RFM12 with picbasic_pro

[iw2fvo]

Good day to all of you in the forum,
I would like to know if there ia a sample picbasic pro program capable of operating the RFM12 receiver transmitter.
Any hel is appreciated.
Thanks
Ambrogio

[craigwb]

Hi Ambrogio

Have a look at the thread http://www.picbasic.co.uk/forum/showthread.php?t=8962 there is a writeup on the RFM12 Transceiver there.
Hope this helps
Craig

[prstein]

Hello Ambrogio,

I've worked with the RFM22B, which I believe is similar. I can post some demo code if you think it is similar enough.

Best Regards,
Paul

[iw2fvo]

Thanks very much for having reply to my mail,
Yes, it will be very useful to me if you can post your code.
My e_mail is : [email protected]
Best regards,
Ambrogio



Hello Ambrogio,

I've worked with the RFM22B, which I believe is similar. I can post some demo code if you think it is similar enough.

Best Regards,
Paul

[prstein]

Yes, it will be very useful to me if you can post your code.


Here you go. Please let us know how it works out.


'************************************************* ***************
'* Name : Transceiver.pbp *
'* Author : Paul R. Steinmeyer *
'* Notice : Copyright (c) 2010 [select VIEW...EDITOR OPTIONS] *
'* : All Rights Reserved *
'* Date : 11/02/2010 *
'* Version : 1.0 *
'* Notes : Target uC: 16F88, using 18F1320 *
'* : Interface with RFM22 *
'* : Waits in RX Mode unless button is pressed, at *
'* : which point it transmits the packet and returns *
'* : to RX mode. *
'* : At any valid packet reception the LED blinks *
'* : *
'* : Un-rem lines with SEROUT2 for debugging serial *
'* : transmissions at 9600 baud *
'* : *
'* : *
'************************************************* ***************


'------------------------------------------------------------------------------------------------------------------------------------
' # Name |I/O| Alias | Var | Description
'------------------------------------------------------------------------------------------------------------------------------------
' 1 RA0/AN0 |D 1| nButton | | Goes low when button is pressed
' 2 RA1/AN1 |D 0| LED | | LED on when high
' 3 RA4/T0CKI |D 1| | | N/C
' 4 RA5/MCLR |D 1| | | N/C
' 5 Vss | | | | Ground
' 6 RA2/AN2 |D 1| | | N/C
' 7 RA3/AN3 |D 1| | | N/C
' 8 RB0/AN4 |D 1| nIRQ | | Goes low on interrupt from RFM
' 9 RB1/TX | 0| nSel | | Bring low to select RFM
'------------------------------------------------------------------------------------------------------------------------------------
'10 RB4/RX |D 1|SDO | | Input from RFM output
'11 RB5/SS |D 0|TX_ANT | | Selector for TX Mode
'12 RB6/T1CKI |D 0|RX_ANT | | Selector for RX Mode
'13 RB7 |D 0| | | N/C
'14 Vdd | | | | +3V
'15 RA6/OSC2 |D 1| | | N/C
'16 RA7/OSC1 |D 1| | | N/C
'17 RB2 |D 0|SCK | | Clock signal to RFM
'18 RB3 |D 0|SDI | | Output to RFM input
'------------------------------------------------------------------------------------------------------------------------------------
'Be sure to REM out the line "__CONFIG _CONFIG1H, _XT_OSC_1H" in the \PBP\18F1320.INC file!
'@ __CONFIG _CONFIG1H, _INTIO2_OSC_1H
'@ __CONFIG _CONFIG3H, _MCLRE_OFF_3H


'**********
' DEFINES
'**********
DEFINE OSC 4


'***********
' CONSTANTS
'***********
PacketSize CON 3


'****************
' Hardware Setup
'****************
'All Ports Digital
'un-rem this line for 18F1320...
ADCON1 = $7F
'...or un-rem these two for 16F88
'ANSEL = 0
'CMCON = 7


OSCCON = 100000 '4MHz
PORTA = 110111
TRISA = 000001
PORTB = 000010
TRISB = 010001


'*********
' ALIASES
'*********
nButton VAR PORTA.0
LED VAR PORTA.1
SDO VAR PORTB.4
SDI VAR PORTB.3
SCK VAR PORTB.2
nSEL VAR PORTB.1
nIRQ VAR PORTB.0
TX_ANT VAR PORTB.5
RX_ANT VAR PORTB.6


'***********
' VARIABLES
'***********
nAddress VAR BYTE
nOutData VAR BYTE
nInData VAR BYTE
nStatus1 VAR BYTE
nStatus2 VAR BYTE
i var byte
anRxBuf var byte[35] 'at least 2x the packet length
anTxBuf VAR BYTE[PacketSize]
nCheckSum var byte


'**********************
' Initialize Variables
'**********************
nSEL = 1
LED = 1
PAUSE 1000
LED = 0


for i = 0 to 34
anRxBuf[i] = $ff
next i


for i = 0 to PacketSize-1
anTxBuf[i] = $30+i
next i

'Initialize the RFM22 Registers
GOSUB InitRFM
'Set up to receive data
GOSUB To_RX_Mode
'Jump to the main program loop
GOTO MainLoop


'************************************************* ******************************
' HELPER FUNCTIONS
'************************************************* ******************************


'Write a single byte to the RFM22
SPI_Out:
nSel = 0 'Select the RFM22
PAUSEUS 50 'Give it a moment
nAddress.7 = 1 'Tell the RFM22 we're doing a WRITE transaction
SHIFTOUT SDI,SCK,1,[nAddress,nOutData] 'Stuff the datum into the RFM22
nSel = 1 'De-select the RFM22
PAUSEUS 100 'Unnecessary?
RETURN


'Read a single byte from the RFM22
SPI_In:
nSel = 0 'Select the RFM22
PAUSEUS 50 'Give it a moment
nAddress.7 = 0 'Tell the RFM22 we're doing a READ transaction
SHIFTOUT SDI,SCK,1,[nAddress] 'First, write the ADDRESS we want to read from
SHIFTIN SDO,SCK,0,[nInData] 'Second, take in the datum
nSel = 1 'De-select the RFM22
PAUSEUS 100 'Unnecessary?
RETURN


'Send the data contained in the anTXBuf array
To_TX_Mode:
'SEROUT2 PORTA.3,49236,["Entering RX Mode...",13,10]
NAddress = $07 : noutData = $01 : GOSUB SPI_Out 'Set READY mode in RFM22
RX_ANT = 0 'Configure for transmission
TX_ANT = 1 'Configure for transmission
Pause 50 'Give it a moment
nAddress = $08 : noutData = $03 : GOSUB SPI_Out 'Tell it we want to reset the FIFO
nAddress = $08 : noutData = $00 : GOSUB SPI_Out 'Reset the FIFO
nAddress = $34 : noutData = 64 : GOSUB SPI_Out 'Set the preamble = 64nibble
nAddress = $3E : noutData = PacketSize : GOSUB SPI_Out 'Set the packet length
nCheckSum = 0
for i = 0 to PacketSize-2
nAddress = $7F : noutData = anTXBuf[i] : GOSUB SPI_Out 'Write the data to the TX FIFO
nCheckSum = nChecksum + antxbuf[i] 'Calculate the checksum
next i
nAddress = $7F : noutData = nCheckSum : GOSUB SPI_Out 'Write the checksum as the last byte
nAddress = $05 : noutData = $04 : GOSUB SPI_Out 'Enable the packet sent interrupt
nAddress = $03 : GOSUB SPI_In : nStatus1 = nInData 'Clear interrupts part 1
nAddress = $04 : GOSUB SPI_In : nStatus2 = nInData 'Clear interrupts part 2
LED = 1 'Turn on LED immediatly prior to start of transmission
nAddress = $07 : noutData = 9 : GOSUB SPI_Out 'Tell the RFM22 to start the transmission
'wait for the interrupt to tell us the transmission is complete
TXWait:
if nirq = 1 then
goto TXWait
endif
pause 100 'This pause exists only to make the LED blink long enough to see
LED = 0 'turn off the LED
RETURN


'Set up RFM22 hardware to receive mode
To_RX_Mode:
'SEROUT2 PORTA.3,49236,["Entering RX Mode...",13,10]
RX_ANT = 0 'Turn off receiver
TX_ANT = 0 'Turn off transmitter
nAddress = $03 : GOSUB SPI_In : nStatus1 = nInData 'Clear interrupts part 1
nAddress = $04 : GOSUB SPI_In : nStatus2 = nInData 'Clear interrupts part 2
nAddress = $07 : noutData = $01 : GOSUB SPI_Out 'Set READY mode in RFM22
pause 50 'Give it a moment
RX_ANT = 1 'Configure for reception
TX_ANT = 0 'Configure for reception
pause 50 'Give it a moment
GOSUB RX_Reset 'Configure RFM22 registers for reception
PAUSEUS 10 'Give it a moment
RETURN


'Configure RFM22 registers for reception
RX_Reset:
'Set READY Mode (Xtal is ON)
nAddress = $07 : noutData = $01 : GOSUB SPI_Out
'Set the RX FIFO Almost Full interrupt level to 17 (same as the packet size)
nAddress = $7E : noutData = PacketSize : GOSUB SPI_Out
'Clear the RX FIFO and disable multi-packet
nAddress = $08 : noutData = $03 : GOSUB SPI_Out
'Second write to complete clearing FIFO buffers
nAddress = $08 : noutData = $00 : GOSUB SPI_Out
'READY mode set, RX on in Manual Receiver Mode
nAddress = $07 : noutData = $05 : GOSUB SPI_Out
'Disable extra/oddball interrupts
nAddress = $06 : noutData = 000000 : GOSUB SPI_Out
'Valid Packet Received interrupt is enabled
nAddress = $05 : noutData = $02 : GOSUB SPI_Out
'Read the interrupt registers (in order to clear them)
nAddress = $03 : GOSUB SPI_In : nStatus1 = nInData
nAddress = $04 : GOSUB SPI_In : nStatus2 = nInData
RETURN


'Initial configuration of RFM22 Registers
InitRFM:
'Disable Interrupts
nAddress = $06 : noutData = $00 : GOSUB SPI_Out
'Set READY mode
nAddress = $07 : nOutData = $01 : GOSUB SPI_Out
'cap = 12.5 pF
nAddress = $09 : nOutData = $7F : GOSUB SPI_Out
'Clk output is 2 MHz
nAddress = $0A : nOutData = $05 : GOSUB SPI_Out
'GPIO0 is RX data output
nAddress = $0B : nOutData = $F4 : GOSUB SPI_Out
'GPIO1 Tx/Rx data clk output
nAddress = $0C : nOutData = $EF : GOSUB SPI_Out
'GPIO2 for MCLK output
nAddress = $0D : nOutData = $00 : GOSUB SPI_Out
'GPIO port use default value
nAddress = $0E : nOutData = $00 : GOSUB SPI_Out
'no ADC used
nAddress = $0F : nOutData = $70 : GOSUB SPI_Out
nAddress = $10 : nOutData = $00 : GOSUB SPI_Out
'no temp sensor used
nAddress = $12 : nOutData = $00 : GOSUB SPI_Out
nAddress = $13 : nOutData = $00 : GOSUB SPI_Out
'no manchester code, no data whiting, data rate < 30Kbps
nAddress = $70 : nOutData = $20 : GOSUB SPI_Out
'IF filter bandwidth
nAddress = $1C : nOutData = $1D : GOSUB SPI_Out
'AFC loop
nAddress = $1D : nOutData = $40 : GOSUB SPI_Out
'Clock Recovery
nAddress = $20 : nOutData = $A1 : GOSUB SPI_Out
nAddress = $21 : nOutData = $20 : GOSUB SPI_Out
nAddress = $22 : nOutData = $4E : GOSUB SPI_Out
nAddress = $23 : nOutData = $A5 : GOSUB SPI_Out
'Clock Recovery timing
nAddress = $24 : nOutData = $00 : GOSUB SPI_Out
nAddress = $25 : nOutData = $0A : GOSUB SPI_Out
'zero OOK counter
nAddress = $2C : nOutData = $00 : GOSUB SPI_Out
nAddress = $2D : nOutData = $00 : GOSUB SPI_Out
'slicer peak hold
nAddress = $2E : nOutData = $00 : GOSUB SPI_Out
'TX data rate (4800 baud)
nAddress = $6E : nOutData = $27 : GOSUB SPI_Out
nAddress = $6F : nOutData = $52 : GOSUB SPI_Out
'Data Access Control
nAddress = $30 : nOutData = $8C : GOSUB SPI_Out
'Header Control
nAddress = $32 : nOutData = $FF : GOSUB SPI_Out
' header 3, 2, 1,0 used for head length, fixed packet length, synchronize word length 3, 2,
nAddress = $33 : nOutData = $42 : GOSUB SPI_Out
'64 nibble = 32byte preamble
nAddress = $34 : nOutData = 64 : GOSUB SPI_Out
'0x35 need to detect 20bit preamble
nAddress = $35 : nOutData = $20 : GOSUB SPI_Out
' synchronize word
nAddress = $36 : nOutData = $2D : GOSUB SPI_Out
nAddress = $37 : nOutData = $D4 : GOSUB SPI_Out
nAddress = $38 : nOutData = $00 : GOSUB SPI_Out
nAddress = $39 : nOutData = $00 : GOSUB SPI_Out
' set tx header
nAddress = $3A : nOutData = "h" : GOSUB SPI_Out
nAddress = $3B : nOutData = "o" : GOSUB SPI_Out
nAddress = $3C : nOutData = "p" : GOSUB SPI_Out
nAddress = $3D : nOutData = "e" : GOSUB SPI_Out
' total tx 17 byte
nAddress = $3E : nOutData = PacketSize : GOSUB SPI_Out
' set rx header
nAddress = $3F : nOutData = "h" : GOSUB SPI_Out
nAddress = $40 : nOutData = "o" : GOSUB SPI_Out
nAddress = $41 : nOutData = "p" : GOSUB SPI_Out
nAddress = $42 : nOutData = "e" : GOSUB SPI_Out
' all the bits to be checked
nAddress = $43 : nOutData = $FF : GOSUB SPI_Out
nAddress = $44 : nOutData = $FF : GOSUB SPI_Out
nAddress = $45 : nOutData = $FF : GOSUB SPI_Out
nAddress = $46 : nOutData = $FF : GOSUB SPI_Out
'Reserved
nAddress = $56 : nOutData = $01 : GOSUB SPI_Out
' tx power to Max
nAddress = $6D : nOutData = $07 : GOSUB SPI_Out
' no frequency hopping
nAddress = $79 : nOutData = $00 : GOSUB SPI_Out
nAddress = $7A : nOutData = $00 : GOSUB SPI_Out
' Gfsk, fd[8] =0, no invert for Tx/Rx data, fifo mode, txclk -->gpio
nAddress = $71 : nOutData = $22 : GOSUB SPI_Out
' frequency deviation setting to 35k = 56*625
nAddress = $72 : nOutData = $38 : GOSUB SPI_Out
' no frequency offset
nAddress = $73 : nOutData = $00 : GOSUB SPI_Out
nAddress = $74 : nOutData = $00 : GOSUB SPI_Out
' frequency set to 434MHz
nAddress = $75 : nOutData = $53 : GOSUB SPI_Out
nAddress = $76 : nOutData = $64 : GOSUB SPI_Out
nAddress = $77 : nOutData = $00 : GOSUB SPI_Out


'NOTE:
'The following 5 registers are listed as RESERVED in the RFM22B v1.1
'datasheet. Try remming them if problems are experienced
nAddress = $5A : nOutData = $7F : GOSUB SPI_Out
nAddress = $59 : nOutData = $40 : GOSUB SPI_Out
nAddress = $58 : nOutData = $80 : GOSUB SPI_Out
nAddress = $6A : nOutData = $0B : GOSUB SPI_Out
nAddress = $68 : nOutData = $04 : GOSUB SPI_Out


'Clock Recovery Gearshift Override
nAddress = $1F : nOutData = $03 : GOSUB SPI_Out
PAUSEUS 1000 'Let the settings settle
return


'************************************************* ******************************
' END OF HELPER FUNCTIONS, BEGIN MAIN PROGRAM LOOP
'************************************************* ******************************
MainLoop:
'nIRQ Pin Indicates that we have received a packet
if nIRQ = 0 then 'Packet received
'Clear the interrupt
nAddress = $03 : GOSUB SPI_In : nStatus1 = nInData
nAddress = $04 : GOSUB SPI_In : nStatus2 = nInData
'Read in the data
for i = 0 to PacketSize-1
nAddress = $7F : GOSUB SPI_In : anRxBuf[i] = nInData
next i
nSel = 1 'unncecessary?
'Calculate the checksum...
nCheckSum = 0
for i = 0 to PacketSize-2
nCheckSum = nCheckSum + anRxBuf[i]
'SEROUT2 PORTA.3,49236,[Ihex2 anRxBuf[i]," "]
anRxBuf[i] = 0
next i
'SEROUT2 PORTA.3,49236,[13,10,"ChkSum=",Ihex2 anRxBuf[i],13,10]
'Verify that the calculate checksum matches the last byte in the packet
if nChecksum = anRxBuf[PacketSize-1] then
LED = 1
'SEROUT2 PORTA.3,49236,["ChkSum MATCH!",13,10]
PAUSE 500
LED = 0;
ENDIF
GOSUB rx_reset; // rx reset
endif
'Check for button press
if nButton = 0 then 'the button is pressed...
'SEROUT2 PORTA.3,49236,["Xmitting",13,10]
'Here would be a good place to load the relevant data into anTxBuf
gosub To_TX_Mode
'and return back to RX_Mode
GOSUB To_RX_Mode
endif
GOTO MainLoop

Best Regards,
Paul

[iw2fvo]

Thanks a lot Paul: it is great !

Best regards,
Ambrogio
Iw2FVO

[lyoung298]

Thanks Paul. I was looking for something similar to this.

[prstein]

Ambrogio and lyoung298,

Glad you like it. I'm pretty happy with the RFM22 and I'm glad others are using them too.

Best Regards,
Paul

[iw2fvo]

Paul,
just a question: what is the max operative range of those RFm22 devices ?
I do have a couple of RFM12b but one is broken ( shipment problem ! ) so at the moment i can not test them.
Thanks
Ambrogio




Ambrogio and lyoung298,

Glad you like it. I'm pretty happy with the RFM22 and I'm glad others are using them too.

Best Regards,
Paul

[lyoung298]

The datasheet for the RFM22 reads sensitivity of -121dBm. So line of sight range of 3000ft should be possible. Similar modules from Linx has a typical receiver sensitivity of -112 dBm. Baud rate also can effect range. Higher baud rates normally decrease range.

[prstein]

The choice of antenna makes a huge difference as well. My RFM22s are 916MHz and I'm using a tiny little antenna (here (http://www.antennafactor.com/products/monopole/jjb-series-monopole-antennas/)). I've only tested to about 30 meters but under awful conditions (through trees and several walls). That was also after setting the transmit power low enough to comply with the U.S. FCC requirements.

Best Regards,
Paul

[leonardodvc]

This is my code:biggrin-new:

'************************************************* ***************
'* Name : TRANSPONDEDOR.BAS *
'* Author : Leonardo Castillo *
'* Notice : Copyright (c) 2011 [select VIEW...EDITOR OPTIONS] *
'* : All Rights Reserved *
'* Date : 26/12/2011 *
'* Version : 2.0 *
'* Notes :programa terminado pero aun no probado fisicamente *
'* :se le adecuo un display para poder probarlo *
'************************************************* ***************
include "modedefs.bas"
'Device 16F627
'Config WDT_OFF, PWRTE_ON
DEFINE OSC 4
DATO VAR Word
DATO2 VAR word
RGIT VAR byte
I VAR Byte
Boton1 var byte
Bandera var byte
ChkSum var byte
Symbol SDO=PORTA.0 'SDO , en el microcontrolador se configura como entrada
Symbol SDI=PORTA.1 'SDI , en el microcontrolador se configura como salida
Symbol SCK=PORTA.2 'SCK , en el microcontrolador se configura como salida
Symbol nSEL=PORTA.3 'nSEL , en el microcontrolador se configura como salida
Symbol nIRQ=PORTB.0 'nIRQ , en el microcontrolador se configura como entrada
symbol Boton=PORTB.2 'Boton de seleccion
goto inicio
Configs:
nSEL = 0
ShiftOut SDi,SCK,msbfirst,[DATO\16]
nSEL = 1
asm ;pauseus 10
nop
nop
nop
nop
nop
nop
nop
nop
nop
nop
endasm
Return
Inicio:
CMCON=7
'76543210
PORTA = %00000001
PORTB = %00000101
boton1=0
Pulsar:
pause 200
if boton=1 then pulsar
boton1=boton1+1
pause 1000
if boton=0 then boton1=boton1+1
Esperadejapulsar:
if boton=0 then esperadejapulsar
'Inicializa dispositivo transpondedor
PAUSE 500
DATO = $8038 : GoSub CONFIGS 'habilita registros, 915Mhz, 12.5pF
if boton1=1 then
DATO = $8208 : GoSub CONFIGS 'activas cristal oscilador, !PA
elseif boton1=2 then
DATo = $82D8 : GoSub CONFIGS 'activa cristal, !PA, habilita resepcion
endif
DATO = $a640 : GoSub CONFIGS 'frec centrada en 912 MHz
DATO = $c647 : GoSub CONFIGS 'velocidad de datos 4789 Kbps
DATO = $94a0 : GoSub CONFIGS 'VDI, FAST, 134kHz, 0dBm, -103dBm
DATO = $c2ac : GoSub CONFIGS 'modo de recuperacion de reloj auto, velocidad de recuperacion de reloj lenta, filtro de datos digital, nivel de calidad de datos (Threshold) 4
DATO = $ca80 : GoSub CONFIGS 'nivel FIFO 8, longitud de sincronizacion 2 bytes, fifo fill inicio de sincronizacion, sensivilidad de reset alta
DATO = $ca83 : GoSub CONFIGS 'FIFO8, sync (sensivilida de reset fifo lenta y habilita fifo fill
DATO = $c49b : GoSub CONFIGS 'habilita afc, strobe, habilita registro de frecuencia offset (registro offset 15 a -16 ) solo mientras vdi=high
DATO = $9850 : GoSub CONFIGS '!mp, 9810=30kHz, MAX OUT post frec shift, 90 KHz deviation and power out 0 db -txt control command
DATO = $e000 : GoSub CONFIGS 'comando wake up timer no usado
DATO = $c800 : GoSub CONFIGS 'comando low duty-cycle no usado
DATO = $c000 : GoSub CONFIGS '1.0Mhz, 2.2v
if boton1=1 then
gosub transmicion
else
gosub resepcion
endif
boton1=0
goto Pulsar
Transmicion:
if boton=1 then transmicion 'espera a iniciar el envio de datos
DATO = $8228 : GoSub CONFIGS 'activa cristal oscilador, habre PA
@ nop ;retardo de 4 us 1 instruccion = 1 us a 4 Mhz
@ nop
@ nop
@ nop
DATo = $8238 : GoSub CONFIGS 'activa cristal, habilita transmicion
@ nop ;retardo de 2 us
@ nop
loop1:
if nirq = 0 then
ChkSum=0
i=0
repeat
' lookup2 i,[$AA,$AA,$AA,$2D,$D4,"LeonardoCastillo",ChkSum,$AA,$55],dato2 'de esta forma en una sola linea se pone todo el formato pero consume mas bytes de memoria
lookup i,[$AA,$AA,$AA,$2D,$D4,"LeonardoCastillo",$55],dato2
if dato2<>$AA or dato2<>$55 then ChkSum=(ChkSum+16)&$FF
if dato2<>$55 then gosub enviar
i=i+1
until dato2=$55
dato2=chksum : gosub enviar'si se usa instruccion lookup2 se elimina esta instruccion
dato2=$AA : gosub enviar 'si se usa instruccion lookup2 se elimina esta instruccion
endif
DATO = $8208 : GoSub CONFIGS 'activa cristal, sierra PA
DATO = $8200 : GoSub CONFIGS 'finaliza resepcion, entra en reposo
pause 1000
GoTo inicio
'siempore que un comando de lectura sea identificado se podra leer el registro
'STATUS a travez del pin SDO y embiando los pulsos de reloj requeridos
'Como solo nos interesa leer el bit RGIT (FIN DE TRANSMICION) que corresponde al
'bit 16 del registrto y como siempre el primer bit en salir es el 16, solo se
'requiere de un pulso de reloj, para poder leer dicho registro, el pin SDI debe
'ponerse a nivel bajo (SDI=0)

Enviar:
RGIT=0
dato=DATo2|$B800 'se suma al comando de lectura (OxB800 el byte de la letra o dato enviado
Loop2:
SCK=0 'baja señal de reloj
nSEL=0 'baja señal y habilita el dispositibo para injiciar la transmicion
SDI=0 'baja señal de dato para habilitar la lectura del registro STATUS
SCK=1 'eleba señal de reloj para iniciar el pulso y obtyener la lectura por el pin SDO
if SDO=1 then 'checa el bit 16 (RGIT) del reg status mediante el pin SDO y que es el
RGIT=1 'que primero se lee y si esta en alto entonces significa que termino la transmicion
else
RGIT=0 'si hay transmicion en progreso(SDO=0), coloca esta otra bandera
endif
SCK=0 'baja señal de reloj para finalizar pulso
SDI=1 'eleva señal de datos
nSEL=1 'deshabilita dispositivo transpòndedor
if RGIT==0 then 'si sigue transmitiendo se vuelbe a habilitar el dispositivo para
goto Loop2 'iniciar la lectura del reg status hasta completar la transmicion
else 'pero si termino de transmitir (se enviaron los 16 bits)
RGIT=0 'el microcontrolador almacena los siguientes byts en el
gosub configs 'transpondedor en forma serial mediante esta rutina
endif
return
' Resepcion empleando interrupcion nIRQ
Resepcion:
if boton=1 then resepcion 'espera a iniciar resepcion
' Define LCD registros y bits
Define LCD_DREG PORTB
Define LCD_DBIT 4
Define LCD_RSREG PORTB
Define LCD_RSBIT 2
Define LCD_EREG PORTB
Define LCD_EBIT 3
Parcial var word
Result var word [25]
BStatus var word
pause 500
i=0 'inicializa contador
nsel=1
sdi=1
sck=0
sdo=0
IniciaResep:
while nIRQ=0 '(!nIRQ)
gosub leeFIFO 'LeeFIFO
result[i]=parcial 'almacena en registros
i=i+1
if i=16 then i=0 : GOTO ESCRIBELCD
DATo = $ca80 : GoSub CONFIGS
DATo = $ca83 : GoSub CONFIGS ' //reset a FIFO y lee el siguiente Byte resibido
wend
goto iniciaresep
LeeFIFO: 'Rutina FIFO
SCK=0;
SDI=0;
nSEL=0;
SHiftIn SDo, SCK, msbpre, [bstatus\16] 'lee y salta bits status, quedan almacenados
SHiftIn SDo, SCK, msbpre, [parcial\8] 'lee y almacena byte de datos del registro FIFO
nSEL=1
RETURN
EscribeLCD:
lcdout $FE,1 'limpia pantalla
Escribe: 'escribe en la pantalla el mensaje almacenado en las variables
for i=0 to 16
LCDOUT result[i]
next i
goto inicio 'regresa al inicio del programa
end

[craigwb]

Hi Paul

I Have bought some RFM22B's and connected up to a 16F883 Pic and connected up as per your setup and code.
Everything seems to be working until I press the TX button It does transmit but, stays in that mode with Led On.
It gets stuck in To_TX_Mode: at the TXWait: Loop, I have read the Serout2 to my Pc too see if the packet is being sent.etc.

I have tried changing address $05 to $02 but, I seem to get stuck here.
Could you Please tell me if you have any suggestions as to why I am getting stuck?

Thanks In advance!

Kind Regard
:)Craig

[prstein]

Hello Craig,

Have you made any changes to the code? Perhaps added an interrupt that might be pulling it out? If you have made some changes please post your code, it might be somewhat easier than guessing...

Just to test something, try replacing

TXWait:
if nirq = 1 then
goto TXWait
endif with "pause 100" or something like that.

Also, check with a meter or scope that nIrq actually goes low.

Best Regards,
Paul

[craigwb]

Hi Paul

Thanks for the reply, I have used the code exactly like you have written it without any extra interupts etc.
What I did was remove the TXWait and just put a PAUSE 100 in then it does transmit.
What is funny is if I put a meter on the nIRQ pin then it keeps sending info on the SEROUT2 and the TX Led remains ON,
If I take the meter off the pin then it settles down ant the TX Led switches off. What I did was wire an extra LED onto a unused pin on the PIC and then
monitor this in relation to the nIRQ pin when it goes High or Low.

I read no voltage on the nIRQ pin but the extra led stays on so there is something weird with this pin?
Maybe I should rebuild the PCB onto a Veraboard instead on leaving it all on a Bread Board as there seems
to be a lot of capacitance floating around, I suppose that this could cause a problem on the nIRQ pin?

What can you suggest Paul?

Kind Regards

:)Craig

[prstein]

Hello Craig,

I suspect you've found the problem--capacitance (or other leakage) in the setup. Good job! I think you'll do better on veraboard... For a quick fix try putting relatively high value pull-down resistors (~10k to 1M) on the nIrq and LED pins. From what you describe something is causing one of those pins to float high.

Best Regards,
Paul

[craigwb]

Thanks Paul

I will rebuild and see how it goes.

Kind Regards

Craig

[camerart]

Hi All,
I've just ordered some similar RFM modules, and hope to get them working. The code above looks good, and thanks.
Camerart.