The aim of the article is to describe the driver for 0816 feeders (thanks to author Michael for his ideas and design) as the shield; 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 the ability to populate cheap Chinese negative pressure sensor XGZP6847A from AliExpress or Freescale sensor. The regulation can be controlled by G-code sent from OpenPnP software and it finally creates a 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 a very small board to be used instead of a 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