- Shohreh Kia
- Anant Sujatanagarjuna
The above figures show the components used to prototype a pneumatic harvesting system for Oyster mushrooms.
This system actuates a blade (B) which is mounted perpendicularly on a bi-directional pneumatic cylinder (C). The cylinder is set up to harvest oyster mushrooms growing from our developed mushroom pods. The pneumatic tubes T1 and T2 control the motion of the pneumatic cylinder. Depending on whether T1 or T2 is pressurized, the piston rod moves outwards or inwards from the cylinder, respectively. When both T1 and T2 are pressurized or depressurized, the piston is immobilized or free to move, respectively.
For the purpose of harvesting, T1 and T2 must be pressurized and depressurized alternatively. This is accomplished by the 5/3-way solenoid valve (SV). Internally, two solenoids control the valves pressurizing T1 and T2. These solenoids are activated by 12-volt DC magnetic coils MG1 and MG2 . These coils are digitally controlled by 5-volt relay switches connected to a Raspberry Pi 4B, programmatically controlling the entire setup.
For simplicity, we use a an analog joystick to control the 5-volt relays, however it is also possible for them to be actuated remotely and automatically.
The above ciruit diagram was created using Fritzing.
joystick_control.sh is the accompanying control script.