I have two Moteinos at either end of my desk i.e. about 3 feet apart.
The Tx and Rx RFM69HW 898MHz is set on high power to use 15dBm, both use a SMA connector to an external (to the case) aerial RS part number 542-563
The Rx is reporting -54 on its RSSI.
Is this correct that so much signal is lost over such a short distance?
-54 is a bit low.
Make sure you program the IS_RFM69HW parameter correctly and match the frequency band, and antennas are attacheds.
As mentioned in my original post I do call radio.setHighPower(true)
The aerials are 868MHz types and connected to the board via SMA and 50 ohm coax.
Initially I was not calling the setHighPower function, have I blown up my boards?
I don't think there's a proven way to blow them up. We have discussed some theories in this forum about what might damage them. Running with a very mismatched load (no antenna for instance) causes the output to reflect back into the source (the transceiver) which heats it up. That is a known fact of physics. Does that heat up the chip enough if run for a long enough time to damage it? Perhaps. The chip has very little capacity to cool itself down, only the GND pad is there to dissipate heat. The internals could be sensitive to such reflections but again ... not a proven way to damage them. I have done this many times and the chips were fine afterwards. Not trying to imply anything, but there are many other ways to damage chips also.
I think it will be more obvious if something is wrong when you take them apart and use the standard lib settings and everything is set correctly. If you get dismal range, something might be wrong yes. But do you get the same result from all your Moteinos? Did you treat the identically? Can we narrow down to the ones you think you "blew up"?
I only have 2 Moteinos :(
I will double check everything again.
You can review my code here:
https://github.com/steveww/sensors
https://github.com/steveww/Gateway
FOUND IT!
The SMA pig tail I have on my tx board, the bulkhead connector is just too short or the box wall too thick, depending on how you want to look at it, for the aerial to fully connect. Thus there was some stray resistance/capacitance going on in there and no doubt reflecting the signal. A little countersinking on the inside of the case provides enough clearance.