Going from the dev board to manufacturing

[arao23]

Excuse me for the rudimentary questions, I'm totally new to this. I've got a functioning project and I'd like to manufacture it.

1) What components will I need to go from a dev board to my own PCB? ESP32 module, a 3V3 LiPo battery, what else? Someone mentioned flash memory?

2) How would I flash the chips with my app? I can't be connecting thousands of chips to my Windows computer via UART to be running "make app-flash", there's gotta be a better way (not to mention that the PCB wouldn't have any circuitry for UART or whatever, short of ripping the chip off the board).

3) Are there any companies that can do this for me?

Thanks

[kolban]

For general guidance on manufacturing electronics devices and services/support to get you going on that, I'd suggest a google search of "how to manufacture electronics". I didn't know and when I googled that I found there were lots of great resources out there.

[arao23]

Thanks I've looked at quite a few resources, so I have a basic understanding of the PCB making process (working on a gerber file at the moment for a SMD-based PCB), the assembly house requirements, etc., but I'm still unsure what components the ESP32 itself needs.

Someone mentioned external flash memory, crystals, etc? Is there a "bill of materials" for it somewhere?

[ESP_Sprite]

It depends... if you use the ESP-WROOM32 modules, most you need is something (LDO, buck converter, ...) to generate a stable power supply that is in range of the module; a LiIon battery can hit 4.2V when charging, which is too much for the module. If you use the ESP32 separately, I suggest you look at the schematic/BOM of the ESP-WROOM32.

For programming: the WROOM32 indeed is easiest to program over serial. The usual way manufacturing goes is that you manufacture a PCB, populate it, then test it to see if every component works as intended. This is usually done using a test jig with pogo pins, and test points on the PCB to match those. If you're building the test jig and software that goes along with it, it's pretty easy to also incorporate a call to esptool.py to flash the module.

If you don't use a module but a separate ESP32, another option is to order the flash chip preprogrammed; there are companies who do that.

[Paladin]

I can help you with this. I've got a product development team.

[arao23]

It depends... if you use the ESP-WROOM32 modules, most you need is something (LDO, buck converter, ...) to generate a stable power supply that is in range of the module; a LiIon battery can hit 4.2V when charging, which is too much for the module. If you use the ESP32 separately, I suggest you look at the schematic/BOM of the ESP-WROOM32.

For programming: the WROOM32 indeed is easiest to program over serial. The usual way manufacturing goes is that you manufacture a PCB, populate it, then test it to see if every component works as intended. This is usually done using a test jig with pogo pins, and test points on the PCB to match those. If you're building the test jig and software that goes along with it, it's pretty easy to also incorporate a call to esptool.py to flash the module.

If you don't use a module but a separate ESP32, another option is to order the flash chip preprogrammed; there are companies who do that.

You're the best, that helps a lot! I looked at the BOM of the WROOM32 and there are a LOT of materials in it (at least for my eyes). Is there a simpler sample schematic with the bare minimum components necessary to get it working, or is the WROOM32 it?

That's cool, is there a sample out there that shows how to setup the test jig and pogo pins on a Gerber file?

[arao23]

I can help you with this. I've got a product development team.

Cool, how do I contact you in case I can't figure it out myself?

[WiFive]

Wroom-32 is pretty minimal

19 capacitors
2 ICs
1 crystal
1 resistor
1 inductor

[arao23]

Gotcha. If I use the WROOM 32 then for simplicity, how do you set up your test jig? I assume I'd need to make a pogobed that I can insert the PCB into, with pads on the board that connect to the appropriate pins on the module so that I can flash it. Anybody have sample Gerber data for this?

[dgurau]

I've got a similar problem.
My "production" board is ESP32 bare module and to upload the firmware I'm using "ESP32-WROVER Development Board Test Burning Fixture Tool"