ESP32-S Card Module

ESP32-S Card Module
ESP32-S Card Module

What is this?

This project is the result of a lot of prototyping, using different MCUs and wanting to find a way to get a standard interface to all the devices.

The idea is to eventually create similar card-type MCU breakout boards, with similar pins in the same position on the 2x20p breakout header,

for example, power, i2c bus, reset and flash will always be in the same position on the female header…

Step 2 from here on would be to design a baseboard, that is capable of providing power, as well as access to the various GPIO pins. I am thinking along the way of a PC motherboard style interface, with “slots” at regular intervals. These “slots” will have access to the SPI, and I2C bus, as well as various other GPIO.

Step 3 would be a series of commonly used input and output “cards” that will plug into the “slots”…

If successful, I plan to design various MCU cards, with various different processors, with the obvious criteria that they are 3v powered.

This could result in a very flexible development platform, where it is possible to reuse the base-board and IO “cards” with any one of the various MCU “cards”.

The Schematic

As seen on the schematic, almost all of the ESP32-S’s pins are broken out, with the exception of those used for internal flash. Reset and Flash circuitry is provided on the PCB, as well as on the 2x20pin female header.

It is worth noting that I did not include any UART to USB circuitry on the card. Flashing should be performed with an external USB-to-UART converter. It will however be included in the base-board.

There is also no power supply circuitry onboard. This was also intentional, as the card is intended to be powered from the base-board. It is however perfectly acceptable to power only the card from a suitable 3.3v DC power supply unit through the 3v and gnd pins on the 2x20pin header.

Where can I get my own version of this module?

This module will be exclusively available from PCBWay for the foreseeable future. Click on this link to order your own, and help support a great company that produces very high-quality PCBs for a very affordable price.


This PCB was manufactured at PCBWAY. The Gerber files and BOM, as well as all the schematics, will soon be available as a shared project on their website. If you would like to have PCBWAY manufacture one of your own, designs, or even this particular PCB, you need to do the following…
1) Click on this link
2) Create an account if you have not already got one of your own.
If you use the link above, you will also instantly receive a $5USD coupon, which you can use on your first or any other order later. (Disclaimer: I will earn a small referral fee from PCBWay. This referral fee will not affect the cost of your order, nor will you pay any part thereof.)
3) Once you have gone to their website, and created an account, or login with your existing account,

4) Click on PCB Instant Quote

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7) You can also select whether you want an SMD stencil, or have the board assembled after manufacturing. Please note that the assembly service, as well as the cost of your components, ARE NOT included in the initial quoted price. ( The quote will update depending on what options you select ).

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Then just sit back and wait for your new PCB to be delivered to your door via the shipping company that you have selected during checkout.

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