4×4键盘及8位数码管显示构成的电子密码锁是通过键盘输入密码，然后通过数码管显示!-4 × 4 keyboard and 8-bit digital tube display constituted by an electronic lock keypad to enter a password, and then LED display!

MC14489驱动五位共阴极数码管，应用DSPIC33F来驱动MC14489，从而点亮数码管，显示12345-MC14489 five common cathode LED driver application DSPIC33F to drive the MC14489, lighted digital display 12345

AD采样，数字测频器，直流稳压电源，液晶显示和键盘数码管显示-AD sampling, digital frequency measurement, DC power supply, LCD display and keypad LED display