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  • Modems exhibiting different behavior

One thing that I’ve seen cause that is if you’re not using the external NOR flash you should initialize it. Also I’ve had good results initializing the wp and hold GPIOs separately:

/ {
    zephyr,user {
        latch-en-gpios = <&gpio0 31 GPIO_ACTIVE_HIGH>;
        wp-gpios = < &gpio0 8 GPIO_ACTIVE_LOW >;
        hold-gpios = < &gpio0 10 GPIO_ACTIVE_LOW >;
    };

&spi3 {
	w25q32jv: w25q32jv@0 {
        /delete-property/ wp-gpios;
        /delete-property/ hold-gpios;
		t-enter-dpd = < 3500 >;
		t-exit-dpd = < 3500 >;
	};
};
static int setup_gpio(void)
{
	gpio_pin_configure_dt(&wp, GPIO_INPUT | GPIO_PULL_UP);
	gpio_pin_configure_dt(&hold, GPIO_INPUT | GPIO_PULL_UP);

	return 0;
}

piotr337 Also, if none of the GPIO pins are connected, does it make sense to set them to either pull-up/down so they aren’t left floating?

The on-reset default should be fine for most pins.

    Keysight 34450A

    I have no experience with such high speed multimeter. But “190 readings/sec” is much slower then I run my power profiler. So, not sure, if that value fits the reality. A simple Nordic Power Profiler Kit II is quite inexpensive (around 100 Euro). There are a couple of power charts of the nRF9160 in the web, I also published some one, see zephyr-coaps-client / power-consumption

    Would that be PSM sleep?

    The modem has several function to save energy (mainly by switching between the 3 states faster). If you switch the modem off/on (CFUN=0/CFUN=1) the switching on takes some more energy. If you network supports PSM, then the device will be able to enter the sleepmode and wakeup faster (and with less energy). In general, people report, that the difference is quite large. In my own experience with the nRF9160 both works very close to each other.
    If you want to know more about the “state” the modem is actually using, there are events which indicates RRC active, RRC ide, sleeping on and sleeping off.

      Nordic’s power profiler is great for budget projects but the Joulescope, in my experience, has a significantly higher sample rate which is useful for catching transients

        JS220

        2 million times per second with 300 kHz bandwidth.

        PPK II

        100 ksps sampling rate

        Anyway, a PPK II does a better job than a high speed multimeter with 190 sps.
        It would be very interesting, if the higher sample rate really does an even better job. Did you made some test comparing that?
        In my experience I use even less samples. I have even tested an “on device” approach with an INA233 at about 1ksps, which results also in pretty good values (about 10% delta to PPK II, but measured “continuously in the wild”).

          AchimKraus Anyway, a PPK II does a better job than a high speed multimeter with 190 sps.

          Yes!

          AchimKraus It would be very interesting, if the higher sample rate really does an even better job. Did you made some test comparing that?

          It sure does. I’ve done side by side tests because one of my customers was saying the current draw was higher than I saw on the PPKII. Ran the test on the Joulescope and sure enough he was right!

              Hey guys. I appreciate all the support. I got sidetracked with a different project for a little bit but now I’m back.

              I have a PPK2, I’ve used it for measuring the draw during development.

              For this I was just using my bench DMM because I just cared about what was going on at idle. So I didn’t think I needed to get the PPK out for that.

              Well the good news is that after adding what Jared recommended to my overlay I was able to get the current draw down a bit more. Will have to measure again but it seemed better then previously.

              The bad board is still reporting approx 4 mA during idle. So I’m not sure what’s going on there still.

              I have a bunch of modems I need to test, so I’ll see how often I get modems idling at higher current.

              Another odd thing happened is that there is one board that I can’t flash anymore.

              I can get it into programming mode and it’s showing up in Linux but when I try to program it, it’s stuck at 0%. I tried this on another computer and same problem.

              Any thought on what could be causing an issue with not being able to program a board?

                AchimKraus

                Thanks for that tip. I need to take a look for that API and see if it’s going into the expected sleep mode.

                I’m pretty sure PSM is working for us based on the activity when measuring via PPK.

                  piotr337 Any thought on what could be causing an issue with not being able to program a board?

                  Did you have the serial monitor open at the same time. That will cause issues with bootloader usage. Is the blue LED solid when running the load command?

                      jaredwolff
                      Yep, it’s solid blue. That’s how I thought it was in flash mode.

                      No serial monitor open.

                      [248274.080979] usb 1-2: new full-speed USB device number 12 using xhci_hcd
                      [248274.231611] usb 1-2: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00
                      [248274.231621] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
                      [248274.231625] usb 1-2: Product: CP2102N USB to UART Bridge Controller
                      [248274.231627] usb 1-2: Manufacturer: Silicon Labs
                      [248274.231630] usb 1-2: SerialNumber: 4e7e73a21a47ec119773ddde461fcfc8
                      [248274.258998] usbcore: registered new interface driver usbserial_generic
                      [248274.259009] usbserial: USB Serial support registered for generic
                      [248274.260192] usbcore: registered new interface driver cp210x
                      [248274.260199] usbserial: USB Serial support registered for cp210x
                      [248274.260222] cp210x 1-2:1.0: cp210x converter detected
                      [248274.261868] usb 1-2: cp210x converter now attached to ttyUSB0
                      (base) piotr@m90q:~$ newtmgr -c serial image upload ~/app_update.bin
                      0 B / 105.95 KiB [--------------------------------------------------------------------------------------------] 0.00%Error: NMP timeout
                      (base) piotr@m90q:~$

                          piotr337
                          (base) piotr@m90q:~$ newtmgr -c serial image upload ~/app_update.bin
                          105.95 KiB / 105.95 KiB [======================================================================] 100.00% 16.28 KiB/s 6s
                          Done
                          (base) piotr@m90q:~$ newtmgr -c serial image upload ~/app_update.bin
                          [-----------------------------------------------------------------------------------------------------] 0.00%Error: NMP timeout
                          (base) piotr@m90q:~$

                          I ran a quick test with a different board, and that worked, then I switched back the “bad” board and it fails.

                          So I don’t think it’s a problem with my setup, because other boards work.

                              I loaded my newest batch of modems and used the same SIM card, antenna, power supply and I get the following results when the modem is at idle.
                              The power supply is running at 3.7 VDC

                              100, 300 µA
                              101, 56 µA
                              102, 122 µA
                              103, 179 µA
                              104, 31 µA
                              105, 14 µA
                              106, 240 µA
                              107, 132 µA
                              And those values are consistent over reboots.

                              SilasValera what firmware are you running? Still your application firmware? What are the values if you run at 3.5VDC on VBAT? I assume the first numbers are the identifiers for the boards?

                              piotr337 I ran a quick test with a different board, and that worked, then I switched back the “bad” board and it fails.

                              Gotcha thanks for checking. Are you strictly using the bootloader only? Is it possible you may have overwritten the bootloader?

                              I believe the default configuration for the newer boards is reverse the polarity that it should be for >= v5. Meaning that if you initialize the LED without those changes it’s on by default. i.e. that may not be the bootloader running but another application

                                    jaredwolff

                                    jaredwolff what firmware are you running? Still your application firmware? What are the values if you run at 3.5VDC on VBAT? I assume the first numbers are the identifiers for the boards?

                                    Yep, still my own application firmware.
                                    Yep, that’s a serial number I’m using to keep track of the boards.
                                    I’ll re-run @ 3.5 VDC on VBAT.

                                    jaredwolff Gotcha thanks for checking. Are you strictly using the bootloader only? Is it possible you may have overwritten the bootloader?
                                    Yep, only flashing via newtmsg application. So if overwritting the bootloader is possible that way then maybe? But it appears to be loading and running the firmware application as normal. So I don’t know about that.

                                    I get the blinking yellow LED, and then the blue steady LED, so that appears normal.

                                            Yea if you’re only using the bootloader via the onboard USB-C then that’s likely not it. Has that board been modified at all? (Headers soldered, etc)

                                              piotr337 I’ll re-run @ 3.5 VDC on VBAT.

                                              I tried 2 modems and they appear to have the same idle current whether on 3.5VDC or 3.7VDC using the battery connector.

                                              I’ll work to test the other boards.

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