RGB WIFI Dimmer

To control the LEDs I created a small HTML site with some buttons, range and select options. At the moment it sends the informations to the server (ESP8266) where they will by interpreted and converted to UART for the ATmega8.

After a while of trieng I finished the hardware, one problem was to get the best values for the gate resistors, another problem was that I forgot to add a +3V3 connection to CH_PD of the ESP01 header. As you can see on the picture all is working fine. The voltage drop over the N-FETs is below 0.02V.

Here some facts:

power input : ESP01 + PCB = 90mA * 12V = 1,08 (HelloServer.ino)

power input : PCB = 20mA * 12V = 24mW

warm white leds 5660 600 = 850mA * 12V = 10,2W/m, voltage drop 0,5V after 1m

RGB leds 5050 = 1,1A * 12V = 13,2W/m, voltage drop 0,5V after 1m, all three colors on max

Today I tested the N-FET construction with small pieces of LED strips. With all four PWM channels, all of them have around 500Hz an can have any duty cycle. The main result of this test is, that I have to choose other values for the pull-up resistors. I choose 3k3 for 3V and 4k7 for 12V.

For the tests i used a breakboard from al1. https://hackaday.io/project/6768-atmega8-breakout

Today I wrote some lines codes for the project and checked the results with an oscilloscope. I created 4 PWM signals, three with the Output Compare Registers of the µC and another one with timer0 by using an ISR. The slowest PWM has 600Hz and the other three have about 30kHz frequency which I want to use for the RGB LEDs.

void ATmega8_PWM_8bit_Software_timer0(uint8_t value)
{
	softpwmvalue=value;
}

void ATmega8_PWM_8bit_Software_timer0_setup(void)
{
	DDRD	|=(1<<PORTD5);		//set D5 as output
	TIMSK	|=(1<<TOIE0);		//Counter0 Overflow Interrupt Enable
	TCCR0	|=(1<<CS00);		//set prescaler to 1
}
ISR(TIMER0_OVF_vect)
{
	static uint8_t counter;
	counter=counter+1;
	if (counter>softpwmvalue)
	{
		PORTD &= ~(1<<PORTD5);			//off
	}
	else
	{
		PORTD |= (1<<PORTD5);			//on
	}
	
}