Reducing power consumption when sd card is unmounted

RE: Reducing power consumption when sd card is unmounted

Sigurd — Mon, 01 Jul 2024 10:51:41 GMT

Any logs would be useful here, in order to debug this further. If possible, also a small simple project that reproduce the issue.

RE: Reducing power consumption when sd card is unmounted

control — Thu, 20 Jun 2024 08:28:34 GMT

Sorry, I did not express myself correctly. I just observed that some voltage appears on the MISO pin but I did not solve the problem.

RE: Reducing power consumption when sd card is unmounted

Sigurd — Wed, 19 Jun 2024 13:59:08 GMT

[quote user="control"]I measured voltages on SPI pins and observed when the SD card was unmounted, it was still sending data to the NRF chip via the MISO pin which was the cause of the problem.[/quote]

Were you able to fix this? Sounds like something went wrong with the unmount.

RE: Reducing power consumption when sd card is unmounted

control — Wed, 19 Jun 2024 07:41:22 GMT

I do not have special logs. Both mentioned functions return 0. I measured voltages on SPI pins and observed when the SD card was unmounted, it was still sending data to the NRF chip via the MISO pin which was the cause of the problem. If the SD card is removed and plugged in again, the power consumption is reduced to the expected value.

RE: Reducing power consumption when sd card is unmounted

Sigurd — Tue, 18 Jun 2024 14:21:46 GMT

Hi!

[quote user="control"]

When sd_card_close_file is called the power consumption does not decrease to the initial value but starts even increasing.

[/quote]

Do you have any logs from this?

Did pm_device_runtime_put(spi0_device) return 0 ?

What does pm_device_runtime_is_enabled(spi0_device) return ?

RE: Reducing power consumption when sd card is unmounted

control — Tue, 11 Jun 2024 08:36:49 GMT

I try to implement your suggestion by using device runtime API. Here is my overlay file:

&spi0 {

    compatible = "nordic,nrf-spi";  
    status = "okay";
   
    pinctrl-0 = <&spi0_default>;
    pinctrl-1 = <&spi0_sleep>;
    pinctrl-names = "default", "sleep";   
    cs-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>,
               <&gpio1 6 GPIO_ACTIVE_LOW>,
               <&gpio0 12 GPIO_ACTIVE_LOW>,
               <&gpio0 15 GPIO_ACTIVE_LOW>;
   
   ...
    sdhc0: sdhc@3 {        
        compatible = "zephyr,sdhc-spi-slot";
        reg = <3>;
        status = "okay";
       
        mmc {
            compatible = "zephyr,sdmmc-disk";
            status = "okay";
        };
        spi-max-frequency = <1000000>;
    };    
};

in sd_card.h I have the following define:

#define SPI0_DEVICE_ID  DT_NODELABEL(spi0)

and in sd_card.c

struct device* spi0_device = DEVICE_DT_GET(SPI0_DEVICE_ID);
bool sd_card_ctor(void)
{

 return pm_device_runtime_enable(spi0_device) == 0;
}
void sd_card_init(void)
{  
    if(pm_device_runtime_get(spi0_device) == 0)
        printk("OK PM\n");

    int res = fs_mount(&mp);    

    if (res == FR_OK)
    {      
        printk("Disk mounted.\n");
        fs_file_t_init(&fs_file);      
    }
    else
    {
        printk("Error mounting disk.\n");        
    }
}

void sd_card_close_file(void)
{
    int res = fs_close(&fs_file);

    if (res == FR_OK)
    {
        //printk("FS close.\n");        
    }
    else
    {
        printk("FS close error\n");        
    }

    res = fs_unmount(&mp);  

    if (res == FR_OK)
    {
        printk("Disk unmounted.\n");        
           
    }
    else
    {
        printk("Error unmounting disk.\n");        
    }
   
   
    if(pm_device_runtime_put(spi0_device) == 0)
        printk("OK PM\n");
}

When sd_card_close_file is called the power consumption does not decrease to the initial value but starts even increasing.

I do not know what I am doing wrong. I would appreciate any help.

RE: Reducing power consumption when sd card is unmounted

Sigurd — Mon, 10 Jun 2024 09:30:48 GMT

Hi!

Maybe you could try to use the device power management API, and suspend the SPI

https://docs.zephyrproject.org/latest/services/pm/device.html