Cooler Waveshare?

[mhschmall]

I have a lot of rpi stuff and I noticed that one of the small heatsinks (9mm) is just the right size to fit on top of the esp32. The problem was that placing the heatsink pretty much locked the sd card in. Now that we have file control, you really dont have much need to remove the SD card. A quick hole in the back cover and now there is thermal cooling of sorts. Modified cover has been included.

nomadbackcover.zip

[mhschmall]

Here's an amazon link to some nice copper ones: https://amzn.to/4oaFCLQ

[alfem]

I wonder if a short strip of aluminium (from a soda can?) could be used to carry the heat from the esp32 to a heatsink in the other side of the board (or out of the way of the sdcard).

[mhschmall]

In theory, yes. Snip, stick, and pic. Please post your results. Ive posted a code snip below that you could use to measure how well your solution works.

[Jstudner]

When I was building this just for me I had planned to machine the housing from aluminum and having a bump behind the SD card touch the processor, this is a good solution though. I am currently working on finding a SD card extension board that would allow it to sit further back and be accessible without removing the case, in which case thermal paste/pad will probably do the trick.

[mhschmall]

Im curious to see how that goes: You see, that red thing on the end is your antenna. So if you cover it up with an extender/sd card, does it attenuate the wifi? Does moving the SD card closer to the antenna affect the SD card in a negative way? questions, questions.

[Jstudner]

To be discovered, I doubt it's going to have an effect on the SD card (and having it away from the processor will be great cause the heat does cause issues). But it's definitely going to interfere with the antenna, just a game of how much. I really really want to have the ad card accessible without opening the case (I tried using other boards but it's tricky to find one in the same form.) might even be worth soldering a new antenna on, though I do want to keep production simple. We will find out though! That's the fun of these projects!

[Jstudner]

as an update the SD extender is working great, The ones I can get on amazon are the perfect height, and while it goes in a bit crooked due to hitting those back screw mounts it should be fine if I design around it. fixes my biggest issue with how to load files to the device.

As far as I can tell there is no change in my benchmark results, but I think I am going to setup an actual code for testing to be a bit more accurate (right now I just open 6 movies and see how it handles lol). SD card is a bit further from the processor so better for heating, and the back of the board is coated so I don't think it will mess with the antenna much.

[mhschmall]

With this unit up in the air with modest air flow, I only saw a 5c up swing under load (as reported by the processor). Not bad for grabbing something out of drawer and 5 mins in Tinkercad.

[Jstudner]

that actual huge, I would love to see the direct comparison, what method are you using to test the load? I will do some testing on my end before production with a few thermal solutions.

[mhschmall]

I slipped this bit of code into loop():

if (millis() - lastTempReading > 6000){
float chip_temp = temperatureRead();
   Serial.print("current temp: ");
   Serial.print(chip_temp);
   Serial.println("c");
lastTempReading = millis();
}

and then ran the unit with it sticking out of my laptop. Doing nothing, it warmed up 50c. Then I initiated some downloads and saw the temp rocket up to 64c. Thats when I flipped my laptop on its side so the board was sticking up in the air and there's modest airflow in my office. The temp dropped back down to 55c. Doing further downloads like this showed a swing between 50 and 55c between rest and load respectively.

[Jstudner]

I might actually add this to the admin panel, If nothing else I am going to do some testing with it, would love to lower the temps before production! Thanks as always!!!

[mhschmall]

Ok, lets go full geek and put that RGB led to use. This sets the led color to correspond to a heat range. Could make a nifty LED mode switch.

if (millis() - lastTempReading > 6000){
float chip_temp = temperatureRead();
RGB_SetMode(2);
 if (chip_temp > 62.0){
   RGB_SetColor(255, 0, 0);
 } else if (chip_temp > 59.0){
   RGB_SetColor(255,128,0);
 } else if (chip_temp > 54.0){
   RGB_SetColor(255,255,0);
 } else {
   RGB_SetColor(0,255,0);
 }
   Serial.print("current temp: ");
   Serial.print(chip_temp);
   Serial.println("c");
lastTempReading = millis();
}

[Jstudner]

well now I gotta write a whole RGB customizer panel code like my PC motherboard has lmfao. that's so cool though, I might add that as a mode when I get a chance!

[Robin-Sch]

Hey, is the zip file you included based on the newer stl file that is included in this repo or the old one? If not, how/where did you made the hole (and how big) to fit the heat sink? Is it the already existing cutout or is that for the microsd?

[Jstudner]

This version happened after, the heat sync won't fit with a SD card extender installed (it goes over the processor). I will update again soon with clips, it holds well enough but different printers have issues. I am also experimenting with cooling it with thermal paste, but still working on it.

[Robin-Sch]

Oh that's a bummer, I thought I could do a combination of both extender and heat sink... Maybe there exists some right angled SD card extender?

[Jstudner]

The SD card extender is a straight shot, I think the better solution might be cutting a soda can or something aluminum, sticking it on with thermal paste and bending the edges around the SD card extender.

[mhschmall]

I had posted the stl file for the back side with the heatsink hole in the OP, but its easily missed. Here it is again:

https://github.com/user-attachments/files/21569617/nomadbackcover.zip

really really really recommend a high temp plastic for the back cover: ASA, PETG, ABS