Tagged Questions

4
votes
4answers
323 views

Why aren't 1Hz crystals used to measure seconds?

According to Wikipedia: Many clocks use a 32.768KHz crystal. Is this because the crystal is smaller than a 1Hz crystal? If 1.0 Hz == 1.0 second. Then, why the need for the division?
2
votes
4answers
86 views

What kind of oscillator should I use for a binary clock?

I've seen that a lot of clocks use a 32.768KHz crystal. I'm curious why that is exactly. I am working on a binary clock project with some 4520 ICs. I have some 555 timers too, but I want to use a ...
6
votes
3answers
277 views

Crystal circuit works in breadboard but not in perfboard

I'm a beginner and I'm trying to build a digital clock. My clock generator looks like this: It works perfectly on the breadboard, where I can see the LED blinking at 2 Hz. However, when I try to ...
1
vote
1answer
85 views

Choosing Resonator for AtMega328P design

The ATMega328P datasheet specifies a load capacitance for a resonator from 12-22pF but the only 2 Resonators that will fit in my design (from Digikey) have 10pF and 33pF internal capacitors. Which one ...
2
votes
1answer
606 views

Setting up an external clock source on an ATmega8

I am attempting to set up V-USB on my ATmega8-16PU (datasheet), and could use some help hooking up an external crystal clock source to it. I have tried to understand the datasheet to the best of my ...
-2
votes
4answers
593 views

Generation of clock signals

Inside a computer, a crystal oscillator sends signals to a microcontroller or microprocessors. I want to know if the crystal oscillator is increasing the frequency or generating pulses. My questions ...
1
vote
2answers
768 views

Digital Clock Circuit

I am making a solid wood clock using minimal components. So far, I thought of using 21 LEDs to make 7 segment displays (3 LEDs for each segment (overall 63 LEDs for the displays)), 6 LEDs for the 1 in ...
5
votes
1answer
806 views

Real-time clock and Crystal precision

I want to use a crystal as the base clock for a watch. Most reference designs I could find use a 32.768 kHz crystal at 20 ppm (parts per million) precision. According to my calculations, this leads to ...