Esp32 core v3 compiles and uploads non-functioning binary

[vnp85]

Board

ESP32 dev modules, most every board I have

Device Description

Physical board: many kinds of ESP32s, some modern, some older. It worked with a more recent camera module dev board, but failed with the Heltec oled wifi boards / analogous. These boards have the CP2102 implementation, USB-to-UART programming method. I didn't try with boards that feature native USB.

Hardware Configuration

Nothing custom, all boards made and available in bulk, that have worked previously right out of the box.

Version

v3.1.3

IDE Name

Arduino IDE

Operating System

win 11

Flash frequency

tried with both 40 and 80

PSRAM enabled

no

Upload speed

115200 default

Description

Nutshell version: source code, both complex custom code, then a simple custom hello world serial printf code and even the provided blinky example, and physical boards that used to work, all of a sudden fail silently on a fresh arduino install, and I traced the issue to having esp32 core v3 instead of core v2 that's been on another machine I used to successfully program the same boards with the same source code, blinky, hello world.

Setup: new computer, fresh Arduino install, esp32 core (v3) grabbed from the board manager.
Board selection from many: against many types, in particular Devkit v1, WROOM etc -- boards that I remembered were working.

Bug: compile anything, my own code, the provided blinky from the examples: no issue. Upload: no issue. Run? Nothing beyond the bootloader, no blink, no serial port, no guru crash core dump, just total silence. Sometimes I did see some garbage in the serial, sometimes it even looked like the wrong baudrate with the right timing, but overall I couldn't consistently reproduce the behavior, nor see anything meaningful with the logic analyzer, it just looked like garbage, or, more often, nothing at all.

Switching back, manually, to ESP32 core v2: everything works, like it used to.

Somewhat similar to #9802 and what it links to, though still confused about the behavior of silent failure, of not inspecting the bootloader's output for potential incompatibilites etc. This is the reason I come to open the issue: the failure's nature.

PS: last time I came, it was for a muted compiler warning that was perhaps turned into an error, for the code that it produced did crash the firmware on the spot (non-void function has no return value), which happened, I guess, due to changing the calling convention or something, unrelated.

Sketch

- stock blinky
- three liner hello world over serial
- complex custom firmware

Debug Message

:: emptystring

Other Steps to Reproduce

hello world over serial:

have core v3 to fail,
have core v2 to succeed

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[lbernstone]

I am going to guess this is on devices with a 26MHz crystal, which is no longer supported in the default configuration. You can check the crystal rate with esptool chip_id (you can also see this on upload if you set that to verbose in preferences). I can't remember exactly which incantations you need to do to get 26MHz, but read through #9837

[vnp85]

@lbernstone your guess is correct, the board in question has the 26MHz crystal.

while another board that, did work, features a 40MHz crystal.

Yes, this information solves the particular issue itself, but the root cause remains:

• the entire appeal of Arduino is/was that I don't do the XTAL-PCLK-HOCO-LOCO voodoo manually, especially since the coupling of particular boards and config to a generic arduino source code is rough terrain.
• the boards in question are not some obscure custom devices that have never worked in the past, quite the opposite
• the fact that for stock code and widely available devices that used to work / still work / the failure is silent, is what's particularly bothersome.

Anyway: let's hope that others googling for these symptoms will find this post and proceed accordingly.

Thank you.

[lbernstone]

The heltec_wifi_kit_32 and heltec_wifi_lora_32 have F_XTAL_MHZ set.

[vnp85]

You are right there. As I mentioned, my goto board selection is/was "Devkit v1, WROOM etc", perhaps my bad, as these were the settings that worked with the boards I have, WROOM, WROVER dev boards and capsule modules without the breakout board, Heltec variants, etc. And still work with core v2.

https://github.com/espressif/arduino-esp32/blob/master/variants/doitESP32devkitV1/pins_arduino.h