I2C总线接口和简易IC卡读写器

1、$regfile = "M16def.dat"$crystal = 11059200$baud = 9600Dim I As Byte , Temp As ByteDim Data1(8) As Byte , Data2(8) As ByteDim Card_ok As BitConfig Lcdpin = Pin , Db4 = Portc.4 , Db5 = Portc.5 , Db6 = Portc.6 , Db7 = Portc.7 , E = Portd.5 , Rs = Portd.3''定义LCD显示屏接口''定义PPortc.

2、0为I2C总线的Scl''定义 PPortc.1为I2C总线的Dda''定义IC卡的写地址指令字'定义IC卡的读地址指令字'定义3个I/O 口为输入开关接口''清LCD显示Config Lcd = 16 * 4Config Scl = Portc.0Config Sda = Portc.1Con st Adresw = &HA0Const Adresr = &HA1Config Pin c.0 = In put , Pinc.1 = In put , Pinc.2 = In putPortc.0 = 1 : Por

3、tc.1 = 1 : Portc.2 = 1Cursor Off Nobli nkDoCls'显示提示字符''检测有无IC卡插入'无IC卡插入''有IC卡插入''检测系统设置为写卡方式?'写卡方式，要求输入密码字Locate 1 , 1 : Lcd "Demo for IC_Card"If Pi nc.2 = 1 The nLocate 2,1 : Lcd "No IC_Card "Wait 1ElseIf Pi nc.0 = 0 The nClsLocate 1 , 1 : Lcd

4、 "Enter Password:"I = 1Locate 2,1Do由RS-232 口接收PC输入Temp = In key()If Temp <> 0 The nData1(i) = Temp : I = I + 1 Led Chr(temp)Print Chr(temp);End IfLoop Un til I > 8PrintFor I = 1 To 8I2cstartI2cwbyte AdreswI2cwbyte II2cwbyte Data1(i)I2cstopWaitms 10NextIf Pi nc.1 = 0 The nFor I = 1

5、 To 8Writeeeprom Data1(i) , I NextEnd IfFor I = 1 To 8I2cstartI2cwbyte AdreswI2cwbyte II2cstartI2cwbyte AdresrI2crbyte Data2(i) , Nack I2cstopNext''的密码字符，'长度为8个''同时在LCD上显示密码'将8个密码字写入IC卡中'写入地址为1-8如果系统设置为修改系统密码时'将密码写入 AVR的EEPROM中''写入地址为1-8'读IC卡刚写入的密码Card_ok

6、= 0For I = 1 To 8If Data1(i) <> Data2(i) ThenCard_ok = 1Exit ForEnd IfNextLocate 2 , 1If Card_ok = 0 The nLcd "Write Card ok!"ElseLed "No or Bad Card!?"End IfDoLoop Un til Pi nc.2 = 1ElseCls : Locate 1 , 1For I = 1 To 8I2cstartI2cwbyte AdreswI2cwbyte II2cstartI2cwbyte Adres

7、rI2crbyte Data1(i) , NackI2cstopLcd Chr(data1(i)NextFor I = 1 To 8Readeeprom Data2(i) , I''判别写入密码同用户输入的密码'是否相同'相同，写卡完成'不同，写卡操作有误或坏的IC卡'等待用户抽出IC卡''系统为读卡方式'读IC卡上的密码字8个'显示在LCD上'读系统密码字8个NextCard_ok = 0For I = 1 To 8If Data1(i) <> Data2(i) ThenCard_ok = 1Exit ForEnd IfNextLocate 2,1If Card_ok = 1 The nLcd "Password not ok!"ElseLed "Password Ok!"End IfDoLoop U