I am having issues interfacing with the B-L475E-IOT01A's on-board SPBTLE-RF bluetooth chip.
I am able to send header packets inquiring about the the bluetooth chip's write and read buffers. I have confirmed that I am doing this correctly, because I get responses in the correct format: 0x02 0x?? 0x00 0x?? 0x00. The ?? bytes always give me the correct number of available writable bytes and bytes to be read, respectively.
I am also able to read messages from the bluetooth chip, as I always receive the expected packet when I perform a chip reset: 0x04 0xff 0x03 0x01 0x00 0x01, and after sending an HCI command packet I am able to poll for and read the responses described below.
The issue that I am having is that, whenever I check that the write buffer is available and attempt to send a full write message such as ...
header = 0x0A 0x00 0x00 0x00 0x00 (check write buffer... only sends rest of message if write buffer > 0)
HCI command packet = 0x1003 (example: Read_Local_Supported_Features)
param total length = 0x00 (i have also tried not including this byte at all and raising the chip select one byte sooner instead)
params: none
... I always receive the same HCI event packet in response, no matter the contents of my HCI command packet's body:
response: 0x04 0x10 0x01 0x00
This implies that I am having a hardware framing error with my SPI, and I have no idea what may be causing that. As I just described, the rest of the processes work fine, so the SPI bus seems to be functional in most cases. Has anyone experienced and been able to solve this issue before? If so, I would really appreciate any help you can offer!
Note: There are already a few forum posts about this from years past, but unfortunately none that have been resolved.
