Altoids Solar Powered Emergency Device - ATtiny 85




My first instructable...

This is an emergency survival kit with ATtiny85 it has many features for outdoor survival whilst also providing means of help via morse code SOS flash...

The device itself is run of 3 AAA rechargeable batteries that charge via solar panels attached to the lid of the tin, the device can charge up USB powered devices charges up super bright LEDS that flash SOS. 

and whatever else 

Tools Required

1. Solder Iron - with solder (of course).
2. Usb Connector 
3. 2x 10uF and 1x 1uF electrolytic capacitor
4. 5V Regulator 
5. 560 Ohm resistors - (Or anything suitable) 
5. ATtiny 
6. A few LEDS
7. Glue Gun
8. Wire
9. A tin - preferably metal 
10. A plain PCB - would use less room than a copper strip board    

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Step 1: First Steps USB Charger

Due to my buying a stripboard i need to use more space on the board, but first steps ...

Cut the board to the shape of the tin but leave some gap at the front and right side for the LEDS to go.

I used this tutorial on how to make a 5V regulator .... This circuit worked fine with a 9V battery outputting just over 9V to the usb with exactly 5 volts...

I created  2 strips on the board ground & live that way it was easier for me to connect everything 

Solder everything into place and you have a USB charger (once you connect a battery).

I positioned the 5v reg to the back of the board that way when everything is in place i can attach it to the tin and use the tin as the heat sink,

Step 2: Battery Placement & ATtiny SOS

I connected the ATtiny one straight from the USB power source and the other from a push button so that when the button is pressed the ATtiny will come alive and start flashing the SOS morse code,

I have no super bright LEDS so i just used a blue led

The code used for the ATtiny85 to get the SOS...  

int pin = 0;

void setup()
  pinMode(pin, OUTPUT);

void loop()

void dot() {
  digitalWrite(pin, HIGH);
  digitalWrite(pin, LOW);

void dash() {
  digitalWrite(pin, HIGH);
  digitalWrite(pin, LOW);

Step 3: Test That Everything Works With a 9v Battery

At this point i tested mine with a 9V battery check all voltages and that everything worked, on my first one i had trouble with incorrect voltages throughout the board,   Once tested cut the board to the correct size, and make holes within the tin that align with the usb, leds, buttons & switch

Cover the tin with electrical insulation tape a colour of your choice - i only had green

Step 4: Solar Panels Installation

The solar panels i found were cheap panels from garden ornaments they had no information on the reverse other than a + -,

I tested these and 4 panels were outputting 9v and almost 4v inside my house, i then drilled a hole in the lid of the tin for the wires and glued the panels to the top of the lid,

I soldered the 3 batteries together and taped everything together to keep all solder joints safe i then attached everything the the stripboard

Step 5: Emergency SOS Button Placement

I attached the button at the side of the usb and connected a light at the back of the tin

Step 6: Finishing Touches...

I connected the solar panels straight to the circuit board so that it won't over charge the batteries but will if a sunny day allow for using the USB and SOS without batteries, but flick the power switch and place in the sun to charge the batteries In my house i have to use the batteries to power the usb but outside i can switch the batteries off and use the solar panels

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    2 Discussions


    4 years ago on Introduction

    a dc dc converter is a great upgrade over that 7805 in terms of efficiency. Please air cooling for the photovoltaic panel will help it immensely.


    5 years ago on Step 2

    nifty idea.
    not that it really makes a difference, but you can spare a byte by changing int pin=0; into byte pin=0;
    but i guess one could care less in the wild. :-)