ESP8266 Community Forum

Posted: **Thu Apr 07, 2016 7:52 am**

Hi everyone, i'm new here,
i got my ESP8266 yesterday and i already started playing with it on Arduino IDE.
After testing some wifi examples, i went through hardware benchmarking,
i'm now able to set and clear a single GPIO with these instructions, (example on GPIO2):

Code: Select all

    GPOS = 1<<2;
    GPOC = 1<<2;

that i found in the "core_esp8266_wiring_digital.c" file.
Now i need to manipulate multiple GPIOs at the same time,
(read or write the entire port in only one instruction).
I tryed GPOP, ex:

Code: Select all

    GPOP = GPOP | 0x00000004;
    GPOP = GPOP & 0xFFFFFFFB;

but obviously it gives me "'GPOP' was not declared in this scope".
Anyone know the proper register name?
Thank you

Posted: **Thu Apr 07, 2016 9:24 am**

if you look in hardware/esp8266/2.1.0/cores/esp8266/esp8266_peri.h, you will see the following defines :

Code: Select all

#define GPO    ESP8266_REG(0x300) //GPIO_OUT R/W (Output Level)
#define GPOS   ESP8266_REG(0x304) //GPIO_OUT_SET WO
#define GPOC   ESP8266_REG(0x308) //GPIO_OUT_CLR WO
#define GPOP(p) ((GPO & (1 << ((p) & 0xF))) != 0)

Posted: **Thu Apr 07, 2016 3:53 pm**

Thank you, i got it working with these instructions:

Code: Select all

    GPO = GPO | 0x00000004;
    GPO = GPO & 0xFFFFFFFB;

But something strange is happening,
it seems to have a sort of interrupt every about 3 seconds that delays the execution and sends some ramdon data through USART.
the instruction

Code: Select all noInterrupts();

in the setup makes only the delay shorter but it is still there.
Do you know anything about it?

Posted: **Thu Apr 07, 2016 4:43 pm**

Thank you, i got it working with these instructions:

Code: Select all

    GPO = GPO | 0x00000004;
    GPO = GPO & 0xFFFFFFFB;

But something strange is happening,
it seems to have a sort of interrupt every about 3 seconds that delays the execution and sends some ramdon data through USART.
the instruction

Code: Select all noInterrupts();

in the setup makes only the delay shorter but it is still there.
Do you know anything about it?

ESP8266 Community Forum

Direct GPIO port register manipulation

Direct GPIO port register manipulation

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