Introduction: Portable Solar Power Station
This is for the March 2014 Voltaic Build Night (Virtuabotix's first Build Night).
We conducted this build at the Virtuabotix, LLC shop in Colorado.
So the idea was to build a Voltaic Solar Panel, that could power and host an emergency communications network. This wasn't accomplished with the time, so we thought we should at least provide the proof of concept for the original idea. So, on that note, we created a Sun Tracking Power Station. Putting it mildly....it is pure awesomeness. We had to hold quite a few build nights for this project (actually 4). So needless to say, we went through a lot of energy drinks and coffee, but in the end......We have completed an awesome project that can only lead to better ones..
So.. Here are the details that we went for:
- Track the sun vertically.
- Track the sun horizontally.
- Power the entire system with the Voltaic Panel.
- Have a minimum of 500mA available to the user.
- Provide the user with a port to use for power/charging of devices.
- Small and portable design that could fit into a hiker's backpack.
So here we go....
Step 1: The Design
Step 2: The Parts
We started with different parts than what are listed below... After many, many, and many more design changes, we finally selected the following parts for the project..
- (x1) Versalino Uno (Comparable to the Arduino Uno, but better, cheaper, and we make them after all).
- (x1) Virtuabotix 4cm X 6cm dual sided PCB
- (x2) Virtuabotix DC motor with reduction gear (56:1)
- (x1) Polulu Dual DC/Single Stepper Motor Controller
- (x1) Selectable 3.3V & 5V 700 mA Breadboard Power Supply
- (x4) 3m screws and nuts for motor mounting
- (x4) 2m screws and nuts for electronics mounting
- Acrylic Sheets for casing
- (x2) Generic hinges with screws
- (x4) 5m bolts and nuts for casing
- Arduino IDE (Used with Versalino Uno)
- Computer for programming
- Bench power supply for motor testing
- Multimeter for testing electronics for shorts
- (x1) Voltaic 6W Charger Kit
Step 3: Breadboarding the Circuit
SO as you can see we spent a lot of time testing this circuit before we hard mounted anything. It is always a good idea to test small, not big. If you complete one step and test, you can always undo that single step if there are issues. That makes it a lot easier than going 5 steps, then testing and having to rebuild the whole thing to fix a single issue.
- We started with breadboarding the power distribution, Versalino Uno, motor controller, and light sensors. This was easy enough to accomplish. There were no motors connected in the beginning, we just used Serial Output in the IDE to verify which actions would be taken based on the sensor readings.
- We tested the motor to find the optimal power usage for our system. We used a standard power supply to see what the current draw would be for the motor at 3.5V. It is important to test where the current draw will be when the motor is bogged down as well. This will give you the worst case scenario that way you can plan your power usage in the rest of the system. After all it is unlikely that the motor will always run with zero interference..
- Now we attach the motors to the breadboard circuit. At this point we can verify that the motors are moving in the right direction for the sensor values.
Now....It is time to start assembling the system.
Step 4: The Circuit Build
Now it is time for the final electronics build...
- Assemble the components on the single platform
- Create the power/ground rails. This selectable power supply allowed for two to be created.
- Solder all of the connections between the components. This took a lot of time. You have to remember that when you are soldering on the back side of the PCB that it should be backwards from the view from the top.. That is a lot of words that can be misconstruing...so let me try it again. When you look at the top and can see all of the components, you have to flip the directions when you flip it over to solder on the bottom. We tried to keep the cables going to the individual parts a single color. This way we could more easily see the wires for let's say the pan motor. We figured this would help us to replace or trace down issues if there were any, without having to physically trace every single cable.
- Attach the cables for the individual pieces to the header.
That's it. Should be simple enough. If you are attempting to replicate this project, use the diagram in Step 1, along with these pictures and you should be ok...If not, don't hesitate to ask us to make it more clear for you. We are more than happy to help you assemble it if you need it!!!
Step 5: The Housing
Here we are. We have a working circuit that needs a lovely home. What shall we ever do to find one???
Well, this is a proof of concept (for the moment at least)... So how could we house the system and still allow for us to show people how things are working? How about a clear acrylic? Sounds good to us (obviously, we did go with this option after all).
- First, the design... We used ViaCad to design our layout. We opted for four corner bolts to hold the top and bottom on the sides. Then connect the sides with a puzzle box method(not sure if that is what it is actually called, but that's what we named it at least).
- We started with the measurements for all of the electronics and motors. That way we can add mounting holes for everything.
- Then we designed the spacers for the hinges of the solar panel. This allows the solar panel to lay flat on the top of the box.
- Then we cut it out with our handy dandy laser cutter.
- Finally, we start the mock up to make sure our mounts line up and that the parts all fit in general.
Step 6: It's All Coming Together
Now it is time to assemble everything together. I can't even count how many times we put it all together just to realize that we added (or didn't add) something before buttoning it up. That being said this step is fairly simple, put it all together perfectly the first time....unless you are us and it is 430 in the morning, then you are allowed to mes it up a few times.
Step 7: The Moment of Truth
This is the final testing stage. As you can see in the video, we messed up on the tilt motor. The original positioning of the motor was not conducive to being able to lift the solar panel. That being said, everything else worked as planned. We just have to figure out how to fix the tilt motor issue. Maybe we can solve this before the conclusion of this project...
Step 8: Wrapping Up
So, we think we were able to fix the tilt motor issue. We changed the shape of the lifting mechanism from a pseudo diamond shape to a circle. We offset the motor mount in the circle from the center to allow for a larger rotation angle on the solar panel. We hope to have a video posted soon for this. We hope to continue this project to turn it into a fully functional personal power station (depending on demand) where the ports can all be mounted into the casing, built out of wood, or some other undetermined material, to be more durable