Bill of Materials (BOM)
| Quantity | |
|---|---|
| Electronics | |
| Raspberry Pi Zero 2 W(H) | 1 |
| microSD Card | 1 |
| XL4015 Buck Converter Module | 1 |
| USB-C Pigtail | 1 |
| D4148 MOSFET Module (XY-MOS) | 2 |
| 1N4007 Diode | 2 |
| BMP280 Pressure Sensor Module | 2 |
| 12V DC VN-T1 Vacuum Pump | 1 |
| 12V Normally Closed Solenoid Valve | 1 |
| 12V Power Supply | 1 |
| Panel-Mount Socket for Barrel Plugs | 1 |
| Wires | |
| Heat Shrink Tubing / Electrical Tape | |
| (Optional) DuPont Connectors | |
| Screws / Fasteners | |
| M3x40 Socket Head Screw (DIN 912 / ISO 4762) | 18 |
| M3x8 Socket Head Screw (DIN 912 / ISO 4762) | 6 |
| M4x? Button Head Screw (ISO 7380) | 2 |
| M2.5 Self Tapping plastic screws | 4 |
| M3 short heat set inserts | 24 |
| Other | |
| Water pump reservoir | 1 |
| One-Way-Valve | 1 |
| T-piece | 1 |
| G1/4 fitting | 4 |
| Silicone or PVC tubing | |
| Epoxy / Potting Compound | |
| (Optional) Hotglue |
Electronics
Raspberry Pi Zero 2 W(H)
- W version comes without pre-solder header
- WH version with -> makes it easier as no soldering is requires
microSD Card
Rpi recommands at least 16GB, recommends 32GB, probably both to much -> check what really is needed as minumum
XL4015 DC-DC Buck Converter Module
stepdown 12V to 5V for powering Pi
USB-C Pigtail
powering the raspberry, powering over pins bypasses the fuse, while not stricly necessary it's recommended
D4148 MOSFET Module
- switching valve and pump on/off
- often sold ander name "XY MOS"
1N4007 Diode
- used as flyback diode for protecting the MOSFETs
- not 100% sure if right one as no datasheet for pump motor available, seems to work though
BMP280 Atmosphere Pressure Sensor Module
- absolute pressure sensor, vacuum value needs to be calculatet using current athmospheric pressue
- could be automated using a 2nd sensor outside of vacuum
- used because cheap and available as module
- diffrential sensors more expensive and not available as module
12V Vacuum Pump (VN-T1)
not 100% airthight, therefore one-way-valve in tubing path to not loose vacuum
12V Normally Closed Solenoid Valve
12V Power Supply
- with barrel plug
- I'm using a 12V/4A max. (48W) power brick I had lying around
- tbd: minumim wattage
Panel-Mount Socket for Barrel Plugs
- matching the plug on power brick
- tbd: hole diamter