Another Way Of Controlling DC Motor With AVR:

Here is a video of me controlling a 3V hobby motor by sending a pulse of current. It is the same setup & code as the 11 LED CHASER (a hack), except 1 LED has been removed (at PC5) and replaced with a N2700 (row 2-4, row 2 to GND, row 3 to MCU, row 4 to positive on motor, row 5 to positive rail plus to negative on motor) MOSFET setup to switch on a normal 3 volt hobby motor that requires more amperage (higher than the 40mA maximum that the ATmega168 can handle) than the MCU provides (also added a 5V voltage regulator as power supply is 6 volts). To avoid using a MOSFET, I could have used a pager motor (used for vibrator) that will run on 40mA) directly connected to the MCU and rail just like I do with the LEDs in my demos.

11 LED Chaser Effect (before hack above):

I noticed that the whole right side of the NerdKit has 11 accessible ports that 11 LEDs will fit in just comfortably. I was told I could only get up to 6 or 8 LEDs using math to do it, but my old stubburn way of programming step by step in C easily allowed by to do these 11. Here's a video (barebones microcontroller on breadboard). I do not use any fancy math with my code because my video shows it running off 3volts (2 AA batteries), complicated programming would have caused the MCU to "brown out" (not function right and glitch) with only a 3 volt power supply.

Below is my commented and refined 11 LED light chaser basic demo source code (if not using makefile from nerdKit, then put underscore in front of delay_ms to _delay_ms):

/* Comments by www.Nerdful.com Conviently 11 LEDs fit on the right side of the Atmega MCU. Pins PC0-PC5 and pins PB1 to PB5 are filled with LEDs. Let's make them a light bouncer effect! */ #define F_CPU 14745600 #include <avr/io.h> #include <util/delay.h> void sleep(uint8_t millisec) { while(millisec) { delay_ms(33); // easily adjust the speed for all sleep calls at once millisec--; } } main() { while(1) { DDRC |= _BV(PC5); // Set PC5 Output PORTC |= _BV(PC5); // Set PC5 High sleep(1); PINC |= _BV(PC5); // Invert PC5 DDRC |= _BV(PC4); sleep(1); PORTC |= _BV(PC4); sleep(1); PINC |= _BV(PC4); DDRC |= _BV(PC3); sleep(1); PORTC |= _BV(PC3); sleep(1); PINC |= _BV(PC3); DDRC |= _BV(PC2); sleep(1); PORTC |= _BV(PC2); sleep(1); PINC |= _BV(PC2); DDRC |= _BV(PC1); sleep(1); PORTC |= _BV(PC1); sleep(1); PINC |= _BV(PC1); DDRC |= _BV(PC0); sleep(1); PORTC |= _BV(PC0); sleep(1); PINC |= _BV(PC0); DDRB |= _BV(PB5); // Set PB5 Output sleep(1); PORTB |= _BV(PB5); // Set PB5 High sleep(1); PINB |= _BV(PB5); // Invert PB5 DDRB |= _BV(PB4); sleep(1); PORTB |= _BV(PB4); sleep(1); PINB |= _BV(PB4); DDRB |= _BV(PB3); sleep(1); PORTB |= _BV(PB3); sleep(1); PINB |= _BV(PB3); DDRB |= _BV(PB2); sleep(1); PORTB |= _BV(PB2); sleep(1); PINB |= _BV(PB2); DDRB |= _BV(PB1); sleep(1); PORTB |= _BV(PB1); sleep(1); PINB |= _BV(PB1); sleep(1); PORTB |= _BV(PB2); sleep(1); PINB |= _BV(PB2); sleep(1); PORTB |= _BV(PB3); sleep(1); PINB |= _BV(PB3); sleep(1); PORTB |= _BV(PB4); sleep(1); PINB |= _BV(PB4); sleep(1); PORTB |= _BV(PB5); sleep(1); PINB |= _BV(PB5); sleep(1); PORTC |= _BV(PC0); sleep(1); PINC |= _BV(PC0); sleep(1); PORTC |= _BV(PC1); sleep(1); PINC |= _BV(PC1); sleep(1); PORTC |= _BV(PC2); sleep(1); PINC |= _BV(PC2); sleep(1); PORTC |= _BV(PC3); sleep(1); PINC |= _BV(PC3); sleep(1); PORTC |= _BV(PC4); sleep(1); PINC |= _BV(PC4); } }