I2C總線接口和簡易IC卡讀寫器

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''定義LCD顯示屏接口''定義PPortc.

2、0為I2C總線的Scl''定義 PPortc.1為I2C總線的Dda''定義IC卡的寫地址指令字'定義IC卡的讀地址指令字'定義3個I/O 口為輸入開關(guān)接口''清LCD顯示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'顯示提示字符''檢測有無IC卡插入'無IC卡插入''有IC卡插入''檢測系統(tǒng)設(shè)置為寫卡方式?'寫卡方式，要求輸入密碼字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輸入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''的密碼字符，'長度為8個''同時在LCD上顯示密碼'將8個密碼字寫入IC卡中'寫入地址為1-8如果系統(tǒng)設(shè)置為修改系統(tǒng)密碼時'將密碼寫入 AVR的EEPROM中''寫入地址為1-8'讀IC卡剛寫入的密碼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''判別寫入密碼同用戶輸入的密碼'是否相同'相同，寫卡完成'不同，寫卡操作有誤或壞的IC卡'等待用戶抽出IC卡''系統(tǒng)為讀卡方式'讀IC卡上的密碼字8個'顯示在LCD上'讀系統(tǒng)密碼字8個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