Raspberry Pi 4 4B - Nextcloud - Choosing the right cooling & Connecting GPIO

[KITN]

Hi there,

I am building a Pi4 4GB in my DIY wooden case (20x30x10cm) and I am planning to run Nextcloud on it. The top cover is made of acrylic glas. Besides the ventilation

1. I plan to cool the Pi using this fan. I plan to drill some holes in the acrylic glas above the Pi for ventilation.
- Will this fan be enough or should I should I use a bigger fan? If I shoud use another fan like 40mm, 80mm, 120mmm which one can be connected directly to the Pi and needs no further voltage transformation?
- Are some ventilation holes enough If I stick with this fan?
- If I use another bigger fan I would drill a large hole in size of the fan in the acygrilic glas and mount the fan on the glas instead on the Pi directly
- Which GPIO Pins do I need to use for connecting the fan to the Pi?

2. I would use [ur=https://thepihut.com/products/adafruit- ... momentaryl]this[/url] pushbutton as a power button.
- On which GPIOs do I need to connect the pins for LED and Power?
- This are the only cables I can find which seem to need no soldering a crimping my own cables. Will they fit on the GPIO pins?
- Do I need to connect momentary open or momentary close on the connectors of the button?
- Which script do I have to install to make both the LED and the power button work?

3. Besides the fan and the pushbutton I have nothing more connected to the GPIOs. The harddrive is plugged into an active USB hub which is connected via USB 3.0
- Will I have any power issues or is everything okay like that (for the Pi I use the original Pi 4 power plug)?

[wildfire]

Hi there,

I am building a Pi4 4GB in my DIY wooden case (20x30x10cm) and I am planning to run Nextcloud on it. The top cover is made of acrylic glas. Besides the ventilation

2 questions...

Why such a large case?

Can you get Nextcloud for ARM architecture? Edit: Further googling suggests that you can.

[Imperf3kt]

With the size of your case, assuming most of it is empty air, you may not require a fan at all, a simple heatsink will work depending on the ventilation holes.

You can make one out of any metal and even some ceramics, but aluminium is recommended from a price to performance ratio.

[rbscebu]

KITN wrote:
....
1. I plan to cool the Pi using this fan.

That fan should be perfect for the RPi4B. For even better cooling you should also intall heat sinks on the four IC's (integrated circuits) in the RPi4B.

I plan to drill some holes in the acrylic glas above the Pi for ventilation. (May not be needed in such a large case but a good idea.)
....
- Which GPIO Pins do I need to use for connecting the fan to the Pi?

Positive (red wire) to pin 4 (+5VDC) and negative (black wire) to pin 6 (Ground)

2. I would use this pushbutton as a power button.
- On which GPIOs do I need to connect the pins for LED and Power?

The GPIO's will depend on the program you write to monitor the GPIO pin state.

- This are the only cables I can find which seem to need no soldering a crimping my own cables. Will they fit on the GPIO pins?

Yes they will work but do not be afraid of soldering. It does not take long to mast and after your first project you will almost be a master solderer.

- Do I need to connect momentary open or momentary close on the connectors of the button?
- Which script do I have to install to make both the LED and the power button work?

To manually turn the fan on/off with a NO (normally open) momentary push button you are going to need to write some programs and wire in at least a resistor and transistor together with the NO momentary switch. The program would need to monitor a change in state of one of the GPIO pins and then signal the transistor to open or close the power circuit for the fan.

Rather than manually turn the fan on and off, it is relatively easy to program your RPi4B to monitor its temperature and turn the fan on or off automatically as needed. This is very well explained here. Although this is for the RPi3, it will also work with the RPi4B. I had a slight scripting problem with the explanation but received great help from forum member pcmanbob here in this topic.

3. Besides the fan and the pushbutton I have nothing more connected to the GPIOs. The harddrive is plugged into an active USB hub which is connected via USB 3.0
- Will I have any power issues or is everything okay like that (for the Pi I use the original Pi 4 power plug)?

No.

[KITN]

Thank you very much for your nice and very helpful replies.

Why such a large case?

First of all I wanted to fit all the USB hub, the Pi, and the HDD in one case, where everything is interchangeable. More space means less fiddling in small spaces. Second I found the wooden box with the dimension of 30x20x15cm really cheap and so I could save costs.

I attached some images of my current state. Now that cooling is cleared up, I can position the pi and the HDD.

The GPIO's will depend on the program you write to monitor the GPIO pin state.

To manually turn the fan on/off with a NO (normally open) momentary push button you are going to need to write some programs and wire in at least a resistor and transistor together with the NO momentary switch. The program would need to monitor a change in state of one of the GPIO pins and then signal the transistor to open or close the power circuit for the fan.

Rather than manually turn the fan on and off, it is relatively easy to program your RPi4B to monitor its temperature and turn the fan on or off automatically as needed. This is very well explained here. Although this is for the RPi3, it will also work with the RPi4B. I had a slight scripting problem with the explanation but received great help from forum member pcmanbob here in this topic.

Oh I did not clearify enough, sorry. The power button is for shutting down (and turning on from shutdown) the Pi itself not the fan. Do I still need a resistor?

How to connect it then?

Yes they will work but do not be afraid of soldering. It does not take long to mast and after your first project you will almost be a master solderer.

Thank you very much for your kind words. I already soldered a few times (for other projects and years ago) so I am not completely new to it. If possibe I would prefer not to solder so everything is detachable easily, but still thanks.