Soft robotics is a new field of robotics that has been really heating up lately. Many soft robots are pneumatically actuated, meaning they move when they are filled with air. To fill these robots with air, many projects use syringes or squeeze bulbs that can be used to manually control the soft robot, such as in this tutorial (http://www.instructables.com/id/Air-Powered-Soft-R... This is great for simple soft robots, but if we want soft robots to function on their own, we will need an electronic pneumatic control system to inflate and deflate them autonomously. There are a few control systems around the Internet already, such as this one from the Soft Robotics Toolkit:http://softroboticstoolkit.com/book/control-board. Many of these are unfortunately very expensive and often overkill for small soft robots. This is where the Aerobox comes in. The Aerobox is a simple, battery powered, single output control system. It's single output is perfect for grippers and single actuators.
- 1/4” diameter magnets
- Adafruit Trinket
- L293D Motor Driver
- Wire (Solid core recommended)
- 1/8” Y connector
- 1/8” tubing
- 9v battery clip
- Solenoid valve
- Diaphragm pump
- Slide switch
- UBEC Buck converter
- 3D Printer
- Soldering iron
- Vice for soldering and sawing
- Flush snips
- Wire strippers
- Super glue
- Computer with Arduino IDE and Trinket library
Step 1: Solder on Headers
Take the header pins that came with the Trinket and clip them to size. Solder them onto each side of the Trinket.
Step 2: Circuit Diagram
Start by following the circuit diagram/schematic. It is best to start by just making the on-board connections, namely the wires connecting the Trinket and the L293D. It is helpful to color code the the different wires, like VCC - red, GND - black, Signal - Green. For help following schematics, check out this tutorial.
Step 3: Tubing
To build the tubing needed, cut two 1/2 inch long pieces of the 1/8" tubing. Connect one piece to the output of the pump and the other piece to the white end of the valve. Then, connect the two short legs of the Y-connector to the other ends of the short pieces of tubing.
Step 4: Pump and Valve
To connect the pump and solenoid valve, solder wires to the pump and tin the ends of the wires on the valve. Solder them to the motor driver as shown in the diagram. Make sure the pump is connected to pin 1 through the motor driver and the valve is connected to pin 0 through the motor driver.
Step 5: Battery Clip and Switch
To connect the battery clip, start by sniping off the barrel connector. Then peel apart the two wire and strip their ends. Solder the ends to BAT and GND on the Trinket. Then cut the red wire about an inch from the board. Strip the two new ends and solder them to the middle and one of the side pins of the slide switch.
Step 6: UBEC
To connect the UBEC, cut the red and black wires of the battery clip about an inch from the clip itself. Then cut the wires of the UBEC on both sides and strip all ends. Solder the ends of the UBEC to the black and red wires on either end of the circuit. Reference the diagram for this. NOTE: Make sure the UBEC is facing the correct way. The side with the capacitor should be the INPUT. Make doubly sure that this is correct, or else the Trinket could unleash the blue smoke monster.
Step 7: Test
Power on the Trinket by plugging a 9v battery into the battery clip. Flip the slide switch if it is not already on. If all goes well, the pump should activate cyclically (this is because the indicator LED is also connected to pin 1, causing the pump to pulse when the LED does. This will only happen in bootloading mode.).