ESP32: Some pins are not properly configured

[SergioGasquez]

See errata 3.6, we currently have a fix for this (

esp-hal/esp-hal-common/src/soc/esp32/gpio.rs

Lines 575 to 658 in f315d2b

	pub(crate) fn errata36(pin_num: u8, pull_up: bool, pull_down: bool) {
	use crate::peripherals::RTC_IO;
	let rtcio = unsafe { &*RTC_IO::PTR };
	match pin_num {
	0 => {
	rtcio
	.touch_pad1
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	2 => {
	rtcio
	.touch_pad2
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	4 => {
	rtcio
	.touch_pad0
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	12 => {
	rtcio
	.touch_pad5
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	13 => {
	rtcio
	.touch_pad4
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	14 => {
	rtcio
	.touch_pad6
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	15 => {
	rtcio
	.touch_pad3
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	25 => {
	rtcio.pad_dac1.modify(|r, w| unsafe {
	w.bits(r.bits())
	.pdac1_rue()
	.bit(pull_up)
	.pdac1_rde()
	.bit(pull_down)
	});
	}
	26 => {
	rtcio.pad_dac2.modify(|r, w| unsafe {
	w.bits(r.bits())
	.pdac2_rue()
	.bit(pull_up)
	.pdac2_rde()
	.bit(pull_down)
	});
	}
	27 => {
	rtcio
	.touch_pad7
	.modify(|r, w| unsafe { w.bits(r.bits()).rue().bit(pull_up).rde().bit(pull_down) });
	}
	32 => {
	rtcio.xtal_32k_pad.modify(|r, w| unsafe {
	w.bits(r.bits())
	.x32n_rue()
	.bit(pull_up)
	.x32n_rde()
	.bit(pull_down)
	});
	}
	33 => {
	rtcio.xtal_32k_pad.modify(|r, w| unsafe {
	w.bits(r.bits())
	.x32p_rue()
	.bit(pull_up)
	.x32p_rde()
	.bit(pull_down)
	});
	}
	_ => (),
	}
	}

) but is not always called, e.g. the i2c constructor does not apply this workaround.

[bjoernQ]

Even with ESP-IDF (e.g. with a changed i2c_simple_main.c example) I don't get I2C to work on these pins without external pull-ups

[liebman]

This even fails for simple gpio input with pull up (at least with gpio33). Using the following leaving gpio33 unconnected and it waits for gpio33 top go high - it should be pulled up but it keeps waiting.

#![no_std]
#![no_main]

use esp_backtrace as _;
use esp_println::println;
use hal::{clock::ClockControl, peripherals::Peripherals, prelude::*, Delay, IO};

#[entry]
fn main() -> ! {
    let peripherals = Peripherals::take();
    let system = peripherals.SYSTEM.split();

    let clocks = ClockControl::max(system.clock_control).freeze();

    let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);
    let input = io.pins.gpio33.into_pull_up_input();

    let mut delay = Delay::new(&clocks);

    loop {
        println!("wait for high...");
        while input.is_low().unwrap() {
            delay.delay_ms(10u32);
        }
        println!("wait for low...");
        while input.is_high().unwrap() {
            delay.delay_ms(10u32);
        }
    }
}

[liebman]

I found that for gpio32 and gpio33 they were reversed in the errata36 function. I'll send a PR.
Based on the datasheet:
gpio32 = x32p
gpio33 = x32n

[liebman]

PR added #1053

[SergioGasquez]

Closed by #1053