附录三 原理图

D1D2D3D4D5D6D7D8R23220R24220R25220R26220R27220R28220R29220R30220LEDLEDLEDR1R2R3R4R5R6R7R89012Q19012Q29012Q39012Q4LEDLEDLEDLEDLED1234567891011121314151617181920U1P1.0P1.1P1.2P1.3P1.4P1.5P1.6P1.7RESETRXDTXDINT0INT1T0T1WRRDXTAL2XTAL1GND8751VCCP0.0P0.1P0.2P0.3P0.4P0.5P0.6P0.7EA/VPALE/PPSENP2.7P2.6P2.5P2.4P2.3P2.2P2.1P2.040393837363534333231302928272625242322214.7kJ2四位数码管R9R10R11R12R13R14R15R16100100100100100100100100C122ufS9J321VCCC230pfC330pfY16MHZR181KS1S2S3S4S5S6S7S8R17220abcdefdgpGNDCON2J1123CON44R22R21R20R194.7K4.7K4.7K4.7K1234 附录四 PCB图