The aim of the article is to describe driver for 0816 feeders (thanks to author Michael for his ideas and design) as the shiald for Arduino Mega 2560 combined with negative pressure regulation.

PCB nearly finished is at picture:

... and layout picture:

I built my own Arduino shield with possibility to populate chinese cheap negative pressure sensor XGZP6847A from AliExpress or Freescale sensor. The regulation can be controlled by G-code sent from OpenPnP software and it creates finally complete solution for the users.

Modified firmware for 0816 feeders driver (changes are commented by "jopl" word) is responsive for command "M155 D3 S2 PX HY" where value X is pressure and Y hysteresis (example: "M155 D3 S2 P-40 H10" => pressure -40 kPa and hysteresis 10 kPa).

Of course, one should set initially the scaling factor as well as the offset of analog input 0 appropriately (to have a range of pressure -100 to 0, i.e. serial command "M145 A0 S0.10 O-93" in my case).

The output 3 will be switching the pump based on sensor value after that.

Just a notice ... I used the modified module MP1584 for MOD2 position. I designed very small board to be used instead of linear voltage regulator, which uses components incl. MP1584 integrated circuit from chinese boards. I have got very good experience with this board, therefore I decided to rework it and use it here. I will publish PCB as soon as possible.

Modified code: OpenPnPFeedersDriverCode.zip

The design of PCB as gerber files, layout, schematics and BOM: OpenPnPFeedersDriver.zip