gpio 10 doesn't work with new board 2.4.2 on Arduino IDE

[claudiofrancesconi]

hello i am trying to use gpio 10 as an output on a nodemcu esp8266-12e with Arduino IDE
it used to work like charm when i used the board 2.4.1, after i upgraded to 2.4.2 it's not working anymore.

Any tips?

[devyte]

Pins 9 and 10 aren't available on 8266 devices, unless you modify the board to cut the pcb lines and, then change the flash mode to not use those lines. Is that what you're doing?
Or do you have some special board?

[claudiofrancesconi]

as i said with board 2.4.1 worked like charm

[torntrousers]

It did used to work: #2124 (comment). I haven't tried it recently though.

[devyte]

And on most 8266 boards using those GPIO with releases prior to 2.4.2 could potentially fry the pins. Or the flash.
You didn't answer my question: what is your specific use case? Did you modify the board by cutting the lines as explained in the above link, or do you have a special board, or something else?

I seem to remember you can still have access to them, but you are now required to change your board settings to one of the generic boards, I don't remember which (generic 8285 maybe?). Alternatively, you have to manually init those pins yourself in the same way the other pins are inited on bootup.

[torntrousers]

The NodeMCU 1.0 is defined to use DIO mode - https://github.com/esp8266/Arduino/blob/master/boards.txt#L2354 - so you can (at least used to) just be able to use GPIO10 without and mod's anywhere.

[claudiofrancesconi]

And on most 8266 boards using those GPIO with releases prior to 2.4.2 could potentially fry the pins. Or the flash.
You didn't answer my question: what is your specific use case? Did you modify the board by cutting the lines as explained in the above link, or do you have a special board, or something else?

I seem to remember you can still have access to them, but you are now required to change your board settings to one of the generic boards, I don't remember which (generic 8285 maybe?). Alternatively, you have to manually init those pins yourself in the same way the other pins are inited on bootup.

as i told you
i didn't change anything
just uploaded the sketch with Arduino IDE and board 2.4.1... i use the pin 10 with TONE command to play a buzzer

[Pablo2048]

You can try to check SPI flash mode - probably you have DIO in previous version of IDE and QIO in 2.4.2...

[devyte]

@claudiofrancesconi I understand that you didn't change anything on your end. I'm telling you that some things related to the init of pins 9 and 10 changed in the core with release 2.4.2, because it was deemed dangerous or nonsensical to leave them as they were for the general use case of the specific boards involved.

Example of nonsensical: init pin as output, write LOW, try to read flash => crash.
Example of dangerous: same as above, but flash pin fries instead of just the ESP crashing.

That's why I asked whether you modified your ESP12e-based Nodemcu when you started using it with 2.4.1 to allow generic use of GPIO 9/10.
See e.g.: this schematic for an ESP12e that shows GPIO 9 and 10 are physically connected to the flash.

If you didn't modify your board, then maybe you were lucky (some flash chips have short protection) or there is some special board case that needs to be tested and allow the pins for the variants involved.

[d-a-v]

gpio 9 and 10 have been recently set to usable only in DOUT mode with esp8285 (by @earlephilhower after he rewrote the whole PWM/Tone code).
@claudiofrancesconi,

• is your board esp8285 based ?
• is it an esp8266 in DOUT mode with gpio9&10 not connected to the flash chip ?

In those case, could you try with latest git version ?
Otherwise, we need to understand your setup.

[torntrousers]

@devyte do you happen to have the PR to hand that did that change? Doesn't an ESP8266 using DIO mean GPIO 9 and 10 are available and so should be useable with ESP8266/Arduino?

[d-a-v]

@torntrousers I'm digging looking for it right now

[d-a-v]

It's #5055. Gpio9&10 are now allowed only with esp8285 (previously always disabled) (that's after 2.4.2).
Changes are needed to allow them in DOUT mode for esp8266 wired like esp8285 with gpio9&10 routed to users.

[torntrousers]

Interesting. #5055 doesn't have any explanation for why it was changed to disallow using GPIO10 with an ESP8266 in DIO mode. It certainly did used to work ok and didn't 'fry' anything, as per this issue and #2124.

[d-a-v]

It changed because @earlephilhower rewrote the whole PWM/tone thing (it was buggy at some point), and ommitted gpio9&10 in the first place, because they are flash pins, not commonly available. Then someone asked why gpio9&10 were gone. The rest of the story is #5055.

[torntrousers]

I think its a regression. There aren't a lot of GPIO's on an ESP8266 so to unnecessarily prevent GPIO10 from being useable seems a shame.