I2C/TWIM doesn't work properly on nRF54H20DK

Question

Hi,

we have nRF54H20DK (SoC rev. "C"). connected to MAX77655 via I2C (SCL ~ P1.0, SDA ~ P1.4 according to I2C restriction).

I am trying to test i2c131 for reading/writing data but I can only transfer the first byte (I2C Maxim IC address = 0x44). The other bytes seem to be random and do not depend on the input parameters of the I2C function.

I want to send 3 bytes, but without success.

value "ret" != 0

SDK: v2.9.0-nRF54H20-rc1

IDE: VSCode + nRF Connect plugin

PC: Windows 11 Pro

hardware: nRF54H20DK

I aware of this note in documentation: "[19] Only SPI master and UART will be supported for the initial limited sampling. " Is this right? Is there any workaround?

Thanks.

code fragment

#define MAX77655_I2C_ADR 0x44

uint8_t i2c_tx_buffer[] = { 4, 7, 1 };

	if(device_is_ready(dev_i2c_ptr)) {
		int config_result = false;
		printk("I2C master device IS ready!\n");
//		 config_result = i2c_configure(dev_i2c_ptr, I2C_SPEED_SET(I2C_SPEED_STANDARD) | I2C_MODE_CONTROLLER );		// I2C_MODE_MASTER
	}
	else {
		printk("I2C master device not ready!\n");
	}


    ret = i2c_write(dev_i2c_ptr, i2c_tx_buffer, sizeof(i2c_tx_buffer), MAX77655_I2C_ADR);

Kconfig

prj.cfg

CONFIG_GPIO=y
CONFIG_I2C=y

Overlay

&i2c131 {
    compatible = "nordic,nrf-twim";
    status = "okay";
    pinctrl-1 = <&i2c131_sleep>;
    pinctrl-0 = <&i2c131_default>;
    pinctrl-names = "default", "sleep";
    clock-frequency = <I2C_BITRATE_STANDARD>;
};

&pinctrl {
    i2c131_default: i2c131_default {
        group1 {
            psels = <NRF_PSEL(TWIM_SCL, 1, 0)>,     // SCK signal must be at pin 0..3 in each port. These pins cannot be used for other SPIS signals.
                    <NRF_PSEL(TWIM_SDA, 1, 4)>;
            bias-pull-up;                           // bias only in this power mode
        };
    };

    i2c131_sleep: i2c131_sleep {
        group1 {
            psels = <NRF_PSEL(TWIM_SCL, 1, 0)>,     // SCK signal must be at pin 0..3 in each port. These pins cannot be used for other SPIS signals.
                    <NRF_PSEL(TWIM_SDA, 1, 4)>;
            low-power-enable;
        };
    };
};

I2C master write issue (sizeof sending data = 3)

Source code: TWI_USB.ZIP

Jennifer Gibbs · Accepted Answer

Hello Peter,

I was speaking with Arvind this afternoon and he pointed me to this case so we could assist. Could you try adding the following to your &i2c131 overlay:

memory-regions = <&cpuapp_dma_region>;

Similar to this example:

arduino_i2c: &i2c130 {

compatible = "nordic,nrf-twim";

pinctrl-0 = <&i2c130_default>;

pinctrl-1 = <&i2c130_sleep>;

pinctrl-names = "default", "sleep";

clock-frequency = <I2C_BITRATE_STANDARD>;

zephyr,concat-buf-size = <255>;

memory-regions = <&cpuapp_dma_region>;

};

Let me know if that works for you.

Thank you,

Jennifer Gibbs

Peter Langer Keysoft · Answer

Many thanks for this fix. It works now.

&i2c131 {
    compatible = "nordic,nrf-twim";
    status = "okay";
    pinctrl-0 = <&i2c131_default>;
    pinctrl-1 = <&i2c131_sleep>;
    pinctrl-names = "default", "sleep";
    clock-frequency = <I2C_BITRATE_STANDARD>;
    zephyr,concat-buf-size = <255>;
    memory-regions = <&cpuapp_dma_region>;

    max77655_lbl: max77655@44 {
//                compatible = "maxim,max77655";
                compatible = "i2c-device";
                reg = <0x44>;       // MAX77655 I2C Address 0x44 - Perform all (0x40, 0x44, 0x48, 0x52) reads and writes on the Main Address. 
                                            // The ADDR is a factory one-time programmable (OTP) option. (max77655.pdf page 44 table 7)
                label = "MAX77655";
    };
};

BR

I2C/TWIM doesn't work properly on nRF54H20DK

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