RN52 line-in gain command SL,<32 bit hex value>. Firmware v1.16
Does anyone have information on using the command to set the line in gain, SL,<32 bit hex value>? This command is not listed in the latest Bluetooth Audio Module Command Reference User’s Guide DS50002154A but is listed when the H command (Help) is sent to the RN52. The microphone gain command SM,<32 bit value> is in the format <resresMBMA> where MA is the gain of microphone A and MB is the gain of microphone B, but I don’t believe that SL uses the same format. When I get the default data for the microphone gain, by sending GM, 00000909 is returned, which fits the format described in the Command Reference but when I send GL, 60906090 is returned, so the data format is obviously different. Experimenting has shown me that 6090 is not just the gain for one channel because setting SL to 5080 results in negligible difference to the volume level transmitted by the module but setting SL to 6080 results in a noticeably quieter signal. Can anyone tell me what each bit in the 32 bit hex value used with SL does?
Also, I am assuming that line-in or microphone input is selected by setting the gain for the input mode required as I can’t find any other command to select the input type. Can anyone confirm this?