单片机红外壁障传感器制作

WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20001 Dallas Personal Robotics Group IR Detector By: Darren Sawicz Original Documentation By: Jeff Koenig his document is an update reflecting the changes made to Jeff Koenig's Infrared detector circuit. The assembly code and circuit are unchanged but the printed circuit artwork and documentation have been upgraded to make assembly easier. Theory of Operation The PIC12C509 generates a 38 kHz square wave, which delivers current to the infrared LEDs. The infrared energy is then reflected off of an obstacle, if present, and is detected by the Sharp IR receiver. The program does the following: 1. Flash the 38 kHz square wave through the Left infrared LED for 600 microseconds. 2. Check the Sharp detector – if it detects IR light, go to step 3. If not, go to step X. 3. Good! A reflection was detected. But, it might be from another source, so we will turn off the Left LED and see if the Sharp detector is sti ll seeing infrared il lumination (from another source). 4. Keep the Left infrared LED off for 600 microseconds. 5. Check the Sharp detector – there shouldn’t be any IR detected, since we turned off the LED. If there is IR detected, go to step X, 6. A valid reflection was detected, so turn on the left LED (red) and bring header pin 4 high. Skip to step 8. 7. No valid detection was made. 8. Return to step one, but this time substitute “right” for “left” The New Board The new circuit board is smaller than Jeff Koenig's original board. Each new board measures 1.5" x 1". This allows 16 small boards to be cut from a single 4" x 6" board. The original ASCII artwork showed none of the component connections, only component layout. I created a schematic drawing of the circuit to make it easier to see how the circuit is connected. The schematic is included on the last page. T WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20002 12C509 PIC Detector Module IR IR LED 5 - Pin Header IR LED RED LED 1k Po ten tio me ter 1k Po ten tio me ter Foil Pattern R2R1 JP1 D3 RED LED D2 D4 D1 R3R4 +5V GND /INHIBIT Left Detect Right Detect The new board is laid out as follows: The signals available at the header pins are: 1. +5VDC - Supply +5 VDC to this pin. 2. GND - Supply ground to this pin. 3. /INHIBIT - If you want the IRPROX unit to stop pulsing infrared light, use your micro to take this pin low (ground). 4. LEFT DETECT - Output from the IRPROX module. High (+5V) if reflection detected. 5. RIGHT DETECT - Output from the IRPROX module. High (+5V) if reflection detected. Parts List The parts list has been revised to include part numbers from distributors in the Winnipeg Area. Part Description Qty. Distributor Part Number IR Detector Board 1 Winnipeg Area Robotics Society U1 - PIC 12C508 or 12C509 1 Active # 185-0084Digi-Key # PIC12C508A-04/P-ND JP1 - 5 x 1 Header 1 Active # 666-2758Digi-Key # S1012-36-ND R1 & R2 - 330 Ohm Resistor 2 Digi-Key # 330QBK-NDActive – 330 ohm D1 & D2 - Red LED 2 Digi-Key # 67-1402-NDActive # 303-3033 R3 & R4 - 1k Potentiometer 2 Active # 468-7582 Sharp IR Module 36 kHz 1 Radio-Shack # 276-137 D3 & D4 - IR LED 2 Active # LD271Digi-Key # QED423QT-ND For M ore Information Please Visit: http://www.winnipegrobotics.com WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20003 Appendix A Source Code ; TITLE 'Infra Red Proximity Detector - uses Sharp GP1U581Y' ; LIST P = 12C509, F = INHX8M ; P12C509.INC Standard Header File, Version 1.02 Microchip Technology, Inc. NOLIST ;========================================================================== ; Verify Processor ;========================================================================== IFNDEF __12C509 MESSG "Processor-header file mismatch. Verify selected processor." ENDIF ;========================================================================== ; Register Definitions ;========================================================================== W EQU H'0000' F EQU H'0001' ;----- Register Files ----------------------------------------------------- INDF EQU H'0000' ; Uses FSR to address data mem. TMR0 EQU H'0001' ; 8 bit real time clock/counter PCL EQU H'0002' ; Low order 8 bits of PC STATUS EQU H'0003' ; STATUS FSR EQU H'0004' ; Indirect data memory addr pointer OSCCAL EQU H'0005' ; Calibration data for osc. GPIO EQU H'0006' ; General Purpose I/O ;----- STATUS Bits -----------Page 14-------------------------------------- GPWUF EQU H'0007' ; GPIO reset bit PA0 EQU H'0005' ; Program Page preselect NOT_TO EQU H'0004' ; Time Out bit NOT_PD EQU H'0003' ; Power Down bit ZERO EQU H'0002' ; Zero bit DC EQU H'0001' ; Digit carry/*borrow bit CARRY EQU H'0000' ; carry/*borrow bit ;----- OPTION Bits -----------Page 15-------------------------------------- NOT_GPWU EQU H'0007' ; Enable wake-up on pin change NOT_GPPU EQU H'0006' ; Enable weak pull-ups T0CS EQU H'0005' ; Timer0 clock source select T0SE EQU H'0004' ; Timer0 sources edge select PSA EQU H'0003' ; Prescalar assignment bit PS2 EQU H'0002' ;\ PS1 EQU H'0001' ; > Prescalar rate select bits PS0 EQU H'0000' ;/ ;========================================================================== ; RAM Definition ;========================================================================== __MAXRAM H'3F' ;========================================================================== ; Configuration Bits ;========================================================================== _MCLRE_ON EQU H'0FFF' _MCLRE_OFF EQU H'0FEF' _CP_ON EQU H'0FF7' _CP_OFF EQU H'0FFF' _WDT_ON EQU H'0FFF' _WDT_OFF EQU H'0FFB' _LP_OSC EQU H'0FFC' _XT_OSC EQU H'0FFD' _IntRC_OSC EQU H'0FFE' _ExtRC_OSC EQU H'0FFF' __CONFIG ( _MCLRE_OFF & _CP_OFF & _WDT_OFF & _IntRC_OSC ) ;========================================================================== ; Program Variables ;========================================================================== WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20004 CONSTANT DELAYTIME=D'150' ; Timer value #define LEFTDETECT GPIO,5 ; Pin 2 = GP5 = Bit 5 #defineRIGHTDETECT GPIO,4 ; Pin 3 = GP4 = Bit 4 #define INHIBIT GPIO,3 ; Pin 4 = GP3 = Bit 3 NOTE: INPUT ONLY! #define RIGHTLED GPIO,2 ; Pin 5 = GP2 = Bit 2 #define IRDETECT GPIO,1 ; Pin 6 = GP1 = Bit 1 #define LEFTLED GPIO,0 ; Pin 7 = GP0 = Bit 0 LIST WAIT EQU 9 ; Location for counter for time delay loop ;========================================================================== ; Code Begins ;========================================================================== start ORG H'00' ; MOVLW H'7F' ; -- USED FOR OFFSET IN ERASABLE PARTS --- MOVWF OSCCAL ; Store the factory osc. calibration value MOVLW B'00001010' ; Set pins 4 as inputs, 2,3,5,6,7 as outputs TRIS GPIO ; Configure pins as either I or O MOVLW B'00000000' ; Set OPTION bits OPTION ; Implement OPTION bits BCF LEFTLED BCF LEFTDETECT BCF RIGHTLED BCF RIGHTDETECT main noflash BTFSC INHIBIT ; Don't flash the IR Leds if the INHIBIT pin is low GOTO do_left ; BTFSC IRDETECT ; Check the IR detector GOTO NF1 GOTO NF2 NF1 BCF LEFTDETECT ; No 38 KHz IR detected BCF RIGHTDETECT ; So turn on off right and left LED NF2 BSF LEFTDETECT ; 38 KHz IR detected BSF RIGHTDETECT ; So turn on right and left LED GOTO noflash ; do_left CALL pulseleft ; Pulse the left IR LED at 38 KHz for 600 microseconds BTFSC IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_left ; IR detector didn't sense reflection with Left LED on CALL delayloop ; Wait 600 microseconds BTFSS IRDETECT ; Read the Sharp Module. Skip next inst. if no detection (0=detect) GOTO no_left ; Now check for an obstacle on the right side CALL pulseleft ; Pulse the left IR LED at 38 KHz for 600 microseconds BTFSC IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_left ; IR detector didn't sense reflection with Left LED on CALL delayloop ; Wait 600 microseconds BTFSS IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_left ; Now check for an obstacle on the right side CALL pulseleft ; Pulse the left IR LED at 38 KHz for 600 microseconds WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20005 BTFSC IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_left ; IR detector didn't sense reflection with Left LED on BSF LEFTDETECT ; Turn on the left Visible LED GOTO do_right ; no_left ; No obstacle to the left, so BCF LEFTDETECT ; Turn off the left visible LED do_right CALL pulseright ; Pulse the right IR LED at 38 KHz for 600 microseconds BTFSC IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_right ; IR detector didn't sense reflection with Right LED on CALL delayloop ; Wait 600 microseconds BTFSS IRDETECT ; Read the Sharp Module. Skip next inst. if no detection (0=detect) GOTO no_right ; Now check for an obstacle on the left side CALL pulseright ; Pulse the right IR LED at 38 KHz for 600 microseconds BTFSC IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_right ; IR detector didn't sense reflection with Right LED on CALL delayloop ; Wait 600 microseconds BTFSS IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_right ; Now check for an obstacle on the left side CALL pulseright ; Pulse the right IR LED at 38 KHz for 600 microseconds BTFSC IRDETECT ; Read the Sharp Module. Skip next inst. if detection (0=detect) GOTO no_right ; IR detector didn't sense reflection with Right LED on BSF RIGHTDETECT ; Turn on the left Visible LED GOTO main no_right ; No obstacle to the right, so BCF RIGHTDETECT ; Turn off the right visible LED GOTO main delayloop ;------------------------ MOVLW D'195' ; MOVWF WAIT ; This creates a 600 microsecond delay loop ; NOP ; DECFSZ WAIT,F ; goto loop ; RETLW 0 ;------------------------ pulseleft ;------------------------ MOVLW D'24' ; MOVWF WAIT ; Pulses the left IR led at 38 KHz leloop BSF LEFTLED ; for 600 microseconds NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; BCF LEFTLED ; NOP ; WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20006 NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; DECFSZ WAIT,F ; GOTO leloop ; RETLW 0 ;------------------------ pulseright ;------------------------ MOVLW D'24' ; MOVWF WAIT ; Pulses the right IR led riloop BSF RIGHTLED ; for 600 microseconds NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; BCF RIGHTLED ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; NOP ; DECFSZ WAIT,F ; GOTO riloop ; RETLW 0 ;------------------------ end WINNIPEG AREA ROBOTICS SOCIETY MARCH 22, 20007 APPENDIX B Hex Listing :1000000025000A0C0600000C02000604A6044604A3 :1000100086046606130A26060E0A100AA60486043B :10002000A6058605090A3E092606240A3809260778 :10003000240A3E092606240A38092607240A3E090E :100040002606240AA605250AA6045A092606360A03 :1000500038092607360A5A092606360A38092607B5 :10006000360A5A092606360A8605090A8604090A46 :10007000C30C29000000E9023A0A0008180C290004 :100080000605000000000000000000000000000065 :100090000000000000000000060400000000000056 :1000A0000000000000000000000000000000E90265 :1000B000400A0008180C2900460500000000000056 :1000C0000000000000000000000000000000000030 :1000D00046040000000000000000000000000000D6 :0C00E000000000000000E9025C0A0008BB :021FFE00EA0FE8 :00000001FF 1 2 3 4 A B C D 4321 D C B A 1 Winnipeg Area Robotics Society 1 WARS002 0 21-Mar-2000 22:22:55 Title Size: Number: Date:Drawn By: Darren Sawicz Revision: Sheet ofTime: Letter DPRG IR Proximity Detector Meetings at U of M Saint John's College Room 118 92 Dysart Road VDD 1 GP5/OSC1 2 GP4/OSC2 3 GP3//MCLR 4 GP2/T0CKI 5GP1 6GP0 7VSS 8 U1 PIC12C509 V CC 2 V ou t 1 G N D 3 Det1 IR DETECTOR MODULE R1 330 R2 330 D1 Red LED D2 Red LED R3 1k R4 1k D3 IR LED D4 IR LED Left Detect Right Detect /INHIBIT +5V +5V 1 2 3 4 5 JP1 5 Pin Header +5V /INHIBIT Left Detect Right Detect Theory of Operation The signals available at the header pins are: Parts List APPENDIX A - Source Code APPENDIX B - Hex Listing SCHEMATIC