Mojo no longer working

Hardware
1

I had been successfully using Mojo for a week or two. But it is now returning the response:
{‘err’: ‘you have no mojo {no-mojo}’, ‘milliamp_hours’: 2193.52, ‘crc’: ‘0002:0CCD3A3F’}

I am running ‘version’: ‘notecard-u5-9.1.1’. I have tried switching cables and the Notecarrier-F(v1.3) Qwiic port I was using, as well as making sure it was connected before supplying power to the notecard. The NoteCarrier is getting battery power through Mojo.

I am open to suggestions as to my next move. I can’t really put my finger on exactly when it stopped working. I was using a Notecarrier-X and had everything in a plastic enclosure while testing out hostless gps readings. I did notice logging stopped at that time. Could something have shorted?

Thanks,
Joe

2

Hi @scavoj

Did your Notecarrier power cycle at some stage, without the Mojo connected?

The Notecard checks for a Mojo at startup and if it does not detect it, it assumes it isn’t present. It is not treated as ‘hot swappable’.

Let me know if a power cycle with the Mojo attached, forces it to re-appear again.

Thanks,
Alex

3

Alex,

The answer to your first question is “probably”. I lost track of what I did and didn’t do.

There is the order that I just tried. If this is not correct please let me know.

  1. Plugged the Qwiic into Mojo then into Notecarier-F.
  2. Plugged the Lipo battery into Mojo.
  3. Plugged the Mojo into the Notecarrier-f
  4. Got a flashing red light from the Notecard, and then it went out.
  5. Got a flashing green light from the Notecard.
  6. Plugged the USB into Pi 5.
  7. Plugged the micro-USB end into Notecarrier-F.
  8. Connected through the web page.
  9. Issued {“req”: “card.version”} and received a reply:
    {
    “version”: “notecard-9.1.1.17181”,
    “device”: “dev:351077454560213”,
    “name”: “Blues Wireless Notecard”,
    “sku”: “NOTE-WBGLWT”,
    “ordering_code”: “HB0YT1N0AEAU”,
    “board”: “5.13”,
    “wifi”: true,
    “cell”: true,
    “gps”: true,
    “body”: {
    “org”: “Blues Wireless”,
    “product”: “Notecard”,
    “target”: “u5”,
    “version”: “notecard-u5-9.1.1”,
    “ver_major”: 9,
    “ver_minor”: 1,
    “ver_patch”: 1,
    “ver_build”: 17181,
    “built”: “Apr 15 2025 11:34:37”
    }
    }
  10. Issued a {“req”: “card.power”}
  11. Received Reply:
    {
    “err”: “you have no mojo {no-mojo}”,
    “milliamp_hours”: 2193.523657000001
    }

Thanks,
Joe

4

@scavoj as step 12. can you try issuing a {"req":"card.restart"} and then try {"req": "card.power"} again?

5

Did the card.restart then card.power again with same result:
{
“err”: “you have no mojo {no-mojo}”,
“milliamp_hours”: 2193.523657000001
}

6

@scavoj could you share a photo of how you have everything connected? It sounds like it should be able to find the Mojo but I’m wondering if there’s something to do with how you have everything connected that I’m missing.

Thanks,
Alex

7

IMG_6419
IMG_64191920×2015 245 KB

8

That looks ok to me, but I will note a couple of things:

  1. The QWIIC connector that the Mojo is connected to uses a level shifter to handle differing voltages potentially present on the host (Swan). I’m wondering if this might be related to the problem you are seeing.
  2. When you have been testing this, has the Swan always been connected to the Notecarrier F?
  3. You mention a Pi 5, what role does that play in your testing? Is that how you are accessing the web terminal?

Are you still able to see the Mojo if you return to the Notecarrier X?

Thanks,
Alex

9

Alex,

Wen I connect to Mojo using the Notecarrier-X and the web terminal as you suggested, it works fine.

My Pi5 is just my development machine. And the web terminal on the Pi seems to work fine.

Moji was originally working on the Notecarrier-F. I do have the ATTN dip switch set to ATTN to sleep the Swan (that’s another problem for a different discussion).

Thanks,
Joe

10

Alex,

I wanted to let you know of some of my findings while troubleshooting. I have the Notecard-F running with a battery (no Mojo) and running my CircuitPython code. Everything is running fine. Then I plug a power source into the Notecarrier. Immediately, the CircuitPython code starts throwing exceptions which are logged to the _health_host.qo file. As soon as I unplug the power source from the NoteCarrier, the code starts running fine and location data is logged to the data.qo file with no more exceptions. This behavior is repeatable and consistent. This doesn’t occur while connecting my dev computer to the Swan over USB.

I’m also having trouble putting the Swan to sleep using the ATTN DIP switch (I have a separate post about this).

I’m no hardware engineer, but I’m leaning toward the Notecarrier (…says the software engineer :winking_face_with_tongue:)

Thanks,
Joe

1 Like
11

Alex,

You answered my concerns in my previous post in this thread with a response in another message (Failed to aquire I2C lock while trying to put the Swan to sleep with CircuitPython"). The behavior I was seeing in the above post is no longer an issue. Sorry for the tangent.

As soon as I get some time, I’m going to get working on the Mojo again and will let you know if I still have the problem.

Thanks,
Joe

1 Like
12

Thanks for the update Joe. It can often get difficult to debug issues when many things are moving at once :slight_smile:

Hope all is going well with your project!

Thanks,
Alex