I started running out of space on the PIC16F15345, so I ordered what I thought was a drop in replacement with more memory. I made a mistake, the PIC16F18346 is not.

First issue is that it only has one UART port and I need two. I haven't looked through all the differences yet but trying to think through my options. There are no other 20 pin PICs that seem to fit. 

1. Use the 16F18346 and write or find a software defined UART library.

2. Go back to 16F15344 and see if I can squeeze everything I need into the memory. This is toughy because there is some geometry calcs that are needed. Also want to eventually use a bootloader for flashing.

3. Respin the board for a bigger MCU. I plan on respining the board eventually but not for this version. Seems wasteful to do it now.