The following is the packet forwarder logging an uplink.
JSON up: {"rxpk":[{"tmst":3373830419,"chan":3,"rfch":0,"freq":904.500000,"stat":1,"modu":"LORA","datr":"SF7BW125","codr":"4/5","lsnr":10.0,"rssi":-39,"size":28,"data":"QAoKCgAAJQABfxVMDm6JF8vfuGk+4eC+yWA+wQ=="}]}
CS then invokes a response downlink, which is picked up and logged by the packet forwarder. Showing frequency 925.1 , spread factor 9 and bandwidth 500 kHz , coding rate 4/5.
If a payload were enqueued, it would appear appended to “data”
JSON down: {"txpk":{"imme":false,"rfch":0,"powe":20,"ant":0,"brd":0,"tmst":3374830419,"freq":925.1,"modu":"LORA","datr":"SF9BW500","codr":"4/5","ipol":true,"size":27,"data":"YAoKCgCP6EUDAAEAcAMwAP8BBQho4oyCHma+"}}
My US902 American devices absolutely cannot see this downlink even when they match the frequency immediately after send. Even when they switch to SF9 and BW500. My code is armed to report any errors. I have disabled CRC. My hardware and interrupts are functional as the end devices have communicated many times in the past. But for these gateway downlinks they see nothing arrive over the air.
I suspect the problem is the SF9BW500. Is there a config file where I could change the data rate SF and BW to something else?