Introduction: Solar Powered Arduino Survival Kit
This instructable will detail the creation of a multi-purpose, high tech Arduino survival kit. The key modules we will be focusing on in this tutorial is a rechargeable battery pack, a solar panel serial setup, an electronic buzzer, and a GPS+Bluetooth module. This combination of items will allow you to scare animals, alert rescue responders, and recharge your phone and track the path of your mobile Arduino setup.
Much of the code and materials made available in this tutorial are made possible thanks to the open source community and the thriving world of creators who are willing to help one another.
A web application has also been written for this module. This will allow you to walk without your phone and still be able to track your long hikes and journeys and visualise them using Googles Maps API. This is a simple to write program and can also be done by yourself if you wish to change the aesthetics or features of the page. Do note however that this must be opened in Chrome as it uses the latest and greatest web to Bluetooth API's.
Step 1: Requirements
The technology used in this tutorial are as follows:
An Arduino Mega 2560 (Along with a USB-A to USB Type B cable to upload code)
4x Flexible Solar Panels
A Seeed Studios Solar Shield v2.2
An HM-10 Bluetooth Arduino Module (Supports Bluetooth 4.0 which is important for interacting with modern devices and web pages)
A GPS Module
A simple button
Any eletronic Aduino buzzer
A 5000mAh battery pack that supports charging via micro-usb and discharging via USB-A.
A breadboard for ease of use and testing
A lot of wires!! (Male to female, Male to male, Female to female, power cables capable of small currents)
Small terminal heads
USB-A cable to anything
Micro-USB cable to anything
Step 2: Power Setup
The most important part of our mobile setup is ensuring we have power on the go. We will make use of the Seeed solar shield to protect our components as we create a 6 Volt system with our solar panels. The Seeed Solar Shield can handle a Solar input voltage of 4.8~6 volts. Feel free to play around with this range by either supplying extra voltage and stepping it down or by wiring your circuits in different ways.
Step 1: If your Solar Panels lack connectors, you may have to pry into the back padding to find the metal contact points for the positive and negatives nodes respectively. Otherwise, if you do have wires with your panels, ensure they can be wired in the attached wire plan above. Cutting and resoldering your wires might be more convenient depending on the connection.
Step 2: Soldering a male wire to every positive pin and a female wire to every negative pin will allow you to extend your solar panels as needed. Depending on your usage of this survival kit, this wiring option gives you greater flexibility depending on your workspace and needs.
Step 2.b: It is a good practice to test your wirings with a voltmeter. If working in the dark, a flashlight from your phone camera should be enough to send some small amounts of voltage that will be visible.
Step 3: Once you have a series circuit of solar panels, (If using the ones we described in the requirements, you should now have a potential of 6 Volts), you can begin plugging them into the Solar Shield under the terminal labeled 'Solar'. If your wires do not plug in to this port, you may have to solder an end terminal on to your wires so that you can connect to this.
Step 3.b: Much like the above step, you will likely be unable to plug in your power bank directly to the battery terminal, especially with a commercial styled power bank. It is likely you will have to cut the cable and use a solder to mend the wires such that it can be plugged in to the battery terminal for solar charging.
Step 4. Also with the powerbank, plug it in to the microUSB port on the solar shield. Our powerbank charges through MicroUSB, and discharges through USB-A. With a program to monitor the charge and discharge, you should be able to make full use of your powerbank regardless of its ability/inability to charge and discharge at the same time.
The Solar Seeed Shield provides a red light to indicate when power is coming in from the Solar panels. This can be helpful in testing!
Now that we have our powerbank suitably prepared for charging, we can bring along your selected phone charger such that you can power your phone on any journey! USB-C, Lightning, Microusb, you name it!
Step 3: Bluetooth and GPS Modules
It may be useful to use a breadboard for the following steps, depending on whether or not you are using a smaller Arduino.
For these steps, we will be using the SoftwareSerial library. If you have been following along on a different Arduino from the Mega, (Such as the Arduino DUE), you might find you lack the libraries to continue with the following code and steps. I personally struggled to find workarounds on the DUE and made the switch to the MEGA 2560.
Step 1: Pins
HM - 10
The HM-10 can step down 5 Volts, so feel free to plug it in to either the 3.3 or 5v pin
vcc - 5v
tx - 11
rx - 10
gnd - GND
Note, the antenna must be separately connected to the receiver. If you struggle to make this connection, (It should not take too much force and should result in a satisfying click), then you may need to take some pliers and shorten the width on the microcontroller of the module. On the Antenna side, the connector should be slightly flared, so do not try to slim this down or you will struggle further.
vcc - 5v
rx - 18
tx - 19
gnd - GND
Since these two modules can both handle 5 Volts, it can be more convenient to wire them in series on the Breadboard. The GPS Module will not blink red until it receives a strong satellite connection, you may need to go outside and wait a couple of minutes for this to occur. However on subsequent usages this should become a much faster process and possible from tougher satellite conditions such as the indoors.
With the GPS Module and a larger memory from the Arduino Mega 2560, we can send our GPS data to bluetooth devices, and create maps through various web applications.
Link to code below
Step 4: (Optional) LED Button Wiring
As you may well know, buttons can be wired via a simple two pin connection. When the button is pressed, the connection between these pins is restored. Many LED buttons will also contain extra pins for lighting. This separates the physical logic of the light and aesthetic and the actual purpose of the button. Our button contained a label for the positive and negative connections for wiring, however we lacked the wiring for the I/O pins. This may require some testing or fiddling around.
Step 1: Take your button with prong 'pins' and instead solder male wires to them so that the button can be placed in either a breadboard or directly into your Arduino.
Step 1b. Adding heat shrink and electrical tape can be an excellent way to ensure the stability of your newly soldered on wires. Skipping this step will save time but cause greater uncertainty when you are testing your new fancy button, especially when already running in to labelling issues.
Step2. Test your button and add any logic you like to it, such as turning on the bluetooth or acting as a button for our buzzer which will be installed in a future step.
Step 3: Make sure to include a debouncer in your code whatever you end up using the button for. Debouncersare a great way of making electrical currents intuitive and usable for programming.
Our button is placed under the 3.3v line along with a ground. The other pins are in 5 and 6 respectively and control our buzzer.
Step 5: Option 2: Normal Button
If you wish to minimise soldering and confusion, feel free to instead opt for a normal button. This will usually be better labelled and will provide a much more tactile click, which is easier to test.
Step 6: The Buzzer
A buzzer at the correct frequency can be a fright to animals (and potentially, annoying small children). A resistor can be used to make sure you don't blow the buzzer, as it does not require to full 3.3 volts that our Arduino can output.
The Arduino Mega 2560 has pins to spare, and our three pronged buzzer is plugged in to pin 47, largely to keep is seperated and organised from seperate components.
Step 7: Application: Optional Steps - a Solar Powered Jacket
Solar panels placement :
A recycle plastic pocket is made to perfectly fit in the 4 pieces of lightweight and flexible solar panels which have a metal ring hole that is for the wires to go through to the middle layer of the jacket to reach the power bank for charging on the left-hand side of the smart jacket. It is placed on the front because long distance hikers would carry big backpacks for staying over-nights there placing the panels at the back would definitely be less effective than putting them on the front.
Recycled transparent plastic, therefore it will not affect the functions of the panels as it allows sunlight to go through and also being water resistant which can prevent the wire from being damaged.
There is also a rectangle stripe covering the metal ring that allows connection between the batteries and the panels which is measured precisely for only covering the wire connection but not the surface of the panels.
Sizes: plastic pocket allows 4 (195mm x 58mm each) solar panels neat and efficiently arranged in a drop pattern.
Materials: Waterproof fabric and zip lines, recycled plastic, metal rings, plastic buttons,
An intelligent three-layer design can be used to protect your wiring and also provide comfort to the user. By separating the wiring from both the outside and inner layers, you not only allow yourself more room to work but you will ensure your user will be none the wiser as to the power and complexity of your Arduino Survival Kit!!
Step 8: Application: Optional Steps - a Smart Jacket
LED lights can also be placed on the shoulders and sleeves of the inner layer of the clothes while the to further enhance the survival components and visual aspect of the jacket. Intelligently chosen low power LED's will make a limited impact on the powerbank and still maintain the purpose of our mobile Arduino module. Ensure proper care is taken to not overheat any clothing and electrical components, such as by turning on for long periods of time. Feel free to leave your phone behind and go for a hike, when you return you will be able to upload your gps co-ordinates onto our web application linked in the first step of our instructable.