Hiccups on 3HC expansion board

[deckingman]

For info, I've just finished a print of about half an hour, ran an M122 part way through and another at the end - no sign of any hiccups

[jay_s_uk]

Ok, the issue is still there after swapping drivers so ignore that

[dc42]

I'm sorry for the delay. The new firmware was affected by a chip feature that didn't cause a problem in a debug build but did in a release build. It's taken me more than half a day to track it down and fix it, and now I need to review and remove most of my earlier attempted fixes. I should have a beta tomorrow.

[jay_s_uk]

@dc42 no rush

[dc42]

I've put a binary of the new EXP3HC firmware at https://www.dropbox.com/s/7rqp6pul9ip3yam/Duet3Firmware_EXP3HC.bin?dl=0. Please monitor it carefully when using it, it's had only a little testing.