I wanted to create a digital alarm clock about half the size of a small clock.
Components
Component List
| Number | Name | Type/Specification | Identifier | Number | Name | Type/Specification | Identifier |
| 01 | Resistors | 10K | R1 | 10 | T act switch | 6*6*5 | S1 |
| 02 | 10K | R2 | 11 | 6*6*5 | S2 | ||
| 03 | Capacitors | 30P | C2 | 12 | IC Socket | 20PIN | U1 |
| 04 | 30P | C3 | 13 | MCU | AT89C2051 | U1 | |
| 05 | 104P | C4 | 14 | Buzzer | 5V active | LS1 | |
| 06 | 10uF/25V | C1 | 15 | Digital tube | 4Bit red | DS1 | |
| 07 | Resistor Packs | 1K | PR1 | 16 | DC socket | 3.5mm | J1 |
| 08 | Crystal Oscillator | 12MHz | Y1 | 17 | PCB | 52*42mm | 1 |
| 09 | Transister | 8550 | Q1 | 18 | Power Line | USB to 3.5mm | 1 |
Schematic
Constructed Clock – just needs to be placed inside a small housing now. I’m thinking Altoids tin.
Features
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.