Hi Gavin,
I'm just guessing, but are you using a Microchip rfPIC dev kit?
|
Hi Gavin,
I'm just guessing, but are you using a Microchip rfPIC dev kit?
|
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
|
RFSerin Problem
Hi Bruce,
Many thanks I will give it a bash ;-), regards, Gavin
|
Hi,
I'm a beginner in PIC programming and now struggling to program rfPIC12F675. I'm confused on how TRISIO assign input and output.
movlw b'00010000' ; set GP<4> as digital inputs and other bits as output
movwf trisio ; and set others as outputs/mclr/clkout/osc
However, when I try to simulate it, and try to observe the output (we fire the GP4 as high),
it seems that the output is 0 all the time.
Other than setting the trisio, do I need to call any other instructions to make sure the data is being read in - send to modulation - and then output accordingly.
I'm a bit lost now. Hope that you can help
|
The data sheet has everything you're looking for.
And if you're looking for examples in Microchip assembler, then check the Microchip website for rfPIC examples. Here's a direct link to rfPIC examples; http://www.microchip.com/stellent/id...cName=en010060
|
Thanks for that. It is useful!
|
tranmitter demo program
im looking at the demo program for development kits transmitter and receiver rfpic12675 and receiver rf rxd XXX. im trying to apply the same program to my telemtry project but with digital input.
i dont understand the part of program which under head transmitter loop. do we need to do the loop if our input is digital? and what about the '' rrf ' and 'bnz' instruction? rotate right flag?
i don't understand the TZnextbit too? im so lost right now. can anyone explain this to me?
thanks
Members who have read this thread : 0You do not have permission to view the list of names.
Posting Permissions
Bookmarks