This driver is based on sx1280 library which can be found here
Here are the data rates achieved with this library. Notice how the data rate changes based on the payload size
The data rate is linearly dependent on the payload size, which indicates that LoRa always transmits 256 bytes regardless of the configured payload size. After 239 bytes, a drop occurs — likely caused by a buffer overflow in LoRa (since additional data is transmitted alongside the payload). Assuming the payload is always 256 bytes, the theoretical data rate in practice is approximately 204 kbps (the manufacturer specifies 203 kbps under these settings)
Data Rate Table [bps] for a 100-byte payload:
SF5 SF6 SF7 SF8 SF9 SF10 SF11 SF12
Bandwidth
BW_0200 20008.298828 13333.110352 7272.661621 4444.419922 2499.992188 1379.307983 629.920776 349.344849
BW_0400 39998.019531 26665.787109 13333.113281 8888.791016 4999.969238 2758.611328 1249.998047 695.651550
BW_0800 79992.085938 39998.019531 26665.787109 15999.682617 8898.678711 5333.297852 2499.992188 1379.307983
BW_1600 79992.085938 79992.085938 39998.019531 26665.787109 15999.682617 9999.875977 4999.969238 2758.611328
Data Rate Table [bps] for a 200-byte payload:
SF5 SF6 SF7 SF8 SF9 SF10 SF11 SF12
Bandwidth
BW_0200 22862.560547 13333.221680 7999.960449 4705.868652 2666.662354 1467.888550 669.455811 371.229614
BW_0400 39999.007812 26666.226562 15999.841797 9411.709961 5333.315918 2909.085693 1333.332275 740.740417
BW_0800 79996.039062 53331.574219 31999.365234 17777.582031 10006.192383 5714.265625 2666.662354 1481.480103
BW_1600 159984.171875 79996.039062 53331.574219 31999.365234 19999.751953 11428.490234 5333.315918 2962.957520
Data Rate Table [bps] for a 229-byte payload:
SF5 SF6 SF7 SF8 SF9 SF10 SF11 SF12
Bandwidth
BW_0200 22947.558594 14091.223633 8326.894531 4697.315430 2694.078125 1489.418701 676.012268 374.641357
BW_0400 45788.554688 26167.689453 16653.031250 9159.542969 5388.076660 2954.791016 1347.048950 747.752075
BW_0800 91554.218750 45788.554688 30528.246094 18318.167969 10177.212891 5909.486816 2694.078125 1489.418701
BW_1600 183009.671875 91554.218750 61046.316406 36632.671875 20353.294922 11449.284180 5388.076660 2954.791016
Data Rate Table [bps] for a 230-byte payload:
SF5 SF6 SF7 SF8 SF9 SF10 SF11 SF12
Bandwidth
BW_0200 23047.767578 14152.757812 8363.256836 4717.827637 2666.628174 1483.859009 676.468079 374.744629
BW_0400 45988.503906 26281.958984 16725.751953 9199.540039 5256.992676 2967.694092 1352.931274 747.964478
BW_0800 91954.023438 45988.503906 30661.556641 18398.160156 10221.654297 5935.292480 2705.842529 1495.922729
BW_1600 96791.164062 91954.023438 61312.894531 36792.640625 20442.173828 11499.281250 5411.605469 2967.694092