Crystal Tester With BC547

Here is a simple circuit that can be used to test a crystal before using it in a circuit. The circuit is built around two BC547 transistors (T1 and T2) and a few discrete components. 

 The oscillator circuit formed by transistor T1, resistors R1 and R2, and capacitors C1 and C2 oscillates if a good crystal is connected to the test points marked as CUT (crystal under test). The output from the oscillator is rectified by diode D1 and filtered by capacitor C3. The positive voltage appearing across the capacitor is fed to the base of transistor T2, causing it to conduct.

Testing of a crystal is simple: Insert the crystal at CUT points shown in the circuit diagram and press test switch S1. If LED1 glows, your crystal is good and you can use it in a circuit.

The circuit is powered by a standard 9V battery. Push-to-on switch S1 is included to prolong the battery life but it’s not needed if you use a socket for the crystal under test.

Assemble the circuit on a general-purpose PCB and enclose in a suitable small cabinet. Fix the two-pin connector, LED1 and test switch on top of the cabinet. Fix the 9V battery inside the cabinet.

Note. You can use 2N3563 transistors instead of BC547. 

Digital Calender Using 8051

This Digital Calendar using Microcontroller is an advanced digital calendar, which displays the Date, Day, Month over the LED display. It has an 8 bit Microcontroller which runs on the Program embedded on its ROM. Separate LED's are provided for the date, day, and month. The system has an battery backup so that it can run over all the time even during the power failure.
Totally there are 31 LED's for indicating the date and 12 LED's for indicating the Month and 7 LED's to indicate the day. All the above systems are controlled by the Microcontroller.

Code:

DAY_RST EQU P3.2 DAY_CLK EQU P3.3 MON_RST EQU P3.4 MON_CLK EQU P3.5 UP EQU P3.7 ;black DOWN EQU P1.0 ;white SELECT EQU P1.1 ;red DATE_RST EQU P1.2 DATE_CLK EQU P1.3 DATE2 EQU P1.4 DATE3 EQU P1.5 DATE4 EQU P1.6 DATE1 EQU P1.7 MON1 EQU P3.0 MON2 EQU P3.1 DSEG ; This is internal data memory ORG 20H ; Bit adressable memory DATES: DS 1 DAY: DS 1 MONTH: DS 1 SEL: DS 1 TEMP: DS 1 STACK: DS 1 ; Stack begins here CSEG ; Code begins here ;---------==========----------==========---------=========--------- ; PROCESSOR INTERRUPT AND RESET VECTORS ;---------==========----------==========---------=========--------- ORG 00H ; Reset ; ---------==========----------==========---------=========--------- ; Main routine ; ---------==========----------==========---------=========--------- SETB P3.1 SETB P3.0 SETB DATE1 ;Switch on first column for date CLR DATE2 CLR DATE3 CLR DATE4 SETB MON1 CLR MON2 CLR DAY_CLK CLR DATE_CLK CLR MON_CLK SETB DAY_RST SETB DATE_RST SETB MON_RST NOP CLR DAY_RST CLR DATE_RST CLR MON_RST MOV SEL,#01H MOV DAY,#01H MOV DATES,#01H MOV MONTH,#01H UPO: SETB SELECT SETB UP SETB DOWN JNB SELECT,HJ1 JNB UP,HJ2 JNB DOWN,HJ34 AJMP UPO ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& ; SELECT BUTTON ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& HJ34: AJMP HJ3 HJ1: JNB SELECT,$ ;SELECT BUTTON CALL DELAY JNB SELECT,$ MOV A,SEL CJNE A,#03H,FG1 MOV SEL,#00H FG1: INC SEL AJMP UPO ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& ; UP BUTTON ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& HJ2: JNB UP,$ CALL DELAY JNB UP,$ MOV A,SEL CJNE A,#01H,FVB1 INC DAY ;day MOV A,DAY CJNE A,#08H,BN1 ;chk for day is 8 SETB DAY_RST NOP CLR DAY_RST MOV DAY,#01H AJMP UPO BN1: SETB DAY_CLK CALL DELLAY CLR DAY_CLK AJMP UPO ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& ; ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& FVB1: CJNE A,#02H,FVB2 ;date DCD2: INC DATES MOV A,DATES CJNE A,#01,CVS1 SETB DATE_RST NOP CLR DATE_RST SETB DATE1 CLR DATE2 CLR DATE3 CLR DATE4 AJMP DDVN CVS1: CJNE A,#11,CVS2 SETB DATE2 CLR DATE1 CLR DATE3 CLR DATE4 AJMP DDVN CVS2: CJNE A,#21,CVS3 SETB DATE3 CLR DATE1 CLR DATE2 CLR DATE4 AJMP DDVN CVS3: CJNE A,#31,CVS4 SETB DATE4 CLR DATE1 CLR DATE2 CLR DATE3 AJMP DDVN CVS4: CJNE A,#32,DDVN SETB DATE1 CLR DATE4 CLR DATE2 CLR DATE3 CLR DATE_CLK SETB DATE_RST NOP CLR DATE_RST MOV DATES,#01H AJMP DSD2 DDVN: SETB DATE_CLK CALL DELLAY CLR DATE_CLK DSD2: AJMP UPO ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& ; ;&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& FVB2: CJNE A,#03H,DSD2 ;month INC MONTH MOV A,MONTH CJNE A,#01,CVS91 SETB MON_RST NOP CLR MON_RST SETB MON1 CLR MON2 AJMP DADVN CVS91: CJNE A,#11,CVS92 SETB MON2 CLR MON1 AJMP DADVN CVS92: CJNE A,#13,DADVN SETB MON1 CLR MON2 CLR MON_CLK SETB MON_RST NOP CLR MON_RST MOV MONTH,#01H AJMP UPO DADVN: SETB MON_CLK CALL DELLAY CLR MON_CLK AJMP UPO HJ3: CALL HDAY_DELAY CALL THIRTY0NE ;march CALL THIRTY ;April CALL THIRTY0NE ;may CALL THIRTY ;june CALL THIRTY0NE ;july CALL THIRTY0NE ;august CALL THIRTY ;sep CALL THIRTY0NE ;oct CALL THIRTY ;NOV CALL THIRTY0NE ;DEC AJMP HJ3 HDAY_DELAY: MOV TMOD,#01H ;time delay for 1 Day MOV R4,#03 ;count for 1 DAY (24 for 1 day) AP21: MOV R5,#60 ;count for 1 hour (60 for 1 Hour) AP1: MOV R6,#60 ;count for 1 min (60 FOR 1 MIN) AP: MOV R7,#20 ;start timer for 1 SEC (20 for 1 Sec (50ms X 20=1 sec) AP2: MOV TL0,#0AAH MOV TH0,#3CH SETB TR0 JNB TF0,$ CLR TR0 CLR TF0 DJNZ R7,AP2 DJNZ R6,AP DJNZ R5,AP1 DJNZ R4,AP21 RET ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ; THIRTY ONE DAYS ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ THIRTY0NE: INC DATES MOV A,DATES CJNE A,#01,ACVS1 SETB DATE_RST NOP CLR DATE_RST SETB DATE1 CLR DATE2 CLR DATE3 CLR DATE4 AJMP ADDVN ACVS1: CJNE A,#11,ACVS2 SETB DATE2 CLR DATE1 CLR DATE3 CLR DATE4 AJMP ADDVN ACVS2: CJNE A,#21,ACVS3 SETB DATE3 CLR DATE1 CLR DATE2 CLR DATE4 AJMP ADDVN ACVS3: CJNE A,#31,ACVS4 SETB DATE4 CLR DATE1 CLR DATE2 CLR DATE3 AJMP ADDVN ACVS4: CJNE A,#32,ADDVN SETB DATE1 CLR DATE4 CLR DATE2 CLR DATE3 CLR DATE_CLK SETB DATE_RST NOP CLR DATE_RST MOV DATES,#01H CALL INC_MONTH CALL DAY_DELAY RET ADDVN: SETB DATE_CLK CALL DELLAY CLR DATE_CLK ADSD2: INC DAY ;day MOV A,DAY CJNE A,#08H,BNA1 ;chk for day is 8 SETB DAY_RST NOP CLR DAY_RST MOV DAY,#01H AJMP UPO1 BNA1: SETB DAY_CLK CALL DELLAY CLR DAY_CLK AJMP UPO1 UPO1: CALL DAY_DELAY AJMP THIRTY0NE ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ; THIRTY DAY PROGRAM ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ THIRTY: INC DATES MOV A,DATES CJNE A,#01,CACVS1 SETB DATE_RST NOP CLR DATE_RST SETB DATE1 CLR DATE2 CLR DATE3 CLR DATE4 AJMP CADDVN CACVS1: CJNE A,#11,CACVS2 SETB DATE2 CLR DATE1 CLR DATE3 CLR DATE4 AJMP CADDVN CACVS2: CJNE A,#21,CACVS3 SETB DATE3 CLR DATE1 CLR DATE2 CLR DATE4 AJMP CADDVN CACVS3: CJNE A,#31,CADDVN SETB DATE1 CLR DATE4 CLR DATE2 CLR DATE3 CLR DATE_CLK SETB DATE_RST NOP CLR DATE_RST MOV DATES,#01H CALL INC_MONTH CALL DAY_DELAY RET CADDVN: SETB DATE_CLK CALL DELLAY CLR DATE_CLK CADSD2: INC DAY ;day MOV A,DAY CJNE A,#08H,CBNA1 ;chk for day is 8 SETB DAY_RST NOP CLR DAY_RST MOV DAY,#01H AJMP CUPO1 CBNA1: SETB DAY_CLK CALL DELLAY CLR DAY_CLK AJMP CUPO1 CUPO1: CALL DAY_DELAY AJMP THIRTY ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ; ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ INC_MONTH: INC MONTH MOV A,MONTH CJNE A,#01,ACVS91 SETB MON_RST NOP CLR MON_RST SETB MON1 CLR MON2 AJMP ADADVN ACVS91: CJNE A,#11,ACVS92 SETB MON2 CLR MON1 AJMP ADADVN ACVS92: CJNE A,#13,ADADVN SETB MON1 CLR MON2 CLR MON_CLK SETB MON_RST NOP CLR MON_RST MOV MONTH,#01H AJMP AUPO ADADVN: SETB MON_CLK CALL DELLAY CLR MON_CLK AUPO: RET ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ DAY_DELAY: MOV TMOD,#01H ;time delay for 1 Day MOV R4,#24 ;count for 1 DAY (24 for 1 day) TP2: MOV R5,#60 ;count for 1 hour (60 for 1 Hour) TP1: MOV R6,#60 ;count for 1 min (60 FOR 1 MIN) TP: MOV R7,#20 ;start timer for 1 SEC (20 for 1 Sec (50ms X 20=1 sec) UP2: MOV TL0,#0AAH MOV TH0,#3CH SETB TR0 JNB TF0,$ CLR TR0 CLR TF0 DJNZ R7,UP2 DJNZ R6,TP DJNZ R5,TP1 DJNZ R4,TP2 RET ;@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ;******************************************************************** ; DELAY PROGRAMS ;******************************************************************** DELLAY: MOV R5,#0FFH DJNZ R5,$ RET ;******************************************************************** DELAY: MOV R0,#1FH INLOP: MOV R1,#0FFH DJNZ R1,$ DJNZ R0,INLOP RET ;******************************************************************** END

PICkit3 Standalone Programmer Application

 This is a beta version it may cause any harm, but one never knows where the bugs are hiding. Please use accordingly.

Not all features are implemented yet. Anything not explicitly disabled should work, though. 

PICkit3 Programmer Download Here