FromSquonk42 wrote:It looks like RFM69s are just (legal?) repackaged SX1231H chips:
https://lowpowerlab.com/forum/rf-range- ... es-or-not/
Note: Although not documented, the Hope RFM96 actually supports Semtech's Low Data Rate Optimization (supported by Semtech SX1272 and SX1276) so we can use LoRa Mode 1 for maximum range, minimum bandwidth transmission. Refer to Page 28 of Semtech SX1272 Datasheet: http://www.semtech.com/images/datasheet/sx1272.pdf
Low Data Rate Optimization Given the potentially long duration of the packet at high spreading factors the option is given to improve the robustness of the transmission to variations in frequency over the duration of the packet transmission and reception. The bit LowDataRateOptimize increases the robustness of the LoRa link at these low effective data rates, its use is mandated with spreading factors of 11 and 12 at 125 kHz bandwidth.
Hope RFM96 seems to be derived from the Semtech SX1276: http://www.semtech.com/images/datasheet/sx1276.pdf. Although not documented, Hope RFM96 (but not RFM95) supports the Low Data Rate Optimization setting in RegModemConfig3 (register 0x26) exactly the same way as the SX1276. See Page 114 of the SX1276 datasheet. I confirmed this by checking the Hope library code (HoepRF_HSP_V1.0\libraries\HopeRFLib\HopeDuino_LoRa.cpp) at http://www.hoperf.com/demo_tools/419.html