Powering Arduino Nano and LEDs from 5V rail
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Hey guys,
I want to power a Arduino Nano from the 5V Rail of a Duet 2 Wifi (v1.4) and controll LEDs with it (I don't have heater or fan outputs to spare).
I will use one remaining fan output to control the state of the LEDs
Is there enought power to drive the Arduino Nano and approx 30 LEDs of a (300 LED/5m WS2812b LED strip)?
Best Regards
Adrian -
@taconite
I would say at a guess , NO , the best way is use a buck converter off the main psu. -
see this on how to do the wiring
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@taconite said in Powering Arduino Nano and LEDs from 5V rail:
Hey guys,
I want to power a Arduino Nano from the 5V Rail of a Duet 2 Wifi (v1.4) and controll LEDs with it (I don't have heater or fan outputs to spare).
I will use one remaining fan output to control the state of the LEDs
Is there enought power to drive the Arduino Nano and approx 30 LEDs of a (300 LED/5m WS2812b LED strip)?
Best Regards
AdrianArduino Nano: yes (although Arduino Pro Micro is a better one to use if it will take inputs directly from the Duet)
LED strip: 30 LEDs * up to 60mA per LED = up to 1.8A. That's more than we recommend drawing from the Duet's 5V supply; so no. -
Thank you for your replies!
Why using a buck converter when I could just bi-pass the buck on the Nano. My concern is more about the current draw from the Duet.
As my fans are running on 24V I will use a optocoupler to convert it to 5V
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Thank you @dc42
What is the recommended max current draw from the 5V supply?
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@taconite said in Powering Arduino Nano and LEDs from 5V rail:
Thank you @dc42
What is the recommended max current draw from the 5V supply?
2A total, less 200mA for the Duet and any current drawn by LCDs, endstops and Z probes.
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So I guess I will do it like that:
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Why the optocoupler ?
I can't see why you need one , if it is to switch the buck converter on you can find some buck converter which have a enabled pin. -
@peter247 With the PWM output of the Fan I want to control the color of the LED. e.G. 10% dutycylce = green. My Fan Voltage is 24V but the Arduino can only take 5V
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So if I have got this right you are going to power your arduino and looks like spi controlled leds from a fan with pwm ?.
your diagram makes not sense to me !!!!
Are you use spi controlled leds like dotstar ?
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So I kind of made it work with this scematic
Simulation show good results:
The Problem with that is, even if i just put on the Fan_PWM at 10% (S0.1) I get already 2.5V. Does anyone has an explanation of that? Because of that I am limited to less colors ("just 6").
This is the PCB I put together with an optocoupler, an DC/DC converter and an Arduino Nano.
