We have created a design board in accordance with with AN-B-023 (page 9 , fig 3, interfacing with external memory). The board contains Flash memory, FTDI UART and DA14580 obtained through Digikey.
We replicated connections from AN-B-023 and took DA14580 connections schematic from the Basic kit. The prototype created with the Basic kit and FTDI cable worked fine.
However I can not start the on-board DA14580 on out board.
Both 16M and 32K crystals work but the boot sequence does not start upon reset. I see virtually constant 1.8V output on the DA's TX after reset.
Can you please let me know possible troubleshooting ways?
Do chips supplied from bulk vendors come with a bootloader or they need to be prepped somehow?