Hi Alice,
We can't program via ISP because we have not pinned out any of the protocols for this. We intend to program via SWD and then use a custom programmer to program via serial.
Our project was created for the LPC5526 but neither Rowley or Xpresso can connect.
Our programming header is copied from a working project which uses an LPC1313. I have followed the guide that you linked for setting up the debug port correctly and everything looks good. It also looks identical to the LPC55S28 dev board which I can program fine.
Can you offer any further advice?