Based on HT82K629A numeric keypad

    HT82K629A is an excellent USB keyboard dedicated chip with simple application and few peripheral circuits. It can be used directly connected to the computer without downloading drivers and code control. Simply the best choice for DIY keyboard! Lichuang Mall sells dual in-line and SMD packaging types to meet all your needs! ! ! Attached is the mall purchase link: https://so.szlcsc.com/global.html?k=HT82K629A

• Physical map

• Application diagram

• Welding diagram

• Empty board

• Button connection diagram

• Debugging failure:

1. The diode is soldered backwards. Please pay attention to the direction of the diode corresponding to the PCB diagram.

2. There is a key on the shaft that does not work, and it does not display when pressed multiple times. After removing the button, the short circuit shows normal, but the button is faulty. Replace the button to solve the problem.

• project progress:

1. 2020-03-20 Modify the crystal oscillator circuit in the schematic diagram
2. The test was completed at 8pm on 2020-03-23.
3. The schematic diagram has been modified, waiting for the PCB update, and the solution has been verified.
4. PCB wiring V1.2 version completed late on 2020-03-24