I believe I have a 433MHz EmonTx V3 and a 433MHz RFM12B board for Pi. With the supplied OEM Gateway Pi firmware, after having updated the conf file, when powering up the pi the green led on the RFM12B flashes once and then nothing.
So I installed a fresh version of Raspian on my Pi disabled the serial port, installed and ran minicom and plugged in the RFM12B (the EmonTx is on and flashing every 10 seconds, with CT1 sensing current). I get nothing in the minicom window and the RFM12B doesn't appear to be responding to my attempts to change its configuration.
This may all be down to my lack of experience with minicom. Having fired it up using:
$ minicom -b9600 -D/dev/ttyAMA0
and then plugging in the RFM12B, should I see some output from the RFM12B?
Should I just be able to type commands to configure the RFM12B at this point and what response should I expect, or do I have to configure minicom first? When I type a character the green led illuminates, should i be terminating commands with a <CR>? With or without <CR> appears to make no difference.
Could the lack of RFM12B flashing be due to either the EmonTx or RFM12B not being set to 433MHz as expected?
To determine if the EmonTx is set to the correct frequency do I need to purchase a UART to USB converter from the store?
Cheers, Joe
Re: Basic comms between Raspberry Pi and RFM12B
Have you tried plugging the RFM12Pi board in before powering on the Pi, then when the pi has booted up, log in and run the minicom command.
Whilst you could set the EmonTx or RFM12Pi to something other than 433MHz, the chip is actually different between the different frequencies. So if you purchased 433MHz that is what it will be set to.
Re: Basic comms between Raspberry Pi and RFM12B
With the RFM12Pi board plugged in before power up it is not possible to log on to the Pi, sorry forgot to mention this.
I would have expected that provided that EmonTx and Base station are set to the same frequency that irrespective of the software on the Pi, but provided that the serial port has been disabled to allow an external device to use it, that the RFM12Pi should periodically flash to show data packets being received from the EmonTx (which is flashing every 10 seconds).
I would also have expected to see some data appearing in the minicom window - unless I have not set this up correctly.
What else could be causing what appears to be the base station not hearing the EmonTx's transmissions? Is antenna length another potential point of failure? Perhaps I should measure these this evening. I guess maybe that the EmonTx is only presenting the illusion of transmitting. I think I read somewhere that you can hardwire the EmonTx to the base station. Feels like I need to order the UART to USB adapter to investigate further.
Re: Basic comms between Raspberry Pi and RFM12B
If you can't log on to the pi if the RFM12Pi is attached at powerup you have a problem... You should be able to.
So I think you need to focus your attention on the pi and rather than the emontx end.
(although the UART to USB adapter is a handy thing to have anyway ;-) )
Other than checking you have it plugged into the correct pins, double check that pin 1 on the RFM12Pi connects with Pin 1 on the RasPi. The RFM12Pi should sit as close to the SD card as possible.
If that's OK, I suggest you contact the shops support email address. http://shop.openenergymonitor.com/support/