I’m going to solder my first perfboard “hardware” project. It’s a quite simple RGB lamp controlled by buttons and via bluetooth.
I’m not really sure about a couple of things… Here’s my schematic:
In the schematic there’s a part missing ( a potentiometer wired to analog input , a pushbutton( hardware debounced) wired to DigitalPin2 that handles an interrupt, and a bluetooth module that sends and receives datas to and from a phone.) but that part is quite ready-to-go so i don’t have big doubts about it. ( Please don’t mind which Atmega328p pins i wired to the transistors 'cause i made it randomly)
My doubts are:
I’m sourcing power from a wall power supply ( 12 V ,1 A ) …the led strip is directly wired to the source, the standalone atmega328p and all the other devices are powered from the 5V coming from the 7805. with the rule of thumb, Atmega + Bluetooth + button + potentiometer are drawing about 400-450 mA…instead , my rgb led strip ( 60 cm) is going to draw about 300-350 mA… the question is… dropping 12 to 5 with 7805 is going to make it really hot? ( please note that all this circuit, the strip excluded, is going to be placed in a small plastic box)…So, do i need some type of heatsink ? maybe an intermediate 7809 could lightweight the 7805 work?
Do i need any blocking diode between the power source and the 7805 ( or maybe between the 7805 and the atmega chip) to prevent damages ?
is there any outstanding problem that i cannot see?