Concept2 Forum

You didn't say how you were "reading" the characteristic. Bluetooth is so slow that issuing a "characteristic read" and waiting for a response may well not work consistently. All of the interesting values (including heartrate) are broadcast (Bluetooth calls it "notify") and all can be turned on duri...

Here's the deal. The PM expects an HID format request and provides an HID format response. You show no sign of sending this format - the "09" is a report ID, and controls the allowed USB frame length. "09" is 0x80 + 0x01. The 0x80 indicates an error, and the 0x01 says that the PM is expecting a 20 b...