ESP32-S2 doesn't work at 400 kHz: it operates at 5 kHz (reviving issue #8480)

[dzalf]

Board

ESP32-S2

Device Description

Custom ESP32-S2 (based on Lolin S2 Mini Wemos

Hardware Configuration

Two ESP32-S2 boards connected by I2C

Version

latest stable Release (if not listed below)

Type

Bug

IDE Name

VSCode + pio

Operating System

Windows 11

Flash frequency

80 Mhz

PSRAM enabled

yes

Upload speed

921600

Description

Hey, guys. I come here to revive issue #8480.

I am trying to communicate two ESP32-S2 boards at 400 kHz, and it's the same story: it goes down to 5kHz

I tried the solution from @me-no-dev , however, it doesn't do much ( too old perhaps?)

I modified these lines:

/**
 * @brief  Init I2C master
 *
 * @param  hw Beginning address of the peripheral registers
 *
 * @return None
 */
static inline void i2c_ll_master_init(i2c_dev_t *hw)
{
 typeof(hw->ctr) ctrl_reg;
    uint32_t ref_always_on = ctrl_reg.ref_always_on;
    ctrl_reg.val = 0;
    ctrl_reg.ms_mode = 1;
    ctrl_reg.sda_force_out = 1;
    ctrl_reg.scl_force_out = 1;
    ctrl_reg.ref_always_on = ref_always_on;
    hw->ctr.val = ctrl_reg.val;
}

However, the system still reverts to 5kHz

I am working with Platformio under the Espressif 32 6.12.0

Any ideas?

Sketch

constexpr int SDA_PIN = 4; // GPIO4 for SDA
constexpr int SCL_PIN = 2; // GPIO2 for SCL

i2c_Link->setPins(SDA_PIN, SCL_PIN);
i2c_Link->begin();
    
i2c_Link->setClock(400000UL); 

}

Debug Message

I am unable to print the Core debug message with my current system. I am using USBCDC native USB

Other Steps to Reproduce

No response

I have checked existing issues, online documentation and the Troubleshooting Guide

• I confirm I have checked existing issues, online documentation and Troubleshooting guide.

[me-no-dev]

@dzalf I suggest you switch to pioarduino. PlatformIO is stuck on core 2.0.17 that is not supported from a long time, while pioarduino is at the latest core 3.3.4

[dzalf]

@me-no-dev Thank you for the prompt response.

Could you please point me to the latest documentation where I can see the latest Core used by PlatformIO?

I installed pioarduino, and after restarting VSCode I cleaned my project, build and flash my board again and the I2C Clock is still running at 5 kHz where I configured 400 kHz

What am I missing?

Thanks!

🍻

[dzalf]

@me-no-dev apologies, I figured it out myself:

Then, I used the line:

platform = https://github.com/pioarduino/platform-espressif32/releases/download/stable/platform-espressif32.zip

in my project.

Now, I am having additional issues where my code used the GPIO accessors for pin manipulation:

static void fastGpioSet(uint8_t gpio)
{
    if (gpio < 32)
        GPIO.out_w1ts = (1 << gpio);
    else
        GPIO.out1_w1ts.val = (1 << (gpio - 32));
}

...sigh

However, the GPIO object doesn't seem to exist on the new Core

EDIT:

I keep finding solutions after asking more questions here:

I used the latest implementation for the newest core:

void Link::_fastGpioSet(uint8_t gpio)
{
    gpio_set_level((gpio_num_t)gpio, 1);
}

void Link::_fastGpioClear(uint8_t gpio)
{
    gpio_set_level((gpio_num_t)gpio, 0);
}

bool Link::_fastGpioRead(uint8_t gpio)
{
    return gpio_get_level((gpio_num_t)gpio);
}

Now, I managed to get both systems running on pioarduino using the latest core after updating my entire project.

UNFORTUNATELY, the latest core ONLY works at 100 kHz!

If I set this on my master ESP32-S2:

   i2c_Link->setPins(SDA_PIN, SCL_PIN);
    i2c_Link->begin();
    i2c_Link->setClock(I2C_CLOCK_STANDARD); // e.g. 400 kHz defined in pinout.h scope

where I2C_CLOCK_STANDARD is set at 100000

my code runs fine and I can see SCL pulsing at 100 kHz:

However, if I change the Clock speed to 400000 there is NO COMMUNICATION whatsoever. The I2C Bus is dead dead

[me-no-dev]

However, if I change the Clock speed to 400000 there is NO COMMUNICATION whatsoever. The I2C Bus is dead dead

this is not our experience. Please provide minimal reproducible code to confirm

[dzalf]

@me-no-dev I am preparing a new issue. I cannot get the clock from the I2C bus to operate above 100 kHz