Problem facing to measure current in nRF51822 MC

[kvrb]

Hi,

I am working with nrf51822 MC. In my Transmitter code, i am using in low power mode. I was enabled the low power in my code (__WFE(), __SEV(), __WFE()). I measuring the current using LED and resistance in series with a multimeter. It is showing around 1.3mA current even in low power mode also it showing the same thing. I put a delay in low power mode so that I can measure current and after low power mode also I put one more 15 sec delay so that I can see a difference in multimeter but I am always getting 1.3mA current.

What I am doing wrong here. I am attaching code with this.

main.c

[Jørgen Kvalvaag]

You cannot use nrf_delay_ms to delay in sleep mode. When nrf_delay_ms() is executing the CPU is running and you should see around 4mA. (not 1.3)

The HFCLK consumes around 500uA, and it is always running in your code. It can be turned off when you are not using the radio/ESB library.

To make better current measurement, you can use the RTC timer to send packets at desired intervals, and call power_manage() from the NRF_ESB_EVENT_TX_SUCCCESS event.