I have already started on replacing the Xaar head with HP45. It will make a printer at least 50$ cheaper to build. I am in process of finishing the mounts for the head and its driver unit. I still have to make a Maple Mini to apropriate connector PCB. For now i will be making it using toner transfer method. For now i still need to decide how I want to controll the head with the main unit. I will probably stick to SPI with communication simmilar to Xaar128. There is one problem as previous head had only 128 nozzles at 200DPI and the newer one has 300 at 600DPI. So if we take a look at how much data is needed for one sweep, where we write every pixel with one bit and 4 inch sweep length, we are looking at 192400 bits for previous head and 720000 bits. This is of course too much to store in a microcontroller or even send across the SPI due to possible communication fails. Because of this I will be probably doing a 2 slave SPI communication from SBC (beaglebone black or raspberry pi) to main controller and head controller. I will be sending packets with 16bits of data, first 9 being nozzle numbers and last 7 being run length. I will try to write the software on the SBC so it will arange the run lengths in a chronological way. This way I could also have the communication with only one byte of data (used to send the run length). For this to work I would also need another connection between the head controller and the SBC, this one being just a simple pulse to request data.

Anyway this still needs some thinking to be made, but meanwhile I can focus on gathering the needed materials or upgrading independent faulty bits (wiggle in the axis)