ESP32 Forum

I change the i2c scanner program (from https://github.com/nkolban/esp32-snippe ... cscanner.c) 's I2C pin map. And connect SDA & SCL to 18,19.


Then,it still works without any error.


As a result,I can not map the i2c pins to whatever I want.....

What's wrong?

Are you sure you correctly re-flashed the code? I used I2C a while ago and I'm pretty sure I did not use pin 18 and 19. Can you try to do a `make erase_flash` and reflash?

ysw0145 wrote:I change the i2c scanner program (from https://github.com/nkolban/esp32-snippe ... cscanner.c) 's I2C pin map.

Code: Select all

	i2c_config_t conf;
	conf.mode = I2C_MODE_MASTER;
[b]	conf.sda_io_num = 25;
	conf.scl_io_num = 27;[/b]
	conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
	conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
	conf.master.clk_speed = 100000;
	

And connect SDA & SCL to 18,19.

Then,it still works without any error.
As a result,I can not map the i2c pins to whatever I want.....

What's wrong?

first: why you set up the pins 25, 27 directly and not use the nice define for it
second,
like jeroen mentioned, make clean -
cause looks like if you do this: "but" you connect

SDA & SCL to 18,19.

and your hardware runs without problem with this setup ( connected on 18,19 )

then it looks like you work with "old" .o and .a file for your main or what ever you do
on code with I2C, with a preview compile on 18,19 and your project was not updated.

if you work in eclipes example
be sure you "save your changes on the .c file where you make this change
example by STRG + S
then compile.

if you forget this, then it compiles too, but your changes on the code was not updated.

FYI: if you change a file in eclipse, there is a * in begin of file name
like this:

your file is up2date you did a change on it - if you compile - this change is not supported in the compilation save your changes first - then compile
and use the define for the pins
you never need change then in the main and on each other place if you work
moretimes on this pins, simple then change only in the top of the file
and on one and only place.

hope this helps
best wishes
rudi

I saved the .c files.
Oh......... make clean .

It works.
Thank you.

Good to hear it works! But in theory, unless you did weird things that mess with the modification date of your files, you shouldn't have to run 'make clean' in order for esp-idf to pick up on this change. If you run into issues that get fixed when you run 'make clean' more often, and you manage to reproduce them, I'd highly advise you to create an issue on Github so we can fix that.