I'm assuming this is the hardware you have, so I broke out my rfPIC eval kit, and played
a bit. Give these a try.
Receiver example;
Transmitter example;Code:'**************************************************************** '* Name : rfPIC_RX.BAS * '* Author : B. Reynolds * '* Notice : Copyright (c) 2007 Reynolds Electronics * '* : All Rights Reserved * '* Date : 10/09/2007 * '* Version : 1.0 (Momentary decoder version) * '* Notes : 2-Bit decoder for Microchip RF dev system * '* : with rfRXD0420 module installed in PICkit 1 board * '**************************************************************** @ DEVICE PIC16F676,MCLR_OFF,INTRC_OSC_NOCLKOUT,WDT_OFF,BOD_OFF @ DEVICE PWRT_ON,PROTECT_OFF DEFINE OSC 4 DEFINE NO_CLRWDT 1 ' Watchdog timer is disabled, so we don't need to reset it DEFINE OSCCAL_1K 1 ' load factory calibration value DEFINE INTHAND RESET_VT ' Interrupt on Timer1 overflow to reset outputs in 65.5mS ' if no serial data received in this time period SYMBOL D_IN = PORTC.1 ' data input pin SYMBOL TMR1IF = PIR1.0 ' Timer1 overflow interrupt flag (reset in int handler) SYMBOL TMR1IE = PIE1.0 ' Timer1 interrupt enable bit 'Variables for saving state in interrupt handler wsave VAR BYTE $5F system ' Saves W ssave VAR BYTE bank0 system ' Saves STATUS psave VAR BYTE bank0 system ' Saves PCLATH fsave VAR BYTE bank0 system ' Saves FSR ' Working variables MATCH VAR BYTE bank0 system ' Match variable DAT_OUTB VAR BYTE ' Holds decoded data for output DAT_IN1 VAR BYTE ' 1st Data byte DAT_IN2 VAR BYTE ' 2nd Data byte for verify CHK_SUM VAR BYTE ' Holds checksum received CheckSum VAR BYTE ' Computed checksum of all bytes received LOOPS VAR BYTE ' Loop var ' Constants Synch CON "~" ' 01111110 synch byte N2400 CON 16780 ' 2400 bps inverted N4800 CON 188 ' 4800 bps inverted ' hardware init PORTA = 0 TRISA = %00111001 ' RA1 and RA2 are LED outputs PORTC = 0 ' Clear outputs on power-up TRISC = %00111110 ' RC1 = RF input IOC = 0 ' Interrupt on change disabled VRCON = 0 ' Comparator Vref disabled CMCON = 7 ' Disable comparators ANSEL = 0 ' disable A/D OPTION_REG = 128 ' Pull-ups off ' Setup Timer1 for resets after ~65.5mS T1CON = %00000000 ' Internal clock, 1:1 prescale, Timer1 off for now TMR1L = 0 TMR1H = 0 ' Timer1 low & high bytes cleared TMR1IF = 0 ' Clear Timer1 overflow flag before enabling interrupt TMR1IE = 1 ' Enable Timer1 overflow interrupt INTCON = %11000000 ' Global & peripheral ints enabled MATCH = 0 ' Clear match count GOTO MAIN ' Jump over int handler ASM ; Timer1 overflow interrupt resets outputs when no valid key press ; is detected within ~65mS RESET_VT movwf wsave ; Save W swapf STATUS, W ; Swap STATUS to W (swap avoids changing STATUS) clrf STATUS ; Clear STATUS movwf ssave ; Save swapped STATUS movf PCLATH, W ; Move PCLATH to W movwf psave ; Save PCLATH movf FSR, W ; Move FSR to W movwf fsave ; Save FSR ; Do interrupt stuff here bcf T1CON,TMR1ON ; Stop Timer1 clrf TMR1L ; Clear low byte clrf TMR1H ; Clear high byte bcf PIR1,TMR1IF ; Clear Timer1 interrupt flag bit clrf PORTA ; Clear outputs on button release clrf MATCH ; Clear match variable ; Restore FSR, PCLATH, STATUS and W registers movf fsave, W ; retrieve FSR value movwf FSR ; Restore it to FSR movf psave, W ; Retrieve PCLATH value movwf PCLATH ; Restore it to PCLATH swapf ssave, W ; Get swapped STATUS value (swap to avoid changing STATUS) movwf STATUS ; Restore it to STATUS swapf wsave, F ; Swap the stored W value swapf wsave, W ; Restore it to W (swap to avoid changing STATUS) bsf T1CON,TMR1ON ; Re-enable Timer1 before exiting interrupt handler retfie ; Return from the interrupt ENDASM MAIN: ' Fire up Timer1 before entry to serial input routine T1CON.0 = 1 ' at 4MHz Timer1 overflows in 65536 * 1uS (~65.5mS) if no Synch byte ' and serial data arrive on time. SERIN2 timeout & label options ' are useless with a noisy RF receiver output - as noise continually ' resets the timeout period causing it to hang forever. ' Wait for Synch byte, then get new inbound data & checksum SERIN2 D_IN,N2400,[WAIT(Synch),DAT_IN1,DAT_IN2,CHK_SUM] T1CON.0 = 0 ' Stop Timer1 once we've received data TMR1L = 0 ' Clear low byte TMR1H = 0 ' Clear high byte ' / **** Begin data validation **** / ' Calculate checksum by adding 2 data bytes together CheckSum = DAT_IN1 + DAT_IN2 ' Test new checksum against one received in CHK_SUM IF CheckSum != CHK_SUM THEN MAIN ' Failed checksum, return ' Test data bytes for match IF (DAT_IN1) != (DAT_IN2) THEN MAIN ' Failed data comparison, return MATCH = MATCH + 1 ' We have a match so increment match count IF MATCH = 2 THEN DECODE ' Everything matched twice, we're good GOTO Main ' Else do it all over ' Everything looking good - so place new data on outputs DECODE: ' Place decoded values on port pins.. PORTA = DAT_IN1 & %00000110 DAT_IN1 = !DAT_IN2 ' Destroy the match MATCH = 0 GOTO MAIN END
You should be able to modify these pretty easily for your own application.Code:'**************************************************************** '* Name : rfPIC_TX.BAS * '* Author : B. Reynolds * '* Notice : Copyright (c) 2007 Reynolds Electronics * '* : All Rights Reserved * '* Date : 10/09/2007 * '* Version : 1.0 * '* Notes : 2-BIT Encoder for remote control with the * '* : rfPIC12F675 on Microchip rfPIC demo board * '**************************************************************** @ DEVICE PIC12F675,MCLR_OFF,INTRC_OSC_NOCLKOUT,WDT_OFF,BOD_OFF @ DEVICE PWRT_ON,PROTECT_OFF ' With rfRXD0420 module installed in PICkit 1 board; ' SW1 toggles LED D6 on PICkit 1 board ' SW2 toggles LED D7 on PICkit 1 board DEFINE OSC 4 DEFINE NO_CLRWDT 1 DEFINE OSCCAL_1K 1 SYMBOL D_OUT = GPIO.2 ' RF serial data output SYMBOL E_OUT = GPIO.5 ' RF transmitter enable output DAT_OUT VAR BYTE ' Holds 8-bit data byte LOOPS VAR BYTE ' Loop var CHK_SUM VAR BYTE ' Holds calculated checksum of outbound data BAUD VAR WORD ' Holds baud rate ' Constants PreAmble CON $A5 ' 10100101 preamble Synch CON "~" ' 01111110 synch byte N4800 CON 188 ' 4800 bps N2400 CON 16780 ' 2400 bps GUARD CON 5 ' 5mS guard time pause ' hardware init GPIO = 0 ' Everything off on boot ' GPIO.2=data out, GPIO.5=RF enable, GPIO.3,4=SW1/SW2 switch inputs (rfPIC board) TRISIO = %00011011 ' ANSEL = 0 ' Disable A/D INTCON = %00001000 ' Enable port change wakeup from sleep WPU = %00010000 ' pull-up on for GPIO.4 (external pull-up already on GPIO.3) IOC = %00011000 ' Wakeup on change enabled for GPIO.3,4 VRCON = 0 ' Disable internal Vref CMCON = 7 ' Disable comparators OPTION_REG = 0 ' Pull-ups on D_OUT = 0 ' Idles low for inverted serial output E_OUT = 0 ' Enable for RF transmitter=0 (transmiter off) BAUD = N2400 ' Set baud rate here Main: ' Read port to clear missmatch, if with no buttons pressed, then ' clear int-on-change flag & snooze until wake up on change. This ' conserves battery power on the demo board with 3V coin cell. IF (GPIO.3=1) AND (GPIO.4=1) THEN ' pins will be 0 only when buttons are pressed E_OUT=0 ' Disable transmitter INTCON.0 = 0 ' No buttons down, so clear int on change flag @ SLEEP ' and start snoozin..zzzzzzzzzzz @ NOP ' Do nothing for 1st instruction on wake-up ENDIF E_OUT=1 ' Enable transmitter (+ lights RFEN LED on demo board) PAUSEUS 25 ' Allow RF stage to stabilize ' Button pressed (or being held down), so keep going Encode: ' Only DAT_OUT bits 1 and 2 are used. We add a few 1's in bit ' positions 0,3,5,7 to balance out the data packet being sent. DAT_OUT = %10101001 ' Get data on button inputs & invert 0's to 1's DAT_OUT.0[1]=~GPIO.3 DAT_OUT.0[2]=~GPIO.4 INTCON.0 = 0 ' Clear int on change flag ' Build checksum of 2 data bytes CHK_SUM = (DAT_OUT * 2) Transmit: SEROUT2 D_OUT,BAUD,[PreAmble,Synch,DAT_OUT,DAT_OUT,CHK_SUM] PAUSE GUARD ' 5mS guard time gives decoder time to respond,calculate,change,etc. GOTO Main END
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