Apologies for the very very basic question but I’ve just bought a RFM69Pi (868 Mhz) and hopefully connected it to the right ports on my Raspberry Pi 2. (There wasn’t anything on the wiki on which ports to use so I just located it via some of the images on the wiki).
I managed to disable the ttyAMA0 serial port using the raspi-config and ran the minicom -b38400 -D/dev/ttyAMA0 command. Should I be expecting something back from the minicom (should it display anything) or should it say connected, as it currently says disconnected.
Basically is there any way to determine I’ve connected everything up and the RFM69Pi is working correctly?
If you use minicom to send a ? character you should get a list of commands returned. The rfm**pi’s do print a message at start up but that is way too early for the Pi to have loaded the OS and receive it.
Just onfirm the board sits on the end 10 pins nearest to a corner of the Pi and the rfm board should not overhang the edges ie the over hang points towards the centre of the Pi.
Amazing. Thank you. It displayed:
<nn> i - set node ID (standard node ids are 1..30)
<n> b - set MHz band (4 = 433, 8 = 868, 9 = 915)
<nnnn> o - change frequency offset within the band (default 1600)
96..3903 is the range supported by the RFM12B
<nnn> g - set network group (RFM12 only allows 212, 0 = any)
<n> c - set collect mode (advanced, normally 0)
t - broadcast max-size test packet, request ack
...,<nn> a - send data packet to node <nn>, request ack
...,<nn> s - send data packet to node <nn>, no ack
<n> q - set quiet mode (1 = don't report bad packets)
<n> x - set reporting format (0: decimal, 1: hex, 2: hex+ascii)
123 z - total power down, needs a reset to start up again
Remote control commands:
<hchi>,<hclo>,<addr>,<cmd> f - FS20 command (868 MHz)
<addr>,<dev>,<on> k - KAKU command (433 MHz)
O i15 g210 @ 433 MHz q1
I’m assuming the last line means even though I bought a 868Mhz model it is running at 433MHz.I changed it to via 8b.
Hopefully it will stick that way from now on.
Last question on this. (So sorry to bother, but I’m starting my knowledge from scratch).
I now seem to have it working on 868Mhz, but I haven’t really got a clue what Node Id, etc the sending device is transmitting on.
I’m hoping to receive 868Mhz data from the water meter outside my house (in the middle of the pavement). All the documentation says the water meter will be transmitting on 868Mhz. Is there a way to set the RFM69Pi to display all data it receives, or is this just normally functionality.
Obviously I’ve tried sitting right next to the meter but nothing is appearing on minicom. I’m just hoping I don’t have to pass a sending token for it to start transmitting something back!
Unfortunately it’s not likely to be as easy as that. Although it may share the same frequency band there are many different transmission types, protocols, formats, handshakes etc etc. It may not be overly difficult but it is unlikely to work “out of the box”.
You could try unsetting “quiet mode” using the “0q” command to see if there is any “discarded packets”, if there are that may mean there are transmissions about that do not fit the “JeeLib” protocol exactly and are assumed to be garbage, if there is some “garbage” that can be “traced” to the water meter location by moving the receiver around then that may suggest the water meters transmissions are of a type that might be able to be collected with the rfm2pi with some different firmware.
But none of this is conclusive, a better approach maybe to do some searching on the meter model to see if anyone else has “hacked” one and work from there.
Even knowing what data is transmitted, when and in what format would help locate and decipher any potential packets seen by the rfm2pi.
Unrelated sidenote - I noticed the last comment had been liked by “someone” when I first read it, curious as to who that was, I took a look and was quite surprised to find it was me - apparently, I had not knowingly liked the post (not that I have anything against it either) so I’m unsure how that happened !! but I have now learnt that a like cannot be undone - one to watch out for!!
I’m largely guessing here, but my thoughts are: The water meter needs power from somewhere - where it gets its power is a big clue. It might be inductively powered from the meter reader, or from some incoming r.f. (like an RFID chip) or battery powered, or maybe it has a small generator that uses the water flow, but either way power will be strictly limited. So I would expect the meter to never transmit until asked. And although it sits receiving, it probably only switches on for a few ms every second or so to listen for a basic ‘wake up’ command.
As Paul says, your best bet is you’re not the first, and the first has published something.