RTC Running in System ON Mode Current Consumption?

[starkAbhi]

hi,

i am using nrf connect extension in vs code with Zephyr os version v3.2.99-ncs2 , 

when device in system on sleep how much current consume by nrf52833 development kit ? when only RTC Being on.

1. during sleep, RTC  current consumption?

2. what is complete current consumption flow(rtc,idle thread and LFRC) during system on sleep? 

pm_state_force(0u, &(struct pm_state_info){PM_STATE_SUSPEND_TO_IDLE, 0, 0}); //nrfonly switch 

[Karl Ylvisaker]

Hello,

For information about the power consumption in these different scenarios please take a look at the Electrical Specification in the Product Specification.

Best regards,
Karl

[starkAbhi]

hi,

i have read the electrical specification. i want to know during system in sleep. in which nrf52833 dk consume only 2.2 uA. so which peripheral are on in the sleep. rtc+lfrtc+ram retention = 2.2uA?? or how can i lower the current consumption in sleep. less than 2uA like 1.6uA something?

[starkAbhi]

hi,

Karl Ylvisaker said:

We do unfortunately not have any examples that match this description already, but it should not take you so long to set this up yourself. I would suggest that you start out with one of the minimal BLE example, such as the Multiple Advertising Sets sample, trim away the extra advertising sets, and implement the go-to-sleep and wake-from-sleep procedures (turning off/on peripherals and RAM, etc.).

i have some experience with nrf connect vscode sdk. i need only some guidance on API to put device in sleep to minimize sleep current near to 1.6uA or less.

below code i used to advertise-sleep-periodically.

//advertiser sleep

#include <zephyr/types.h>
#include <stddef.h>
#include <zephyr/sys/util.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
//---power management lib--
#include <zephyr/pm/pm.h>
#include <zephyr/pm/device.h>
/////////////////////////////

#define DEVICE_NAME CONFIG_BT_DEVICE_NAME
#define DEVICE_NAME_LEN (sizeof(DEVICE_NAME) - 1)

uint8_t vol_Per = 0; //voltage in % but hex converter it

static uint8_t adv_data[] = {
0x0f,0x18, //uuid battery service uuid[1],uuid[0] //0x180f: battery services
0x10 //data: battery percentage hex to % 0x10 = 16%
};

static const struct bt_data ad[] = {
BT_DATA_BYTES(BT_DATA_FLAGS, BT_LE_AD_NO_BREDR),
BT_DATA(BT_DATA_SVC_DATA16,adv_data,3),   
};

/* Set Name adv data */
static const struct bt_data sd[] = {
BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
};

static void bt_ready(int err) {
	char addr_s[BT_ADDR_LE_STR_LEN];
	bt_addr_le_t addr = {0};
	size_t count = 1;
	/* Start advertising */
	bt_le_adv_start(BT_LE_ADV_NCONN_IDENTITY, ad, ARRAY_SIZE(ad), sd, ARRAY_SIZE(sd));

	bt_id_get(&addr, &count);
	bt_addr_le_to_str(&addr, addr_s, sizeof(addr_s));
	// printk("Beacon started, advertising as %s\n", addr_s);
}

void main(void) {
/* Initialize the Bluetooth Subsystem */
bt_enable(NULL);
while(1) {
bt_ready(0); //advertising
/* Update advertising */
//// -------simulating voltage increasing gradually-----------
// vol_Per++;
// adv_data[2] = vol_Per;
// if (vol_Per > 64) {
// vol_Per = 0;
// }
// k_sleep(K_SECONDS(1)); //1 second
// //////////////////////////////////////////////////////
// bt_le_adv_update_data(ad, ARRAY_SIZE(ad),sd, ARRAY_SIZE(sd));

k_sleep(K_SECONDS(1)); //WAIT time
bt_le_adv_stop();
pm_state_force(0u, &(struct pm_state_info){PM_STATE_SUSPEND_TO_IDLE, 0, 0}); //nrfonly switch: 2.2 uA 
k_sleep(K_SECONDS(3)); //update time
} //end of while
}//end of main

Karl Ylvisaker said:

If you are not yet familiar with the nRF Connect SDK then I would highly recommend taking a look through the DevAcademy Fundementals course to quickly familiarize with the SDK.

thanks for sharing , i already have seen it. 

[Karl Ylvisaker]

Hello,

starkAbhi said:

thanks for sharing , i already have seen it. 

I am glad to hear that! :) 

Looking at the code you have shared you really should check the returned error codes from your SDK function calls - if you do not then you will have no way to know whether the call completed successfully or failed for whatever reason.

You will also need to explicitly disable your RAM before going to sleep, which will require your to re-configure and initialize your application when you wake from sleep (because the contents of the RAM will be wiped).

Best regards,
Karl

[starkAbhi]

Hi,

My apologies for late reply, could you please suggest me code snippet or example to disable RAM. and enable it again. what is the most power efficient techniques to increase the battery life?

[Karl Ylvisaker]

Hello,

starkAbhi said:

My apologies for late reply

No problem at all - we continue this whenever you get the chance :) 

starkAbhi said:

could you please suggest me code snippet or example to disable RAM. and enable it again.

You can set which RAM blocks will be retained and which will not as described in the documentation I referenced below, please give this a try and let me know if you run into any issues - then you can share the code snippets from what you attempted and what you were trying to achieve, then we can take a look and guide you to how you could achieve it.

starkAbhi said:

what is the most power efficient techniques to increase the battery life?

Shutting down everything that you do not need during sleep is a good start, but there are other things you can do as well. You should also take a look at this blogpost for a introduction to power optimization of nRF52 series SoCs.
Have you started work on the hardware design, with regards to your power circuitry and configuration?

Best regards,
Karl

[starkAbhi]

Hi,

Karl Ylvisaker said:

You can set which RAM blocks will be retained and which will not as described in the documentation I referenced below, please give this a try and let me know if you run into any issues - then you can share the code snippets from what you attempted and what you were trying to achieve, then we can take a look and guide you to how you could achieve it.

i used this way to get System on sleep. which API /Function need to call to put device in RAM OFF Sleep?

//advertiser sleep

#include <zephyr/types.h>
#include <stddef.h>
#include <zephyr/sys/util.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
//---power management lib--
#include <zephyr/pm/pm.h>
#include <zephyr/pm/device.h>
/////////////////////////////

#define DEVICE_NAME CONFIG_BT_DEVICE_NAME
#define DEVICE_NAME_LEN (sizeof(DEVICE_NAME) - 1)

uint8_t vol_Per = 0; //voltage in % but hex converter it

static uint8_t adv_data[] = {
0x0f,0x18, //uuid battery service uuid[1],uuid[0] //0x180f: battery services
0x10 //data: battery percentage hex to % 0x10 = 16%
};

static const struct bt_data ad[] = {
BT_DATA_BYTES(BT_DATA_FLAGS, BT_LE_AD_NO_BREDR),
BT_DATA(BT_DATA_SVC_DATA16,adv_data,3),   
};

/* Set Name adv data */
static const struct bt_data sd[] = {
BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
};

static void bt_ready(int err) {
	char addr_s[BT_ADDR_LE_STR_LEN];
	bt_addr_le_t addr = {0};
	size_t count = 1;
	/* Start advertising */
	bt_le_adv_start(BT_LE_ADV_NCONN_IDENTITY, ad, ARRAY_SIZE(ad), sd, ARRAY_SIZE(sd));

	bt_id_get(&addr, &count);
	bt_addr_le_to_str(&addr, addr_s, sizeof(addr_s));
	// printk("Beacon started, advertising as %s\n", addr_s);
}

void main(void) {
/* Initialize the Bluetooth Subsystem */
bt_enable(NULL);
while(1) {
bt_ready(0); //advertising
k_sleep(K_SECONDS(1)); //WAIT time
bt_le_adv_stop();
pm_state_force(0u, &(struct pm_state_info){PM_STATE_SUSPEND_TO_IDLE, 0, 0}); //nrfonly switch: 2.2 uA 
k_sleep(K_SECONDS(3)); //update time
} //end of while
}//end of main

Karl Ylvisaker said:

Shutting down everything that you do not need during sleep is a good start, but there are other things you can do as well. You should also take a look at this blogpost for a introduction to power optimization of nRF52 series SoCs.

yes, I followed the Given instructions. are there any power management Example Code on nrf connect for vscode zephyr ncs to clear Concepts? 

Karl Ylvisaker said:

Have you started work on the hardware design, with regards to your power circuitry and configuration?

currently, our hardware contain nRF52833 standalone which is directly connected to 3v button cell. our goal to achieve minimum current consumption tracker device nearly ~ 1 uA. Current  consumption is majorly depend upon Application Software Flow. could you please suggest us any external hardware configuration?  

[Edvin]

Hello,

Karl is out of office, so I am sorry for the late reply. 

I don't know what current consumption you currently are looking at, but you can check what my colleague answered in a similar question yesterday, regarding how to control the RAM retention.

It also holds the table containing current consumption in different states.

Best regards,

Edvin

[starkAbhi]

Hi Edvin,

Edvin said:

I don't know what current consumption you currently are looking at, but you can check what my colleague answered in a similar question yesterday, regarding how to control the RAM retention.

My application requirement is to advertise data then go to  sleep periodically . it has to consume  ~1.2uA current in sleep. due to less power consumption connected battery has long life. we able to achieve 2.2 uA  in sleep by using given code above. how to decrease the current consumption more to close 1uA.

previously "Karl' asked about hardware design. in response we are open to suggestions. could you please us in hardware design?

Regards Abhishek

[Edvin]

Hello Abhishek,

For HW review, please create a new ticket where you include the schematics and layout files, and request a HW review. You can also mention that you are looking to reduce the current consumption so that they know what to look for. 

I can only see some snippets from your application, so I don't know what is enabled or not, and what you have connected to your board. Do you use any external devices powered by the nRF? Sensors? And did you disable the UART logging, e.g. by setting CONFIG_SERIAL=n in your prj.conf?

BR,
Edvin

[Edvin]

And regarding your measured current consumption. Based on your comment, I believe I understand it correctly, but the 2.2µA is the current while you are in sleep, right? So it is not an average while you are advertising as well?

BR,
Edvin

[starkAbhi]

Hi Edvin,

Edvin said:

For HW review, please create a new ticket where you include the schematics and layout files, and request a HW review. You can also mention that you are looking to reduce the current consumption so that they know what to look for. 

okay, i will create another ticket.

Edvin said:

I can only see some snippets from your application, so I don't know what is enabled or not, and what you have connected to your board. Do you use any external devices powered by the nRF? Sensors? And did you disable the UART logging, e.g. by setting CONFIG_SERIAL=n in your prj.conf?

all peripherals are disabled. only i am using ble for advertisement. currently i am using nrf52833 dk . yes, i disabled the uart logging.

Regards Abhishek Tiwari