presoldered ESP32 module

[rziegaus]

Hello,

I am looking for a ESP32 module that is already presoldered AND that is not a development board.
The development boards I have found use a lot of current so they won't last very long when run on batteries.
The current modules I have found however are very hard to solder at least for me. So I'd like to have ESP32 modules which are already presoldered.

Any ideas? I have done an extensive search, but to no avail.
Does anybody have a recommendation for me?

Thanks,

Rudi

[kolban]

The raw ESP32 is a 5mm x 5mm IC that can be surface mounted. By and large it is not usable for hobbyists like me. The next level up is the WROOM and/or WROVER modules. These are ESP32s with flash encased in a small PCB inside a small module. They have no "pins" but can be just about soldered. The next step up are one of the many boards that exist which host either raw ESP32s or WROOM/WROVER modules. These have pins suitable for a bread-board or wire plugging. From your post, it sounds like the WROOM/WROVER modules may be what you need.

[rziegaus]

Hi Kolban,

thanks for your reply. Yes, that sounds like just what I need. Unfortunately I can't find any of those modules. I only find modules where I would have to solder the module to a break out board. Given the many pins and the tiny dimensions I would have to do SMD soldering which I can't because of lack of equipment.

If you know of modules where I only need to solder the pin headers I'd be glad if you could recommend a source for that kind of modules.

Thx a lot,

Rudi

[kolban]

Here is an example of a WROOM ....

https://www.ebay.com/itm/ESP32-WROOM-32 ... Sw32lYtNZr

The pinspacings are small (1mm?) but MUCH larger than a raw ESP32 IC.

Here is a mounting board with breadboard sized pin spacings:

https://www.ebay.com/itm/ESP-WROOM-32-E ... gk-iulXHTw

Beyond this, I doubt you'll find pre-soldered WROOM modules on boards.

[neltnerb]

I wonder how much of your issue with using a development board is purely that they use a linear 5V to 3.3V regulator. They just throw 33% if the power away right there. Seemed like a strange choice for a low-power chip, but I suppose it's a lot cheaper.

Depending on your system, you might be able to decrease your current by 25% or so simply by replacing their linear regulator for a more expensive switching regulator. On my board, the Core board v2 / devKitC, it's a NCP1117 linear regulator in a SOT-223 package.

It probably can't be done with a drop-in replacement, but you could just not connect anything to the development board power input, remove their 3.3V regulator, and connect a wire directly from your board to the 3.3V output of that linear regulator to use a switching regulator or module you put on your main board.

[rziegaus]

Thanks for your links - I know these modules, but could not tell before I saw your links.
However I find these modules hard to solder - at least for me.

How would you solder these modules? The best way would be a reflow oven, but unfortunately I don't have such a beast...

Rudi

[kolban]

For me personally ... I am about 50/50 in success ... sometimes I can do it just fine, other times I make a complete mess of it - soldering by hand. How many instances do you need? Is this a one-off and if not, how many do you need?

My hands shake and I have no dexterity ... however younger folks with better eyes and motor control are likely to fair far better. If I really had to do it, then I'd make a solid mount for the board and lock the module down before soldering at least one pin. I'd use a very fine tipped soldering iron with fine solder. I'd also apply flux to the edges to be soldered. Then under a dazor style magnifying glass tackle the puzzle. I have no magic beyond that. I'd also buy more components than I needed in case I mess up.

[fly135]

How about one of these? Not sure how well it holds the module as I've never seen one in person.

https://www.aliexpress.com/item/ESP32-t ... 71106.html

John A

[markwj]

How about one of these? Not sure how well it holds the module as I've never seen one in person.

https://www.aliexpress.com/item/ESP32-t ... 71106.html

John A

For prototyping that is just fine - it holds the module in very tightly. But not for production.

[markwj]

Here is an example of a WROOM ....

https://www.ebay.com/itm/ESP32-WROOM-32 ... Sw32lYtNZr

The pinspacings are small (1mm?) but MUCH larger than a raw ESP32 IC.

Here is a mounting board with breadboard sized pin spacings:

https://www.ebay.com/itm/ESP-WROOM-32-E ... gk-iulXHTw

Beyond this, I doubt you'll find pre-soldered WROOM modules on boards.

This is a good solution that I have tried. It really is not too difficult to solder, even without SMD style equipment. I generally don't suggest pre-soldering the pads (as that just tends to lift the module up too high off the board). Easier to just lay it flat, then solder opposite corners in place. Then, one by one handle the rest. Plenty of flux, small amounts of solder, and a normal soldering iron.

The other option is to use an existing devkit, and de-solder the components you don't need (the ones that use the most power).