How to set an interrupt on LDSW via GPIO in the NPM1300 using the nRF Connect SDK.

[Priyesh Shahi]

I am using NCS v2.5.1 and working on a project where I need to turn off the system using a button that triggers an interrupt on a GPIO. I want this GPIO to control a load switch to turn it on and off. Where both the GPIO and the load switch are part of the NPM1300. How can I achieve this using the nRF Connect SDK?

Is there any configuration available in overlay file? 

[Sigurd Hellesvik]

Hi,

From Product specification Load switches/LDO regulators:

"The load switches are OFF by default and can be controlled through a control register or GPIO pin using the following bits."

Regards,
Sigurd Hellesvik

[Priyesh Shahi]

Hi Sigurd,

Thank you for the information regarding the control of load switches/LDO regulators through a control register or GPIO pin.

I was wondering if it’s possible to implement these changes (controlling the load switches) directly via the overlay file in NCS, without modifying the source code. Specifically, I'm looking to set the control through a GPIO pin using the overlay file configuration.

Any guidance on this would be greatly appreciated.

Regards,

Priyesh shahi

[Robin M Saltnes]

Hi, yes this is possible.

You have to add
enable-gpios = <&npm1300_ek_gpio 0 GPIO_ACTIVE_HIGH>; 
to the load swtich/LDO settings portion of your overlay.

You also have to add the gpio controller in the i2c configuration portion of the overlay. 

example:

&arduino_i2c {
   npm1300_ek_pmic: pmic@6b {
       compatible = "nordic,npm1300";
       reg = <0x6b>;

       npm1300_ek_gpio: gpio-controller {
           compatible = "nordic,npm1300-gpio";
           gpio-controller;
           #gpio-cells = <2>;
           ngpios = <5>;
       };

};

npm1300_ek_ldo1: LDO1 {
    regulator-initial-mode = <NPM1300_LDSW_MODE_LDSW>;
    // soft-start-microamp = <20000>;
    enable-gpios = <&npm1300_ek_gpio 0 GPIO_ACTIVE_HIGH>;
    
};

[Priyesh Shahi]

Hi,

I tried the approach you suggested by adding enable-gpios = <&npm1300_ek_gpio 0 GPIO_ACTIVE_HIGH>; to the load switch/LDO settings portion of my overlay. I also included the GPIO controller in the I2C configuration section as you advised.

However, it didn't work as expected. Below is the code I tried:

&i2c0_default {
	group1 {
		bias-pull-up;
	};
};

&arduino_i2c {
    npm1300_ek_pmic: pmic@6b {
        compatible = "nordic,npm1300";
        reg = <0x6b>;
 
        npm1300_ek_gpio: gpio-controller {
            compatible = "nordic,npm1300-gpio";
            gpio-controller;
            #gpio-cells = <2>;
            ngpios = <5>;
        };


		npm1300_ek_regulators: regulators {
			compatible = "nordic,npm1300-regulator";

            npm1300_ek_ldo1: LDO1 {
				regulator-init-microvolt = <3300000>;
				regulator-allowed-modes = <NPM1300_LDSW_MODE_LDSW>;
                regulator-initial-mode = <NPM1300_LDSW_MODE_LDSW>;
                // soft-start-microamp = <20000>;
                enable-gpios = <&npm1300_ek_gpio 3 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;             
            };
		};
         
    };    
 };

Additionally, I found in one of the DT binding files that to make the enable-gpios property work, we might need to set the DVS (Dynamic Voltage Scaling) mode first.

Could you please advise on the next steps? Should we configure the DVS mode before enabling the GPIO, or is there something else that might be missing?

Thanks for your help!

[Sigurd Hellesvik]

I see that the nPM1300 One Button sample has not been mentioned in this ticket yet.

Maybe this sample does what you need?

[Priyesh Shahi]

The code snippet I provided earlier is actually from that same sample, but unfortunately, it's not working as expected in my case.

I want to configure one of the nPM1300 GPIOs to trigger the load switch. 

[Sigurd Hellesvik]

I am talking with our experts here, and they ask:

"
Can you confirm customer has connected something at LSIN* inputs? Also it seems they want to use the LDO mode, but they are configuring it as LDSW ( regulator-initial-mode = <NPM1300_LDSW_MODE_LDSW>; )."

[Priyesh Shahi]

We are using the buck converter's output at the LSIN* input, and in this ticket, I was advised to use LDSW mode.

Robin M Saltnes said:

You have to add
enable-gpios = <&npm1300_ek_gpio 0 GPIO_ACTIVE_HIGH>; 
to the load swtich/LDO settings portion of your overlay.

You also have to add the gpio controller in the i2c configuration portion of the overlay. 

example:

look into the code snippet provided in the conversation above.

[Robin M Saltnes]

Is I2C communcation working correctly in your appliaction? If there is no communication any settings from overlays will not be applied to the nPM1300 on startup...   It is also important that the "nPM Controller" USB is NOT connected when you're using the EK with a DK, as that will interfere the I2C communications. 

PS: telling you how to do something you asked for how to do is not the same as advising you to do it. 

[Priyesh Shahi]

I2C communication is working correctly in my application because I am able to see the voltage and other data coming from the PMIC.

In the NPM1300 product specification page, I found information about the load switch mode, which I previously asked for help in configuring via the overlay file.

Sigurd Hellesvik said:

From Product specification Load switches/LDO regulators:

"The load switches are OFF by default and can be controlled through a control register or GPIO pin using the following bits."