Description
When the frequency is passed in to init it is incorrectly stored as
self.frequency
https://github.com/adafruit/Adafruit_CircuitPython_RFM69/blob/master/adafruit_rfm69.py#L343
but the actual "setter" is
self.frequnecy_mhz
https://github.com/adafruit/Adafruit_CircuitPython_RFM69/blob/master/adafruit_rfm69.py#L536
So that new frequency is not actually sent to the chip.
This is a similar issue found in the rfm9x driver and fixed there via adafruit/Adafruit_CircuitPython_RFM9x#4 . There were a few additional issues found in that may also be appropriate for this driver.
Posted in response to Forum post https://forums.adafruit.com/viewtopic.php?f=8&t=135989&p=674098#p674098
The default setting of 915 Mhz is in section 6.2 table 24 of the data sheet https://cdn-shop.adafruit.com/product-files/3076/RFM69HCW-V1.1.pdf
whereas the RFM9x defaults to 433Mhz - see section 6.1 table 85
https://cdn-learn.adafruit.com/assets/assets/000/031/659/original/RFM95_96_97_98W.pdf?1460518717