ESP32 Forum

Just bought a Mac mini M2 to do ESP32 developement and it does not detect ESP32 boards. Mac OS 13.5. Rebuild several times.

Tried 3 seperate ESP32 devices with different cables. All work perfectly on Mac Book Air M2. None work on Mac mini M2.

Does not create the Unix device (ls /dev/*) when connected, interesting power LED comes on.

Tried installing Arduino IDE as well - does not detect the device.

I notice in the "System Settings-> Privacy & Security -> All accessories to connect" does not exist.

Any work arounds?

Finally found a combination of USB A Cable and ESP32 boards that detect on Mac mini M2.

Seems very fussy compared to the Mac Book Air M2.

So, to help others in the future, what were the boards in question and what was the solution?

There are a zillion different ESP32 boards. They're made with varying degrees of competence.

One thing that trips up dev board developers is leaving off the pullup (pulldown?) resistors on CC1 and CC2. This will let the boards 'work' on cases that don't use Apple's exacting standards of USB-C PD compliance. In particular, if you power them from USB-A, they'll work and, ridiculously, if you plug them into a Mac (or Mac-grade USB-C power source), will work only if you route them from USB-C->USB-A (which adds the resistor) adapter and then to a C to C cable. If you reverse this cable - which has "C" on each end" is works in only one direction. Swap the cable end-for-end and it will [ start | quit ] working.

Does your unnamed ESP32 board use USB-C? Do schematics (and visual confirmation) show 5.1K resistors on the CC1 and CC2 lines?

Raspberry Pi famously botched this on the early runs of the 4 boards.

Thank you RandomInternetGuy. This solved my issue. I plugged a cheap C-to-A converter into my Mac Mini M4, plugged an A-to-C cable into it, then the other end into my ESP32S3 custom board, and it worked. Interestingly I never had to do this rigamarole before my Mac Mini auto-updated to Sequoia 15.7.4. Hope this helps some other frustrated soul...

If that weirdo cable "fixed" it, it would have been "broken" (it actually works like they designed the board, which just happens to be "badly" - you don't think I would have just guessed such a crazy configuration, do you? ) on pretty much any Apple USB-C power source or most other better (e.g., not gas station grade power bricks that are USB-A power bricks with a changed connector) grades of name-brand USB-C devices provided by engineering teams that actually read and understand the USB3/USB-C specification and its impact upon power usage. Every Mac and every Apple power supply in my life has worked this way as have name brand devices. Generics pretty consistently get this wrong.

Tip: https://www.adafruit.com/product/6323 is a good thing to keep on hand if you don't have the fortitude to attach the resistors yourself.

The ONE case that CAN be compliant that would be attributed to this is that if this was a board for an ESP32 running in USB host mode (S2, S3, P4) that might be providing power FOR a USB device (keyboard, mouse, disk drive, etc.). In that configuration, it's the USB TARGET, not the HOST, that needs those pull-ups, and they can't be doubled, so they SHOULD be open on the ESP32's host side.

I suspect that about 5% of all such development boards are used in such a configuration, so I choose to believe it was laziness/incompetence where a board developer took a USB-Mini-B configuration and slapped a USB-C connector on it and shipped it OR they consciously saved the cost of two 5.1K resistors, which, in quantity, would be a few pennies. If the developer ACTUALLY cared about USB-C spec compliance, they'd have provided jumpers to bridge power from +5VDC to the USB connector (not everyone wanting to power a USB thingy will want to power it FROM the ESP32 dev board) and open up those two pads, right? Clearly, I hold such hardware in pretty low regard by default.