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434 MHz ASK/OOK AM transmitter/receiver
http://jap.hu/electronic/rf/rx3304.pdf
The opamp part of the circuit above is something I tried to
decode the Arssi (RFM12B) signal,for the location off this signal
see http://blog.strobotics.com.au/2008/06/17/rfm12-tutorial-part2.
The RF receive Range off RFM12B arrsi + opamp is the same ,compared to other
receivers,aldo there is not much filtering on the circuit (2.5khz)
so I think it can be better.
The first opamp circuit is not well suited
for the RFM12B .
GAIN is much to high, and bias has to be removed
from input.
Here is a the first opamp ,with minimal
components (4).
basic single stage amplifier Non-inverting amplifier.
\5spice\FILTER LM356324.Sch
netlist
RFM12B C1.2, => input
C1.1, U1.3, R1.2,
R1.1, Ground, R3.1,U1.4,
U1.2, R3.2, R2.1,
U1 8 3.3v
R2.2 ,U1.1, => output
C1 = 1 uF R3 =560
R1 = 120k R2 =22k
This circuit can be improved ,but it gives good result.
Congrats on getting OOK reception with the ARRSI signal. Did you get this working with the OOK receiver sketches ?
Hello andras,I use ds20demo.pde as a sender
with this settings in RF12.cpp
rf12xfer(0x80C7 | (band << 4)); // EL,EF,12.0pF
rf12xfer(0x8209); // enable xtal, disable clk pin
rf12xfer(0xA68a); // (0xa68a FS20 868.250) 90khz )
rf12xfer(0xC606); // 57.6Kbps (38.4: 8, 19.2: 11, 9.6: 23, 4.8: 47)
rf12xfer(0x94A0); // VDI,FAST,134kHz,0dBm,-103dBm
rf12xfer(0xC2AC); // AL,!ml,DIG,DQD4
rf12xfer(0xCA83); // FIFO8,SYNC,!ff,DR
rf12xfer(0xCE00 | group); // SYNC=2DXX?
rf12xfer(0xC483); // @PWR,NO RSTRIC,!st,!fi,OE,EN
rf12xfer(0x9850); // !mp,90kHz Devation Frequenzabstand des High- und Low-Wertes bei der Ubertragung im FSK-Betrieb,MAX OUT
rf12xfer(0xCC77); // OB1?OB0, LPX,?ddy?DDIT?BW0
rf12xfer(0xE000); // NOT USE
rf12xfer(0xC800); // NOT USE
rf12xfer(0xC040); // 1.66MHz,2.2V
I use this file (http://jeefiles.equi4.com/recv868fs20.pde )as a receiver with
some software of the raw wiki Raw RF12 transmit demo, the RF12 init values are changed !!
// RFM 12B functies
static void rf12enable () {
PORTSPI &= ~ BV(DDSS);
}
static void rf12disable () {
PORTSPI |= BV(DDSS);
}
static void spiinit () {
rf12disable();
DDRSPI |= BV(DDMOSI) | BV(DDSCK) | BV(DDSS);
DDRSPI &= ~ BV(DDMISO);
SPCR = BV(SPE) | BV(MSTR) | BV(SPR0);
SPSR |= BV(SPI2X);
}
static uint8t rf12byte (uint8t out) {
SPDR = out;
loopuntilbitisset(SPSR, SPIF);
return SPDR;
}
static uint16t rf12xfer (uint16t cmd) {
rf12enable();
uint8t r1 = rf12byte(cmd >> 8);
uint8t r2 = rf12byte(cmd);
rf12disable();
return (r1 << 8) | r2;
}
static void rf12init () {
rf12xfer(0x8028); // EL,EF,12.0pF
rf12xfer(0x82c0); // enable xtal, disable clk pin
rf12xfer(0xa67e); // 868.2500 MHz 0xa688
rf12xfer(0xC606); // 57.6Kbps (38.4: 8, 19.2: 11, 9.6: 23, 4.8: 47)
rf12xfer(0x90d8); // VDI,FAST,134kHz,0dBm,-103dBm // 90d8 no noise
rf12xfer(0xC26C); // AL,!ml,DIG,DQD4
rf12xfer(0xCA80); // FIFO8,SYNC,!ff,DR
rf12xfer(0xCE00 | GROUP); // SYNC=2DXX?
rf12xfer(0xC4F6); // @PWR,NO RSTRIC,!st,!fi,OE,EN
rf12xfer(0x9850); // !mp,90kHz,MAX OUT
rf12xfer(0xCC77); // OB1?OB0, LPX,?ddy?DDIT?BW0
rf12xfer(0xB800); // NOT USE
rf12xfer(0xC800); // NOT USE
rf12xfer(0xC040); // 1.66MHz,2.2V
}
static void rf12send (uint8t out) {
while ((rf12xfer(RFSTATUS) & RFREADY) == 0)
;
rf12xfer(RFXMITREG | out);
rf12crc = crc16update(rf12crc, out);
}
This better circuit use an amplifier and a comparator , to make the interrupt signal
Netlist
Exported from OOKACcoupledinvertingamplifier.sch at 1/23/2010 5:34:53 PM
EAGLE Version 5.6.0 Copyright (c) 1988-2009 CadSoft
Net Part Pad Pin Sheet
N$1 C1 2 2 1
R1 1 1 1
N$2 C2 1 1 1
IC1 2 -IN 1
R1 2 2 1
R2 1 1 1
N$4 C2 2 2 1
IC1 1 OUT 1
IC1 5 +IN 1
R2 2 2 1
N$5 C3 1 1 1
IC1 3 +IN 1
IC1 6 -IN 1
R3 1 1 1
R4 2 2 1
N$6 IC1 7 OUT 1 // output SV1 AI0 Jeenode PORT1
SV1 2 2 1
N$8 C1 1 1 1
JP1 1 1 1 // input from RFM12B ARSSI
N$15 C3 2 2 1
C4 - - 1
C5 2 2 1
IC1 4 V- 1
R4 1 1 1
SV1 4 4 1 // SV1 GND Jeenode PORT1
N$16 C4 + + 1
C5 1 1 1
IC1 8 V+ 1
R3 2 2 1
SV1 3 3 1 // SV1 3.3V Jeenode PORT1
Part Value Device Package Library Sheet
C1 10nF C-EUC2012 C2012 rcl 1
C2 33p C-EUC2012 C2012 rcl 1
C3 100nf C-EUC2012 C2012 rcl 1
C4 10uF CPOL-EUE2,5-6E E2,5-6E resistor 1
C5 100n C-EU025-025X050 C025-025X050 resistor 1
IC1 LM358 LM358N DIL08 linear 1
or
IC1 TCL27M2 see notes
JP1 PINHD-1X1 1X01 pinhead 1
R1 22k R-EUM2012 M2012 resistor 1
R2 1M5 R-EUM2012 M2012 resistor 1
R3 56k R-EUM2012 M2012 resistor 1
R4 27k R-EUM2012 M2012 resistor 1
SV1 MA06-1 MA06-1 con-lstb 1
REMARKS
R4 = 39k when using TLC27M2
R4 = 27k when using LM358 // don't use pull-up on int = digitalWrite(RXDATA, 0) LM358 can't pull it to zero;
R2 can be 470k-1M5 1M5 can be to sensitive for codes send within 2 meters .
FSK will not work with these changed RF12 init values,but you can send and receive OOK with these wonderful jeenodes.
Joop, if you email me the files I can place them on the wiki so they don't get messed up as with this forum software.
Yes,I will send the files .
Joop, you mentioned that the RF12 config values need to be different - is there a way to use settings which still work with FSK as well? Then we could have the best of both worlds: simultaneous OOK & FSK use.
Yes, I think that's possible, I changed this values because I use different transmit
and receive software to demonstrate it works.
It would be nice to have an option ,to input the exact send/receive frequentie of
the OOK device in the config menu,because they differ in the various OOK modules.
(0xa68a 868.250) ),then you can keep the FSK frequentie
the same.( or you have to switch between freqeunties this is , maybe also possible but you still have differrent OOK module frequenties)
I don't have the knowledge off the RFM12 to do this,I also changed rf12xfer(0x9320)
but maybe this can be the same as the in the RF12.zip.
I will send the Eagle and 5spice files.
Description is on the wiki . http://wiki.jeelabs.net/p/85 RFM12B OOK-receiver.