a crystal frequency or any other setting is required?

[Jørn]

You say you have a 32kb crystal, do you mean 32MHz? If you take a look at page 51 of the nRF51 reference manual, it states " If a 32 MHz crystal is used the XTALFREQ register must be configured accordingly.". You can find information on the register in table 72, on page 55 of the same document. You will find that the default value of the register is 0xFF, which corresponds to a 16MHz crystal being used. You will need to change the value there to 0x00 to correctly use a 32MHz crystal.

[Jørn]

It has also been pointed out to me you can adjust the reset value of the XTALFREQ register by altering the corresponding register entry in the UICR. That way the XTALFREQ register would be set correctly upon reset.