Monday Kids Accurate C51 Electronic Clock 4 Bits Clock Kit DIY Electronic DIY Kit LED Display Electronic Modules DIY Electronic Modules

AT89C2051-based of four electronic clock kit

Kit Model: YSZ-4
Supply voltage: 3V-6V
PCB Size: 52mm * wide 42mm

Function :

1. Seconds correction (for precise School)
2. Switch to every minute independent display interface
3. whole point of time (8-20 o'clock chime can be turned off)
4. Two alarm settings (you can turn off the alarm function)

Kit Features:

A. 0.56 inch special red digital clock for display;
B. Import AT89C2051 for master chip;
C.1.2mm thick PCB made from military grade FR-4 board;
D. accurate travel time, travel time error range error -1 to +1 seconds every 24 hours.

This kit contains a USB to 3.5mm power cord, plug in the USB charger can be used.

1. Introduction

YSZ-4 four electronic clock, it takes AT89C2051 as its core, a total of 16 electronic components to come true the two channels of the alarm clock, (8:00-20:00) on time alarm ,accurate adjustment , and other functions.

2. Parameter

3. Principle

The whole system by MCU minimum system, key input circuit, display circuit, buzzer circuit and power supply parts.

1>. MCU minimum system: including the U1 (AT89C2051), C1, R1 for power on reset circuit .Clock circuit is composed of C2， C3 and Y1.

2>. The pressed key input circuit：composed of S1, S2, short press the button once a loud buzzer rang, long press the button once two loud buzzer rang.

3>. The display circuit：4bits common cathode and on PR1 Resisters Packs .

4>. Buzzer circuit：composed of Q1, R2 and LS1, short press the button once a loud buzzer rang, long press the button once two loud buzzer rang.

5>. J1 is 5v power supply input terminal, C4 filtering.

4. Operation instruction

It will display 12:59 when Power-on，while is normal interface("hours:minutes"). The both channels of alarm clock are opened.At the same time,the first alarm clock has been set at 13:01.the second alarm clock has been set at 13:02.

After power on ,short press S2.The display of digital tube will switch between "hours:minutes" and "minutes:seconds";Long press S1 to enter the system Settings menu. there are A, B, C, D, E, F, G, H, I submenu. Short press S1 sub-menu plus increase by degrees.finally back to the normal interface

A Sub menu : Correction for hours

Display data will add 1 after press S2.after adjusted the A Submenu,then short press S2 to save the adjusted results and quit A submenu,enter B sbumenu

B Sub menu : Correction for minutes

Display data will add 1 after press S2.after adjusted the B Submenu,then short press S2 to save the adjusted results and quit B submenu,enter C sbumenu

C Sub menu:on time alarm switch

The default state is ON (on-time-alarm is open from 8:00 to 20:00)

It will switch between ON and OFF(on-time-alarm is closed) when press S2. Short press S2 to save the adjusted results and quit C submenu,enterD sbumenu

D Sub menu:The first alarm-clock switch

The default state is ON (the first alarm-clock is opened)

It will switch between ON and OFF(first-alarm-clock is closed) when press S2.

If set to ON, short press S1 to save and quit,then enter E submenu;

If set to OFF, short press S1 to save and quit ,then enter G submenu;

E Sub menu:The first alarm clock set for hours

Display data will add 1 after press S2.after adjusted the E Submenu,then short press S2 to save the adjusted results and quit E submenu,enter F sbumenu

F Sub menu:The first alarm clock set for minutes

Display data will add 1 after press S2.after adjusted the F Submenu,then short press S2 to save the adjusted results and quit F submenu,enter G sbumenu

G Sub menu:The Second alarm-clock switch

The default state is ON (the second alarm-clock is opened)

It will switch between ON and OFF(second-alarm-clock is closed) when press S2.

If set to ON, short press S1 to save and quit ，then enter H submenu;

If set to OFF, short press S1 to save and quit ，then enter normal interface;

H Sub menu:The second alarm clock set for hours

Display data will add 1 after press S2.after adjusted the F Submenu,then short press S2 to save the adjusted results and quit H submenu,enter I sbumenu

I Sub menu:The second alarm clock set for hours

Display data will add 1 after press S2.after adjusted the I Submenu,then short press S2 to save the adjusted results and quit H submenu, then enter normal interface.

Second correction:

Short press S2 in the normal interface,then enter "minutes : seconds" interface .Long press S2,make the second zero.Then short press S2 twice enter normal interface

5. Schematic

Note: there is direction for PR1 Resisters Packs , there is one side of the word in the direction of the MCU.Pay an attention!!!

6. Component listing

NOTE :Users can complete the installation by PCB silk screen and component listing