Does nrf51822 have a clock?

[benevbright]

Hi,

I wonder if nrf51822 has a clock inside it. It doesn't need to be real clock

but It's important to me. I store datas on flash and send it to the phone when it's ready to send.

But there is no guarantee that device is alive. so I store its time together when they are stored. so that I could send it with time difference from now.

but I have to need a clock for the case that battery is gone.

So is there a clock like?

[benevbright]

@Michael. Thanks for your help. but as you said little, there is no guarantee that device sends something to phone before it turns off. The phone could be at the outside or could be not connected with device. So I need to make device to figure out itself.

[benevbright]

So, the result is that I need to add some external stuff? Thanks.

[Michael Dietz]

I think so. Sounds like you'll need to do what Wojtek said.

[BLEdude]

Maybe instead of sending its last time to the phone, the device can save the time to its persistent storage. And then when it reconnects to the central, it can send the time it saved, and the central can figure out the difference in time?

[benevbright]

@BLEdude What if device turns off or battery is gone? That's why I asked you guys. It has to have clock something. I thought it has it of course.