There is no pin 18 on the Sparkfun Pro Mini ESP32

Development Boards ESP32
1

I’ve gone through the “Technical Support Live Forums” but found no solutions. The issue is with the Debug pins MTCK, MTDI, MTDO and MTMS and the pins they map to on the board
MTMS: Maps to pin 18 ——–> But there is no pin 18 on this board!
MTDI: Maps to pin 19
MTCK: maps to pin 20
MTDO: Maps to pin 21

The above pin settings can be found in datasheet

on page 11

What alternative board pin can I use?

Alternatively, can I assign a pin so it maps to MTMS? If so, what pin would you recommend?

And how do I do this through software?

2

Hi @jbspfn ,

I think you’re getting the package pin and GPIO numbering mixed up?

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The numbers around the board edge are GPIO numbers. You need GPIO 14, 12, 13 and 15.

14, 13 and 15 are available. 15 is Qwiic SDA. But sadly 12 is not broken out…

Why didn’t we make 12 accessible? Space on that board is limited and GPIO 12 is a bootloader strapping pin. We put it - and the other strapping pins - low on the list of pins-to-break-out.

Sorry!

There are other ESP32 PICO MINI boards out there that do have 14, 12, 13 and 15 accessible. The ESP32-PICO-DEVKITM-2 is one example.

I hope this helps,
Paul

3

Thanks, Paul, for the clarification on the pins, I am new to esp32. Now I know that they correspond to GPIO numbers. I will consider buying the devkit later but for now I really wanted a dual core board, and I believe I bought one already from Sparkfun (SparkFun Thing Plus - ESP32 WROOM (USB-C) ). It will do for now. The jtag pins are only accessible through ESP-IDF and that’s ok, it will be a good learning experience.