Gonna try and get blood oxygen working. It starts with `StartHeartRateReq.getSimpleReq((byte) 3` It's type `105`, just like the HR measurement, but the type is `3`instead of `1` Huh, I just noticed I had swapped the order of bytes in the initial payload for HR and it still worked? Weird, but I've fixed it for now. The second byte is `BLEDataFormatUtils.decimalToBCD(25)` which is 37 or `0x25`... That seems pretty silly but whatever. And it works! I can get an SPO2 measurement by sending `bytearray(b'i\x03%\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x91')`. I did receive `bytearray(b's\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00v')` but I don't know what that is for. I don't think I have a `0x73` or `115`, although it might have the high bit set and indicate an error... There's a `CMD_DEVICE_NOTIFY` but it's not used anywhere