Minimal circuit for notecard

What is the minimal circuit needed for the notecard?

Some context: I spun my own PCB for the notecard and I am trying to troubleshoot the design. I am able to create and add notes but the modem does not connect to the cellular network.

I am trying to troubleshoot this problem. Here are my current connections:

I would like to know the minimal circuit needed for the notecard. This would help me determine if I am missing something or a bad solder.


Hello @yamanoorsai,

I’m interested to see the Gerber file for the layer that the M.2 connector is on.
Can you show it?


Pat Jackson

Do you want to see just the layer on which the connector is located? I am no PCB design expert. Any feedback is welcome.


Actually, if you could upload or show all layers… even better.
How did you make your board?


It is a two-layer board that I designed with Eagle. It turns out my repo is private and it is a bit of a headache to make it public.

I am including snapshot from the gerber viewer and the actual PCB

Hey @yamanoorsai I will pass this along to the hardware team to take a look and we will get back to you soon.

BTW, love the Pico Notecarrier! :smiley:

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Thanks. The antenna is missing from the picture but I did use an antenna for my test.

Hi @yamanoorsai, you’re basic schematic looks sufficient - it supplies VMODEM, VIO, and I2C communication. You’ve clearly got it wired correctly since you’re able to add notes. Just to check, are you seeing a response when you add a note, indicating the new number of notes in the file, as below? Note that I am using a “.qo” file, which will cause notes to go Outbound from Notecard to Notehub.

{"req":"note.add", "file":"data.qo", "body":{"key":"value"}}
{"req":"note.add", "file":"data.qo", "body":{"key2":"value2"}}

If so, then the other requirement to send data is to set the ProductUID of your device. The ProductUID will identify the device on Notehub. For instance:

{"req":"hub.set", "product":"yamanoorsai_device"}

Once the productUID is set, the default mode of “periodic” should cause Notecard to connect to Notehub and upload your notes. If you log in to, create a project, and associate that project with your chosen ProductUID, you should see your notes under Events.

If you do not see them, then you may be experiencing a cellular connectivity problem. Please see this post for help in diagnosing this issue.

For future designs, you may find the design documentation for all of the Blues Notecarriers helpful. Schematics, BOMs, layouts, 3D models, Gebers, and more are available at GitHub - blues/note-hardware.


Thanks. When I ran the card.wireless command, it indicated that the modem is off. It is definitely a case of bad soldering.

I got the following output:

{“req”: “card.wireless”}

@John_Wiedey Your answer helped me troubleshoot the problem. It was just bad soldering. My design works now.

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Hey @yamanoorsai do you have those Eagle files in a public place you can share? I’d personally love to spin a few Pico carriers for myself. :smiley:

Not yet. I need to make a couple of changes to the notecard connector footprint and the design files themselves. They don’t have a mounting hole, test pads, or even silkscreen. I plan to make the corrections over the weekend, verify it and make the repository public.

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Sounds good. If you need another pair of eyes on it as you do, let me know. I have a personal Eagle license and need little excuse to fire it up. :smiley:

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I will take you up on that offer. I will send you the repo link via direct message once I complete it.