all help appreciated..

[Gravesen16]

Hi,

I have recently been asked to describe the role of the parts in the following circuit

https://www.maplin.co.uk/Media/PDFs/N21FL.pdf

If anyone can give me any advice on this, please do, it will be highly appreciated!
I am trying to find out why the certain values are picked and what roles the values of capacitors and resistors play in this circuit.

Thankyou in advance!

Bruce.

 

[RCinFLA]

10k's are just pull down resistors to assure default logical zero on input ports of uP. All other resistors are for LED current settings. IC2 is 5v regulator, look up 7805 for rest of 5v regulator circuit details. Q1 is 32 kHz crystal for uP clock generation. C1,C2 set loading capacitance on crystal for precise frequency of crystal.