LoRa Feather M0 short range

[tock]

Hello,

I recently purchased two Adafruit M0 Lora boards, and I soldered on quarter wave antennas, 3 inches each. I was observing dropped packets 3ft away. I am using the standard code provided in the learn example and the RadioHead library.

I found that the receiving board had an RSSI of -100 coming from the sending board whereas the sending board had an RSSI of -22 coming from the receiving board. Changing the mode of the boards resulted in the same situation. The board that originally had an RSSI of -22 now had an RSSI of -100.

I used the uFL connectors with the Lora antenna kit and set the transmission power to maximum but I was barely able to get it to communicate above 300ft, I also set the rf95.setTxPower(23), but this did not change the range.

Am I doing something wrong or was I too optimistic about the ranges that Lora can hit?

[adafruit_support_mike]

Radio transmission depends heavily on the environment, but we've gotten 1km under line-of-sight conditions.

Post a photo showing your hardware and connections and we'll take a look. 800x600 images usually work best.

[tock]

Okay.

IMG_20171017_093654.jpg (279.38 KiB) Viewed 505 times

Would half wave antennas work better? I found that using the duck antenna resulted in a loss of 50% distance to about 150m. This was done with an feather set up at one end of the quiet street and walking down the length.

[adafruit_support_mike]

You might be running into a problem with different antenna types, and possibly antenna orientation.

Every antenna has an emission pattern that's easiest to pick up with an identical antenna. Taking the quarter-wave wire antenna as an example since it's easy to make and the signal is heavily polarized, you can go from maximum signal strength to practically no signal just by turning the receiver's antenna perpendicular to the transmitter's antenna.

Ducks use a helical antenna with an emission pattern that's easier for another helical antenna to pick up if it isn't parallel, but the signal drops to almost nothing if the sender and receiver have antennas wound in opposite directions. A quarter-wave wire antenna won't pick up much signal from a duck because the two antenna shapes don't resonate especially well with each other.

Try matching the antenna type and orientation and see how that works.