Hi all, thank you for reading this.
Issue: I’m working with a RAK4600 + RAK5005 baseboard and I’d like to verify the low power mode current draw.
Setup: The baseboard is fed by a USB cable, which I modified so I can put a shunt resistor in series with it. To calculate the current draw I measure the voltage drop over the shunt.
Observation: After boot, I measure about 6mA. As soon as I open the Serial port tool the current draw increases to about 7.8mA. I then send the AT command to put it into sleep, but the measured current draw only drops a little to about 7.2mA. What is happening here?
I read that when a USB cable is connected, the board might draw more power. Is this because of the USB to TTL converter chip? What is the recommended approach of measuring power consumption? I do not have a lipo battery and the datasheet says that the supply voltage on the bat connector may not exceed 4.2V.
Thank you in advance,