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Confused about GPIO pin usage

PostPosted: Mon Jul 04, 2016 8:20 am
by Jep
Hi,

Something still unclear to me!!!

I currently use ESP12E as a single chip and I need 3 GPIOS (2 as OUTPUTS and 1 as INPUT).
I configured GPIO4 and GPIO5 as OUTPUTS as it seems they are not linked to any other function ...
BUT I don't know which one to use as INPUT! :?
I tried to use GPIO9, GPIO12 with the following line:
Code: Select allpinMode(9, INPUT);

but the Soc does not boot up :!:
According to the picture below, some GPIOs are used for SPI, UART ...
Suppose I'm not using SPI, how can I reassign a SPI pin to a simple GPIO???
I'm afraid I'm completely lost with the way I can use GPIOs! :(
Image

Re: Confused about GPIO pin usage

PostPosted: Mon Jul 04, 2016 11:40 am
by rudy
Don't use GPIO6-11 as they are used for the flash chip that holds the code. Only use the ports on the two sides.

Re: Confused about GPIO pin usage

PostPosted: Mon Jul 04, 2016 12:25 pm
by martinayotte
Also, make sure your have RES/CH_PD pulled up, GPIO15 pulled down, and also GPIO2/GPIO0 pulled up.

Re: Confused about GPIO pin usage

PostPosted: Mon Jul 04, 2016 4:13 pm
by Jep
rudy wrote:Don't use GPIO6-11 as they are used for the flash chip that holds the code. Only use the ports on the two sides.


Hi rudy,
I also tried with GPIO12 which is out of your "not to use" range but I have the same behaviour.
However I don't understand what is the aim of 12E version if I can't use the extra pins ...
Moreover, I read that if flash was in DIO mode and not QIO it would be possible to use GPIO9 and GPIO10, but I don"t know how ...