High current consumption after waking up from deep sleep state (LoRa NVRAM example)

[Adnan Sabovic]

Hi everyone,

I am working with fipy board where I am trying to implement LoRa. In my case the current consumption of the board is very important and because of that I have already included this option of deep sleep state after each LoRa transmission. The main problem is the high current consumption after fipy wakes up and tries to send the data again. I included NVRAM features because I wanted to prevent the board to start the initialization over and over again, but still based on the output from the power analyzer the current peaks are very high. Can you maybe suggest me how to decrease the current or avoid this behavior?

Thanks in advance!
Br,
Adnan.

[jcaron]

@Adnan-Sabovic can you let us know the current levels you are observing, and for how long? If you have a graph even better.

Do you use LTE or WiFi at all? What firmware version are you using?

[Adnan Sabovic]

In my case, I just use LoRa NVRAM example that I found on your website where my device goes to the deep sleep state and stays there until the next transmission is ready. I do not use LTE or WiFi, or any other supported technology except LoRaWAN. About firmware I am not sure, I started with fipy board experiments before 1-2 weeks. I send you the photo where you can see the behavior of the device. I expected to get a bit lower current consumption and not super high peaks after waking up from deep sleep.

[livius]

@Adnan-Sabovic
Better if you paste image into your message (it will be uploaded to the server)

[Adnan Sabovic]

@livius is now better?

[d.alvrzx]

@Adnan-Sabovic I have never observed current consumption of my LoPy4 devices with such detail, but the values you are getting seem in line with typical consumption for these boards. I would also say the peaks are normal for board initialization and transmission. Note that the highest peak of 0.57 A lasts maybe 1 ms from what I can see in your image, so it won't affect your current consumption drastically.

From the FiPy datasheet, average current consumption for the board with no radios is 62.6 mA @ 5V. You are averaging 100 mA (although I do not know what voltage you are using), so maybe your WLAN module is on. Make sure to turn it off by setting the pycom.wifi_on_boot() flag to False or by manually disabling it via WLAN().deinit(). Since this is a FiPy, make sure the LTE modem is powered off, as well as Bluetooth and Sigfox (although these are usually off by default).