AVR in sleep mode. (power saving mode)

I used AVR tiny13 for small applications very often, and mostly it is powered by only small battery. It is easy to put the AVR MCU to power save mode with avrlib, just few lines of code would do. To wake up the AVR MCU, you should setup interrupt before falling into sleep mode, either pin change interrupt or external INT0.

Here is my sample code (waked up by pin change interrupt)

//do nothing in interrupt func.
ISR(PCINT0_vect){
        cli();
}


//main code:


//setup interrupt
    GIMSK |= 1<< PCIE;
    PCMSK |= 1<< PCINT0;

    on_bulb(); //turn on light bulb

    while(1) {
                b1_low; //turn off
                sei(); //enable interrupt
                set_sleep_mode(SLEEP_MODE_PWR_DOWN); //set sleep mode
                sleep_mode(); //sleep now
//wake up point here //

                while (PINB & 0x1) { //if PINB is high
                        on_bulb();
                }

    }

I only measured once I finished the demo circuit, and it should use around 10 times less power when AVR is in sleep mode. Have fun.

Convert Wave to energy by snake.

Hydrogen Fuel Cell Toy Cars.

Hydrogen fuel cell is the next green source of energy, by breaking down water (H2o) into hydrogen (H2) and oxygen (O2), the hydrogen can be used for energy generation afterward.
It is still a long way to go in normal usage, but how well is the technology now?

Horizon Full Cell Technology introduced a Toy Car using their fuel cell technology. You can buy a toy car in affordable price to taste this bleeding edge technology.


Check out the youtube video:





Links:

Horizon Full Cell Tech Toy:
http://www.horizonfuelcell.com/tech_toy.htm

RC model:
http://www.horizonfuelcell.com/rc.htm

Solar Power, the green power source.

Solar Power Charger

Solar power is not a news nowadays. People are finding better ways to get power without harming the earth. To use of solar power, you need the solar panel that converts solar energy to electricity. So how to make a small solar charger for your home use? This solorb's website teaches you how to make a simple AA battery solar charger, few components are needed, a nice choice for your home project.





The project needs few solar cells, and 1 1N5818 Schottky Diode and of course the AA rechargeable battery. Why Schottky diode? this diode have less voltage drop when current flow through, it is important as we want to be sure the energy is not wasted on the diode which is only used for preventing the current through back to damage the solar panel when the charger leave in the darkness. You can also buy the solar kits from the author website as well.

Take it into real life application, you may add the solar charger to your radio! Let's read the tutorial bought you by gotwind.org "DIY Solar Powered radio for $5", the theory is the same as the AA charger.



Another video showing a home-made solar USB power charger:

Solar Powered USB Charger - Cheap And Easy To Make! - The most popular videos are a click away

A very comprehensive study on Solar power charger: REUK.co.uk - Solar Battery Charging.