I've been struggling getting the 4-wire UART communication going for a coworkers design. It uses the WLCSP SAML21J18B and the ATBTLC1000A-MU-Y. It is not currently working, so I went back to the dev boards to see if the example broadcast projects work.
Between the Xplained Pro boards (both SAML21 and SAMD21) and the BTLC1000 Xplained PRO board connected on EXT1, I can see the 6-Wire UART work well. The bluetooth is advertising appropriately and the LED indicates it has reached the broadcast part. From here is when I start running into issues. So far, I've been following the advice from threads and the datasheets:
1. Updated the symbols (UART_FLOWCONTROL_4WIRE_MODE=true, UART_FLOWCONTROL_6WIRE_MODE=false)
2. Kept the BLE_MODULE=BTLC1000_MR
3. Removed U102, R116, and R117 from the BLE board.
1. BluSDK release notes imply the fuse needs to be set. It also says the EfuseBlockProgram.exe can do so. Where can this be found? It says it's supplied, but where?
2. I have an Atmel-ICE device for programming. Can this be used instead of the SAM-ICE as specified in the BluSDK release notes?
3. Can the WLCSP BLE device use 6-wire UART at all? What makes the -MR version unique in that it can handle both 6 and 4-wire, but the WLCSP cannot?
4. Does the WLCSP BLE device fuse setting default to using 4-wire?
5. Has SPI communication between the BLE device and the MCU been released yet?
I've done a lot of searching on the forums already and found similar threads. The first seems to have the most similarities to my issues:
Thank you for any direction you can provide,