iOS 11.2.1, External accessory not writing data to MFi device via Lightning connector,
After checking ATS log provided by apple, iPhone is sending bad packet to the hardware only when connected with USB lightning cable. It works perfectly for BT connection.
We have verified the NSOutputStream write: maxLength: api returns success(0) for all write operation. Also, logged the actual bytes information. From application side everything is working. But, When we check with ATS log iPhone USB stack is sending bad packet with 000...... bytes.
This issue is identified from iOS 11.2.1.