Hey jhox616

jhox616 Can you help me figure out why this happened?

I’d be happy to. I also replied to your email. Here’s my reply for your reference:

I was not getting satellites in view of the sky where I have gotten a fix before on other devices.

Were you outside or inside?

I was reading the serial output and it just wouldn’t get a fix. I left it for a long time thinking that it needed to download the almanac.

You may need to download/enable use of the SUPL client. Though you should get a fix even without it though..

On plugging in the battery it smoked the board. I can’t see exactly where but it looks like one of the ICs shorted.
My thought was that this board could be powered and read the serial at the same time.
I am hoping for your advice on why this happened.
I’m not sure if it is a malfunction in the board or what.

You need to be careful not to reverse polarities of the battery. Can you share how you made your connections. Pictures would be helpful.

        jaredwolff oh course. It is entirely possible that the polarity was switched. It uses the small JC plug type (i know that that isn’t correct but I hope you know what I’m trying to say) so it is s male/female slotted connection. I will show you the color wires and orientation so you can tell me if the polarity on the battery connector is not oriented the same as the board. Once that is isolated as the issue. I’d be happy to buycanother board and try again. But until I know exactly what went wrong there is no use smoking another $120 board. I really appreciate everything you do: your product, your service, and the extra mile you go in helping the community. Hopefully this can just be a lesson learned and I can continue on in success with your board. It has been very discouraging but I’m hoping in the end it will be worth it.

            Yea unfortunately you’re not the only person to fry the charger chip due to reverse polarity. I will likely have to add protection in the next versions. Fortunately, as long as your board didn’t get too toasty it’s likely salvageable.

            jhox616 $120 board

            Should be $99. I don’t charge more than that. 😃

            If you want to save some $ you can ship it to me and I’ll see if I can revive it for a small fee.

                Ok I just want to make sure that was the exact issue so I will get back to you with pictures.

                  5 days later

                  jaredwolff

                  I sent you the pics via email.
                  Let me know so I can make sure it doesn’t happen again.
                  A new feather with antennas is only $120 so why would the repair be $99?
                  Once you help me figure out the polarity issue I will probably order a few more but I was hoping I could get it repaired cheaper than that.
                  Thanks again for your help.

                      jhox616

                      I replied to your email. Here’s the image you provided of your battery cell:

                      See my response copied below. Look carefully of which side is the positive and which side is the negative on that JST connector:

                      Also take a look at this page for example: https://www.adafruit.com/?q=lithium+&sort=BestMatch

                      Look closely at the orientation of black/red. They’re opposite to the battery you used. That’s no bueno and definitely no supported.

                      It’s easy to fix on that battery if you want. You just need something sharp like a pin to remove each wire and then push them into the correct orientation.

                          Also in response to your earlier comment:

                          jhox616 A new feather with antennas is only $120 so why would the repair be $99?

                          I think you misunderstood me. I was simply clarifying my boards cost $99. (Not $120) The repair would be much less as long as it’s something I can repair. It’s hard to tell the extent of the damage since the picture you sent earlier was a bit blurred.

                              jaredwolff
                              Ok that all sounds great. I will respond to your email and get your address to mail it to you.
                              I’ll probably have you mail it back if you can fix it with another one I’ll buy. Thanks for everything. I’ll double check all my batteries.

                                8 days later

                                Does the GPS need battery power to opporate?
                                I could not aquire satellites or a fix with it being powered via the serial port alone.

                                  If you check the schematic, the “power path” from battery or USB is the same.
                                  I’m not sure, what you exactly do. Simplified, GPS is used in two modes, “classic” and “assisted”. For “classic”, the GPS receiver starts with receiving “broad-banded”, which isn’t that sensitive. Therefore you need “free sight to the sky”. Once the receiver detect the first signals, it switches to “smaller-banded” mode, which is much more sensitive and may work with less “free sight to the sky”, at least for something about 3h. In the “assisted” mode, the data received in the “broad-banded” phase are exchanged via the cellular protocol and with that, GPS is able to start “smaller-banded”.

                                  That results in:
                                  “classic” requires “initial free sky” and if the device is connected indoor with USB, that doesn’t work
                                  “assisted” doesn’t required that “initial free sky” and may therefore work in less good conditions.

                                    jhox616 Does the GPS need battery power to opporate?

                                    You do not but if your power source is noisy you may not get a fix as fast. Also someone else in the community is having issues with GPS. I’m going to double check to make sure I didn’t break the sample.

                                        jhox616 what sample were you using? The gps sample was missing a config variable which was preventing the GPS antenna from being powered properly.

                                        Here is the correct nfed/samples/gps/boards/circuitdojo_feather_nrf9160_ns.conf

                                        #
# Copyright (c) 2021 Circuit Dojo LLC
#
# SPDX-License-Identifier: Apache-2.0
#

# GPS Antenna configuration
CONFIG_MODEM_ANTENNA=y
CONFIG_MODEM_ANTENNA_AT_COEX0="AT\%XCOEX0=1,1,1565,1586"

# Enable Zephyr application to be booted by MCUboot
CONFIG_BOOTLOADER_MCUBOOT=y

                                            Ah, maybe that is why it wasn’t working. It was just the gps test sample under nfed.

                                              2 months later

                                              jaredwolff

                                              I updated the board config info.
                                              Is the GPS example suppose to give feedback over serial?
                                              When I connect over serial it just just says “connected over COM4!”
                                              After I was expecting information on satellites it is acquiring or something…

                                                  It should. Make sure you’re connected to the right port and you’re using the latest SDK.

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