ESP32 Forum

Hi there,

i think it should be possible to connect any gpio to another logical gpio.

i use the W1TS and W1TC functions to set and clear the gpio levels.
I have 14 bit values and those values i give out as binary to the gpios.
I do this by clearing all necessary bits with WITC and then calculating the new value with OR and AND and bitshift. Then I set the value .
This all needs time, so i would like to know, if there is a better way.

Could someone tell me, how to logical swap the Pins?
for now i use 4,5,13,14,15,16,17,18,19,21,22,23,26,27 because they are in the same register and not needed to boot.

i do it like this:

uint32_t GPIO_w1ts = GPIO_OUT_W1TS_REG;
uint32_t GPIO_w1tc = GPIO_OUT_W1TC_REG;

uint32_t SetBits (uint16_t bits)
{
return ( (bits & 0b11000000000000)<<14) | ((bits & 0b00111000000000)<<12)|((bits & 00000111111100)<<11) | ((bits & 0b....
}

main:

int counter=1;
while(1)
{
count++;
GPIO_w1tc=0b1100111011111110000000110000; //clear em all
GPIO_w1ts= SetBits(counter);
}
///////////////////////////////////////////////////////////////

Now i would like to use another gpio setting, that i could do the following:

GPIO_w1ts = counter;

You see, i would like to swap the numbers of the logical connected pins.

Also I would like to know, if there is a way to set a value without resetting the register.

Sorry for my bad english!

Sorry, the hardware doesn't really have any tricks you can do here... I fear that your implementation is pretty optimal already. The bitshifts shouldn't take too much time, however; the Xtensa architecture has dedicated instructions for that. If you really want something faster, you can try spending some memory on a lookup table in RAM to go from counter value to GPIO-mask; that makes the runtime conversion into just a lookup in that table.

Thank you ESP_Sprite!

Somehow my first post disappeared after correcting some words. So I repost it again with some added text::

/////////////->->->
Hi there,

i think it should be possible to connect any gpio to another logical gpio.

i use the W1TS and W1TC functions to set and clear the gpio levels.
I have 14 bit values and those values i give out as binary to the gpios.
I do this by clearing all necessary bits with WITC and then calculating the new value with OR and AND and bitshift. Then I set the value .
This all needs time, so i would like to know, if there is a better way.

Could someone tell me, how to logical swap the Pins?
for now i use 4,5,13,14,15,16,17,18,19,21,22,23,26,27 because they are in the same register and not needed to boot.

i do it like this:

uint32_t* GPIO_w1ts = GPIO_OUT_W1TS_REG;
uint32_t* GPIO_w1tc = GPIO_OUT_W1TC_REG;

uint32_t SetBits (uint16_t bits)
{
return ( (bits & 0b11000000000000)<<14) | ((bits & 0b00111000000000)<<12)|((bits & 00000111111100)<<11) | ((bits & 0b....
}

main:

int counter=0;
while(1)
{
counter++;
*GPIO_w1tc=0b1100111011111110000000110000; //clear em all
*GPIO_w1ts= SetBits(counter);
}
///////////////////////////////////////////////////////////////

Now i would like to use another gpio setting, that i could do the following:

GPIO_w1ts = counter;

You see, i would like to swap the numbers of the logical connected pins.

Also I would like to know, if there is a way to set a value without resetting the register.

I have now figured out, that there is also a register that can be used to direct communicate with the output pins.

it seems, that if i only write a value in a
///////////////////////////////////////
uint32_t* GPIO_w1t = GPIO_OUT_REG;
while(1)
{
*GPIO_w1t = 0b1100111011111110000000110000;
}
///////////////////////////////////////
i get an output.


this blink-code is also working:
///////////////////////////////////////
uint32_t* GPIO_w1t = GPIO_OUT_REG;
while(1)
{
*GPIO_w1t = 0b1100111011111110000000110000;
vTaskDelay(1000 / portTICK_RATE_MS);
*GPIO_w1t = 0
vTaskDelay(1000 / portTICK_RATE_MS);
}
///////////////////////////////////////

,...but when i try to measure the output frequency by doing:
///////////////////////////////////////
uint32_t* GPIO_w1t = GPIO_OUT_REG;
while(1)
{
*GPIO_w1t = 0b1100111011111110000000110000;
*GPIO_w1t = 0;
}
///////////////////////////////////////
every output-pins stays 0V,...

i think, that using GPIO_OUT_REG could save the µc some time, but somehow it seems a bit tricky.
it seems to be "not atomic" as people call it.
I could not figure out, if the "not atomic" behavior means what i see on my desc.
Thought it would mean, that it needs not always the same amount of time.
Could someone explain me please?

Now i do it like
////////////////
*GPIO_w1tc = 0b1100111011111110000000110000 & (~(BitShiftedValue));
*GPIO_w1ts = BitShiftedValue;
///////////////


Sorry for my bad english!