Standardize on RFM69HW radio?

[JimInWoodstock]

Has anyone played around with using a RFM69HW and then setting the power level down so that it outputs a 13db signal? If that works, then the high power version can always be purchased and, if you need more battery savings on transmit, just dial the power down. And, of course, if you need the extra power, crank up the power level.

[Felix]

I guess it's just a matter of preference. I offer both in the shop so people that don't really need more than 13dBm (which is quite a bit of power!) can just use that and not mess with the power settings.  At the moment both kinds are pretty popular with HW leading the way a little.

[TomWS]

Has anyone played around with using a RFM69HW and then setting the power level down so that it outputs a 13db signal? If that works, then the high power version can always be purchased and, if you need more battery savings on transmit, just dial the power down. And, of course, if you need the extra power, crank up the power level.

Jim, I use this all the time.  Check out the library I reference in https://lowpowerlab.com/forum/index.php/topic,966.msg6195.html#msg6195.  This library is set up to automatically set the transmit level so that a reliable but not overpowered signal is received at the far end.  You just initialize a 'targetRSSI' on your sender and, as long as the far end also implements the library, the sender will receive Acks from the far end and adjust the transmit level from 13db up -2dBm to the max of +20dBm on an HW radio.  Monitoring the transmit level on my motes, most of them are running at minimum power output...  And those that aren't don't need the level boosted to max, they've just tweaked their power to achieve a reliable signal.

Tom
UPDATED: 3/31/15 to correct power output range of RFM69HW.

[KanyonKris]

Remember that the low end of the power range is also different. The RFM69W can go down to -18dBm, the RFM69HW can only go down to -2dBm. For projects where the Moteinos are near each other and low power is very important (i.e. battery powered), being able to choose lower power output may be important.

https://lowpowerlab.com/forum/index.php/topic,362.msg2129.html#msg2129

[TomWS]

<...snip> the RFM69HW can only go down to -2dBm. <snip...>

Good point. Yes, you are correct.  I misstated the power range, for the RFM69HW it is -2dBm to +20dBm.  I'll correct my post.

BTW, the ATC code works equally well for the W version (albeit at lower power).

Tom