Sleep Power Consumption

LPWAN Modules / EVBs RAK4600
1

I am testing the RAK4600 module and have some questions about the power consumption.

When the board is first powered on it consumes about 290uA

When I join the LoRaWAN network using OTAA it then uses 2.89mA after joining

I then put the device to sleep with the command at+set_config=device:sleep:1 and the current only drops to 2.48mA. If I don’t join the network first then the current actually goes up when the device is put to sleep!

The specification says a sleep current of 2.0uA. How do I achieve this?

The firmware version is 3.0.0.8 and I am using an Otii ARC to measure the current consumption

2

How did you send the command, can you show the picture of your test?

3

I am sending the commands via the Otii UART interface to UART2 on the board.

As you can see from the pictures the module responds to the sleep command but the current consumption goes up if you haven’t joined or only very slightly down if you have. It is nowhere near the advertised value.

Sleep without join
Sleep without join1295×1241 43 KB

4

Sleep after join
Sleep after join1295×1241 44.5 KB

6

dd88739de3ba23486e9e7537732c2872a6388481
dd88739de3ba23486e9e7537732c2872a63884813024×4032 3.22 MB

7

It is recommended that you use bluetooth to send, or sleep after removing the UART serial port connection.
By the way, you can modulate the voltage to 2.0V.

8

So I can only use bluetooth to put the device to sleep?
That is not much good if I want to use an external MCU to send data.

When I send the same command to a RAK4200 module the current drops to around the expected level. I think there is a firmware issue with the RAK4600.

9

No, when you send at commands through uART serial port, the UART serial port may affect the power consumption of the module.