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FONA3G not working other than on USB
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FONA3G not working other than on USB

by mariell81 on Sun Jan 31, 2021 3:00 pm

I am having trouble getting the FONA 3G shield to work in any other way than on USB. When on USB, it works fine, but when trying to connect it directly to a microcontroller, it is dead (not even LEDs blinking). I have tried to power VIO both with 3.3V and 5V, but same result.

Wiring:

VIO <-> 3V3 (or 5V, depending on controller)
GND <-> GND
TXD <-> RXD
RXD <-> TXD
KEY <-> GND

It is my understanding that I should see LEDs lighting up in this case, even if I would just have VIO and GND are connected. Am I doing anything obviously wrong, or are there troubleshooting steps I can follow?

mariell81
 
Posts: 4
Joined: Sun Jan 31, 2021 2:56 pm

Re: FONA3G not working other than on USB

by mikeysklar on Mon Feb 01, 2021 5:20 pm

@mariell81,

Do you have a LiPo battery also plugged in with or without USB?

Can you post a photo of your setup?

mikeysklar
 
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Joined: Mon Aug 01, 2016 8:10 pm

Re: FONA3G not working other than on USB

by mariell81 on Mon Feb 01, 2021 6:32 pm

3g_setup_sm2.jpg
3g_setup_sm2.jpg (486.59 KiB) Viewed 418 times
mikeysklar wrote:@mariell81,

Do you have a LiPo battery also plugged in with or without USB?

Can you post a photo of your setup?


Yes, I am using a LiPo battery, both when connected to USB and when not. I am including a picture of the setup. I hope it is clear, but if you have any questions or would like a close-up of things, feel free to ask.

mariell81
 
Posts: 4
Joined: Sun Jan 31, 2021 2:56 pm

Re: FONA3G not working other than on USB

by mikeysklar on Tue Feb 02, 2021 1:58 pm

Wiring looks good. Thanks for the photo.

Is the LiPo one of our packs? Sometimes the connections are reversed on 3rd party packs and they won't work with our hardware. This would explain why USB works and powering off the LiPo does not.

What size LiPo is it (mAh)?

mikeysklar
 
Posts: 4619
Joined: Mon Aug 01, 2016 8:10 pm

Re: FONA3G not working other than on USB

by mariell81 on Tue Feb 02, 2021 2:48 pm

mikeysklar wrote:Wiring looks good. Thanks for the photo.

Is the LiPo one of our packs? Sometimes the connections are reversed on 3rd party packs and they won't work with our hardware. This would explain why USB works and powering off the LiPo does not.

What size LiPo is it (mAh)?


it is a LiPo I have bought elsewhere (3700 mAh). When reading out the battery status using AT commands, I get a 4-ish volt, which looks good to me. Would it be safe to try to swap the battery connections? It is a connector that only fits one way..

Can you make a close-up picture of the battery connector, with the lock up, so I can compare it to mine?

mariell81
 
Posts: 4
Joined: Sun Jan 31, 2021 2:56 pm

Re: FONA3G not working other than on USB

by mikeysklar on Wed Feb 03, 2021 3:24 pm

Your pack looks like it has a reverse JST compared to the one I'm looking at. This is common. I would recommend using our packs.

lipo.jpg
lipo.jpg (129.17 KiB) Viewed 402 times

mikeysklar
 
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Re: FONA3G not working other than on USB

by mariell81 on Wed Feb 03, 2021 9:28 pm

mikeysklar wrote:Your pack looks like it has a reverse JST compared to the one I'm looking at. This is common. I would recommend using our packs.

lipo.jpg


The battery poles were indeed reversed. After swapping the poles, everything works fine.
Thank you very much!

mariell81
 
Posts: 4
Joined: Sun Jan 31, 2021 2:56 pm

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