I'm lOOking for some soldering advice

Help with Raspberry Pi Foundation Boards (Raspberry Pi, Pi Zero, Pi Zero W, Pi A, Pi B, Pi B+, Pi2 B, Pi3 B, Pi 3 B+)
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KE0FHS
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I'm lOOking for some soldering advice

Post by KE0FHS » Wed Oct 16, 2019 5:44 pm

With the RPi 4B, a fan is pretty much a requirement to keep things cool. Most 5v fans come with wires that have connectors that are designed to slide onto the 5v and Ground pins of the GPIO header, but of course that doesn't work when you have a hotspot hat.

So far, the only solution I've found is to solder the wires to the appropriate pins on the underside of the GPIO header, but my soldering skills are marginal, so I'm always sweating bullets when I do that with a nice, fresh RPi 4B! I've done it successfully twice so far, but I'd like to find a better solution.

One solution that works is the Pimoroni Fan Shim, but I'd like to find a solution that works with other fans. I guess one possibility that might work would be the ZUM Radio shim, but using that means not using a heat sink on the main chip, which I don't think is good option.

I've looked for some kind of wire connector that would connect to a single pin (basically, a single-pin shim), but haven't found one yet.

Any ideas for a better way to solve this?
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

AF6VN
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Re: I'm lOOking for some soldering advice

Post by AF6VN » Wed Oct 16, 2019 6:32 pm

https://www.adafruit.com/product/4079

Solder the fan to the BASE (as close as possible) of the appropriate pins, push onto the R-Pi, then put the radio board on top of the header.

--
AF6VN
Dennis L Bieber

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KE0FHS
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Re: I'm lOOking for some soldering advice

Post by KE0FHS » Wed Oct 16, 2019 7:24 pm

Thanks, Dennis. I found this, which I think will work, but it'll require a custom case to make room for it. I'm hoping to find a solution that would work with existing cases. If nothing else, I'll continue using my iffy soldering solution, but I'm hoping for a nicer and easier solution.
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gpio_1to2.jpg
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73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

KE7FNS
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Re: I'm lOOking for some soldering advice

Post by KE7FNS » Wed Oct 16, 2019 8:51 pm

What I've done is order some of these: (from a different site though no idea about that one just was the first one to show up in the search results)

Image

single 0.1" (2.54mm) Crimp Connector Housing: 1x1-Pin

Then I just use a needle and remove the 2x1 casing, and slide on the new 1x1 casing and I can split the wires. Then I plug the fan into an extra 5 volt pin and ground somewhere else on the hat, like an unused Nextion port.

You could also solder to the bottom (underside) of the RPi GPIO.
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Re: I'm lOOking for some soldering advice

Post by KE0FHS » Mon Nov 04, 2019 11:03 pm

So I found a solution that's a bit of a hack, but works well and completely eliminates soldering.

The solution came about after I tried using a Pimoroni Fan SHIM with an RPi 4B that has a radio/modem hat, but found it to be not very effective: the CPU temp quickly shot up into the mid-orange range (above 60 C). I'm guessing that's because there's too little room between the RPi and the hat for adequate air flow. (I should note that I'm using a Pimoroni Fan SHIM with another RPi 4B that I'm using as my shop computer, and in that scenario, the Fan SHIM performs quite well, keeping the CPU temp in the 45° – 50° range.)

Anyway, that got me thinking: I wondered whether I could use the Fan SHIM as just a shim to run another fan mounted in the case. The reason that's attractive is that it would eliminate the need to solder wires to the RPi 4B's GPIO pins in order to power the fan. (Any time I can reduce the amount of soldering I need to do, I'm a happy camper!)

So I snipped off the Fan SHIM's arms that held the fan and discarded them and the fan. Then I snipped the wires off the fan, connected the cut end to the case-mounted fan's wires, and plugged the other end, as designed, into the SHIM. The SHIM is mounted, again as designed, on the RPi's GPIO pins, beneath the hat's connector.
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fan-shim-snip.jpg
fan-shim-snip.jpg (25.2 KiB) Viewed 118 times
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Result: Works great! It leaves enough room to mount heat sinks on all the 4B chips and powers the 5v fan (I used a Noctua) just fine, keeping the CPU Temp below 40 C.

I wish there was some kind of plain GPIO shim available, but I couldn't find anything like that, so this seems like the next best solution.
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

KE7FNS
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Re: I'm lOOking for some soldering advice

Post by KE7FNS » Tue Nov 05, 2019 6:42 am

Seems like a decent and useful hack to me, Toshen.

It wouldn't take very much work to design and prototype your own shim. The hardest part would be making every other hole slightly offset so that it would force a good connection on the pins. (like the ZUM radio shim does)

Then you can order a set of 20 or so from jlcpcb or pcbway for relatively cheap.

Let me know if you want to design one, I'm up for it.
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Re: I'm lOOking for some soldering advice

Post by KE0FHS » Tue Nov 05, 2019 2:16 pm

KE7FNS wrote:
Tue Nov 05, 2019 6:42 am
It wouldn't take very much work to design and prototype your own shim. The hardest part would be making every other hole slightly offset so that it would force a good connection on the pins. (like the ZUM radio shim does)

Then you can order a set of 20 or so from jlcpcb or pcbway for relatively cheap.

Let me know if you want to design one, I'm up for it.
Ah, I didn't know about those services. (This is what I love about playing around with Pi-Star, I'm always learning new stuff!) Yeah, that would be fun. Seems like the best solution would be a shim that covers the entire length of the GPIO so that the hat sits level above it, but only pins 4 5V and 6 GND would actually need to be wired up, and they should go to something like a 2-pin JST male connector (maybe 2.54mm, like the nextion uses?).

Yeah, I definitely would be interested in this.
73, Toshen, KE0FHS
Playing with Pi-Star (unofficial notes about setting up and using Pi-Star):
https://amateurradionotes.com/pi-star.htm

kc7ngc
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Re: I'm lOOking for some soldering advice

Post by kc7ngc » Thu Nov 07, 2019 1:44 am

My Pi4 is running octoprint for my 3dprinter but I use the makerfocus PI4 Fan board.

https://www.amazon.com/gp/product/B07WMTNXZ1/

The case I use has inserts so it adjusts to different site hats so everything fits in the case. After playing around with PI cooling options I found that having air blowing directly on heat sinks was more important than pulling air in/out of case.

That that had been able to overlock my Pi4 without any issues. And for the price it was worth it as would have taken me more time to come up and fabricate an alternative.

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