how to power the Arduino nano

hi guys,

i’m new to arduino and i’m designing LED matrix controlled by arduino nano, but the problem i don’t know which way to power the arduino board so it can light the LEDs properly.

i attached my PCB schematic

hi guys,

i’m new to arduino and i’m designing LED matrix controlled by arduino nano, but the problem i don’t know which way to power the arduino board so it can light the LEDs properly.

i attached my PCB schematic

Hi,

Considering each leds draw about 30 mA of current(This may vary depending on the leds. Please, look for current rating in data sheet) The leds will draw a total of 1.92mA of current. Clearly way too much that an Arduino can provide.

So, try using MOSFETs (Simplest option) or more complex LED drivers (one like the Adafruit neopixel one) way too much complex.

Hope this helps. Best, Anshu Raj

P.S: I notice that the leds seems to be connected in parallel(In group of eight leds). So, under perfect circumstances the max current usage will drop by a factor of 8(this will also lead to drop in maximum brightness of the leds)

It looks like you'll be lighting only one LED at a time with this matrix, so a normal USB connection should work for starters.

please don't cross post! http://forum.arduino.cc/index.php?topic=525714

Threads merged.

Anshu_Raj: Hi,

Considering each leds draw about 30 mA of current(This may vary depending on the leds. Please, look for current rating in data sheet) The leds will draw a total of 1.92mA of current. Clearly way too much that an Arduino can provide.

I'd like to see your math.

My regular leds have a max rated current of about 30mA but when I put a 220 ohm resistor on a 5V pin to drive a red led with forward voltage of 1.5V it only draws (5V - 1.5V) / 220R = 0.016A, 16mA. And 220R is the most often used resistor with leds here, the red led will be brighter than needed as an indicator about 5x over.

A blue led with the same limiting resistor only gets (5V - 3V) / 220R = 0.009A = 9mA.

Uno can source/sink maximum 200mA through the board, But as pointed out, how many will be lit in any instant?