RFM12Pi vs RFM69Pi differences and implications

I only purchased the Emon kit from the shop about a month ago and I am wondering what the differences and implications of the differences between the RFM12Pi vs RFM69Pi will be for someone like me.

I gather the change occurred because of supply issues with the RFM12Pi, is that correct?

What about interoperability between a emonBase with one and RPi with the other?

Also note the shop is still stating in the product description detail the information on the that the RFM12Pi, while the component options lists the RFM69Pi.

pb66's picture

Re: RFM12Pi vs RFM69Pi differences and implications

The RFM12 was believed to be "end of life" but as it turns out hopeRF is continuing production but only supplying in large quantities (thousands) so it will undoubtedly be around for a while yet. 

The RFM69 was identified as a replacement and is both compatible with the RFM12 (when run in compatibility mode) as well as having the same physical footprint.

In compatibly mode the RFM69 doesn't offer OOT OOK but is rarely used on the RFM12 so not a huge loss, it does bring a new RSSI feature that allows you to monitor received signal strength though and the reception is reported to be improved a bit.

Since the RFM12 will undoubtedly disappear long before the RFM69 it makes sense for manufacturers to make a switch sooner rather than later, especially as the RFM69 costs the same and will become more readily available, it's expected to become the new "standard RFM".

There are also other features with the RFM69 such as encryption that are not yet utilised due to running RFM12 compatibility mode. development of RFM69 only features will begin to emerge but it will be a considerable time before they become mainstream as there is a large RFM12 following, But by supplying the RFM69 in place of the RFM12 now when the "RFM69 only" features and the demand for them arrives more users will already be using RFM69 and it will be easier to incorperate any "change". 

I can't see support for RFM12 ever stopping and even if the bulk of the network moves over to RFM69 down the line I would expect RFM12 hardware to still be used or even re-purposed for lighter less secure tasks as tech advances.

As for the RFM69Pi that is the Raspberry Pi add-on board that fits directly to the Pi's GPIO connector and has an arduino type processor, a RFM69 transceiver and all the IO from the processor is broken out to a connector for easy connection, It is an improvement on the previous board if you intend to utilise the additional  IO. The previous board originally came with the RFM12 and was changed last year to a RFM69, any other changes are minimal to retain compatibility.

The previous board gets called both RFM2Pi and RFM12Pi, I tend to use the more general RFM2Pi (as in it connects a RFM to a Pi) as it could be a RFM12Pi with a RFM69 fitted, either way they are all compatible** (and pretty much the same) unless you have the need for the extra IO or currently unsupported "RFM69 only" functions. The RFM12 options will disappear from the shop as the products get changed over, aside from using a different JeeLib driver (defined in the sketch) and gaining a RSSI the changes should be fairly transparent. 

emonHub handles both and is able to run multiple RFM networks so if you do have RFM12 devices but also want to expand into "full RFM69" when it comes you can just add another network if push comes to shove and they cannot share rather than replacing older nodes or missing out on newer stuff.

I hope this helps, I'm sure you are not the only one wondering the same.

Paul

** when I say all I'm excluding the RFM2Pi v1 as this had a different processor and is considered less reliable than the current arrangement, so "all" is RFM2Pi v2 onwards.

glyn.hudson's picture

Re: RFM12Pi vs RFM69Pi differences and implications

From the end-users perspective there should be no difference between RFM12Pi V2 and RFM69Pi V3 apart from a new reading (RSSI) appearing in emoncms. The RFM69Pi is fully backwards compatible with RFM12B

craigfryer's picture

Re: RFM12Pi vs RFM69Pi differences and implications

Thanks for the info Paul.

"In compatibly mode the RFM69 doesn't offer OOT"

My Google skills are letting me down. I assume this is a protocol, but I can't any thing about it. Do you mean OOK?

The RSSI information will be very handy.

pb66's picture

Re: RFM12Pi vs RFM69Pi differences and implications

I did indeed mean OOK, not sure where OOT came from :-)

Heliox's picture

Re: RFM12Pi vs RFM69Pi differences and implications

Can anyone say something about the Current consumption of the RFM69Pi Board? I read this http://openenergymonitor.org/emon/buildingblocks/rfm69cw and as far as I know, it's not a good idea to have a Current consumption more than 2-4mA per pin. But I see a Current consumption up to 45mA for the RFM69CW wireless module. So how is this realized in the new board?

 

I am thinking about to use the RFM69CW modules for my new project, but I'm not sure if it's the right module. Another problem is with how much power does the RFM69CW transmit data, because here in Germany there is a limit of 10mW for 433MHz modules?

 

Thanks.

pb66's picture

Re: RFM12Pi vs RFM69Pi differences and implications

Glyn has just written this blog on the rfm69 power consumption 

http://openenergymonitor.blogspot.co.uk/2015/02/rfm69cw-power-consumption.html

And here is a link to the discussion http://openenergymonitor.org/emon/node/10210

A couple of points to consider are that the power for the rfm69 on an rfm69pi (or rfm2pi) comes from the RPi's gpio, This can supply 15mA per pin up to 50mA total on the 3v rail (working from memory, and that was the B, the B+ or 2B have better supplies so may of improved) this will be a constant rating which is plenty. The momentary peak demand of 45mA will be "smoothed" by an on-board capacitor.

I'm not sure where the 2-4mA comes from, maybe you are thinking of the AVR, but that doesn't "supply" the rfm power. The rfm69 is used on several devices I would be very surprised if it doesn't conform to a European regulation but don't have a datasheet to check.

Paul

Heliox's picture

Re: RFM12Pi vs RFM69Pi differences and implications

Thank you for the reply and information! Well I am thinking about to get a RFM69Pi 433MHz Receiver Board, but all of the transmitters will be RFM12B Modules. Can you please tell me if you expect any problems. Is the pre-loaded firmware in compatibility mode and capable of receiving data from RFM12B modules? Thanks.

 

Edit - duplicate post deleted - BT

emjay's picture

Re: RFM12Pi vs RFM69Pi differences and implications

@Heliox,

here in Germany there is a limit of 10mW for 433MHz modules

These regulations refer to the power output by the antenna.  The default configuration for the RFM69 transmitter puts the power output at the maximum setting of +13dBm.  Allowing for losses in the on board antenna matching circuit and that the antenna will not be a perfect radiator reduces the actual radiated power by at least 3dBm, so the radiated power is less than +10dBm.

+10dBm  = 10 mW

Meets the ISM requirements by design and configuration.....

 

 

Heliox's picture

Re: RFM12Pi vs RFM69Pi differences and implications

@emjay

ok, thank you for this information. That's the important thing I wanted to know. :-)

Do you have any experience with a RFM69CW receiver and RFM12B transmitters?

 

Thanks.

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