UART Power Consumption with MODEM

RE: UART Power Consumption with MODEM

Jørgen Holmefjord — Mon, 10 Mar 2025 12:49:39 GMT

You can typically see if the CPU is running or not by looking at the current consumption. The CPU run current is quite static and documented in the current consumption chapter of the product specifications.

There are also exist HW events (EVENTS_SLEEPENTER/EVENTS_SLEEPEXIT) that can be used to toggle GPIOs when entering/exiting sleep (you need to use PPI/GPIOTE for this).

RE: UART Power Consumption with MODEM

QBSho — Fri, 07 Mar 2025 08:42:15 GMT

Hello Jörgen,

i have the same issue and also tried to pu t uart_irq_rx_disable
How could i check if the CPU is in sleep?

RE: UART Power Consumption with MODEM

Jørgen Holmefjord — Thu, 25 Jul 2024 13:10:43 GMT

Hi,

The UART will draw current as long as RX is enabled. UART works asynchronously and the chip needs to keep clocks and other resources active to be able to receive data at anytime when the other side of the line decides to send data.

If you shut down the modem, you should also be able to disable UART RX to save power. Try calling uart_rx_disable() API.

Best regards,
Jørgen