【導(dǎo)讀】1.1設(shè)計(jì)要求···········································2. 1.2系統(tǒng)方案選擇和論證·································2. 1.3電路最終方案確定···································4. 2.2系統(tǒng)硬件各模塊作用·································5. 2.單片機(jī)核心控制模塊···························5. 2.實(shí)時(shí)時(shí)鐘電路模塊·····························6. 2.液晶顯示電路模塊·····························17. 2.USB和外部電源供電模塊····················