Power consumption of ncs1.9.0 SDK

[duxinglang]

I used 9160 to develop a product for the customer. Previously, I used ncs1.2.0 SDK, and the power consumption of the whole machine was about 200uA. Now I am going to use ncs1.9.0 SDK, but after migrating to the new platform, I found that the power consumption of the whole machine has increased significantly, reaching 1.85ma. Why?

Both firmware use the modem firmware of V1.3.1. The difference is that I sleep UART in ncs1.2.0, but I do not see such operation in ncs1.9.0.

[Øivind]

Hi,

Can you try enabling CONFIG_PM_DEVICE?

This enables the device power management feature in Zephyr.

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/pm/device.html

[duxinglang]

Thank you. I used this function to wake up and Hibernate the UART according to your reminder. Now the power consumption of my device has been reduced. However, there seems to be a small problem, that is, it seems to take a long time to wake up the UART after hibernation, which may cause a part of the data transmitted through the UART to be lost.

This is my code for uart control:

void uart_sleep_out(void)
{
#ifdef CONFIG_PM_DEVICE
	if(k_timer_remaining_get(&uart_sleep_in_timer) > 0)
		k_timer_stop(&uart_sleep_in_timer);
	k_timer_start(&uart_sleep_in_timer, K_SECONDS(UART_WAKE_HOLD_TIME_SEC), K_NO_WAIT);

	if(uart_is_waked)
		return;
	
	pm_device_action_run(uart_ble, PM_DEVICE_ACTION_RESUME);
	k_sleep(K_MSEC(10));
	
	uart_is_waked = true;

#ifdef UART_DEBUG
	LOGD("uart set active success!");
#endif
#endif
}

void uart_sleep_in(void)
{
#ifdef CONFIG_PM_DEVICE
	if(!uart_is_waked)
		return;
	
	pm_device_action_run(uart_ble, PM_DEVICE_ACTION_SUSPEND);
	k_sleep(K_MSEC(10));
	
	uart_is_waked = false;

#ifdef UART_DEBUG
	LOGD("uart set low power success!");
#endif
#endif
}

[Øivind]

Can you try enabling hw-flow-control?
Add 

hw-flow-control;

to the uart0 node in your overlay file.