Arduino/wiring help.

MadG4mer · June 29, 2016

This is my creation after searching whole morning for information from the internet. The purpose of the Arduino is to be my little assistant in controlling my PC and its lighting.

What is the smallest Arduino I can use and how do I power/wire it? What pins can I use?

I will need total of 6 PWM pins and RX and TX pins for the BT module.

Huntsman · June 30, 2016

Arduino Micro or Nano might fit your needs. They're essentially a smaller version of the Uno, they have the same chip. Beware that there are 5V and 3.3V variants.

You could power it using 5V from USB so that saves you alot of hassle. You might need to use the 3.3V regulator on the Arduino itself for the Bluetooth and also the signal level needs to be converted to 3.3V for Bluetooth. Most Bluetooth modules work on 3.3 instead of 5V. You might want to use SoftwareSerial for the Bluetooth module instead of using the hardware serial as it will be shared with USB.

How are you using the opto for power switch?

MadG4mer · June 30, 2016

@Huntsman I will use the opto as secondary power switch with the secondary power switch pins that my motherboard provides. I just need to code the opto to allow passthrough for like .5 or .3 seconds which allows the pc to power on.

Huntsman · June 30, 2016

Can't you just use a jellybean transistor to do it? You only need to short the pin to ground to power the mobo on right? Optocouplers are more expensive than transistors.

MadG4mer · June 30, 2016

1 hour ago, Huntsman said:

Can't you just use a jellybean transistor to do it? You only need to short the pin to ground to power the mobo on right? Optocouplers are more expensive than transistors.

Actually from ebay optos are like 0.5€ for 10 pieces which is pretty much same as the transistors would be (dont have any excess components available)

WEEEEEE · July 7, 2016

On 6/29/2016 at 10:08 PM, Huntsman said:

You might need to use the 3.3V regulator on the Arduino itself for the Bluetooth and also the signal level needs to be converted to 3.3V for Bluetooth. Most Bluetooth modules work on 3.3 instead of 5V.

I've used Bluetooth modules in the past, the voltage can be stepped down by a simple voltage divider, since they don't require much current.