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Calling all dream killers

A project log for LoRaNeT32

WiFi/BLE --> LoRa bridge

morganmorgan 04/25/2017 at 23:522 Comments

hat dream is that I will one day soon click the magic button on @oshpark and have the first revision of LoRaNet32 merrily sent down the fab chain. But that dream cannot be realized without a few good stompings first.

There's been designs and redesigns of redesigns, mostly around the power system. I followed through with the change over to the CP2102N, that looks all fine. Where I fell short was in my hope to be able to have USB and Solar coexist and be happy and just work while charging the battery. I kept falling down a slippery slope of Ideal Diodes and Power Path management chips that cost a small fortune so I decided to dead simple. I put a switch between the solar input and VUSB.

Halp!

'm at the point where I really need more experience eyes looking at this. I'm sure there are piles of amateur mistakes that will stand out. A PDF of the schematics is in the project and there's a link to the KiCAD project.

Schematic

!!!!



There's still money left and there is still more people following than liking! Please help get those dollars for the prototype! Any Colored Button could also use some too!

Discussions

morgan wrote 04/26/2017 at 19:55 point

I've updated the images to better quality. I should also point out the Files section has a PDF of all the schematics. 

Available: https://cdn.hackaday.io/files/21067901330528/LoRaNeT32.pdf

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Blecky wrote 04/26/2017 at 09:41 point

I will be honest, I'm a bit lazy to go through each of the schematics (the colours also hurt my eyes), but the beauty of prototyped design is that you can always cut a couple of traces and put in some bodge wires and parts if you make a mistake (spot the bodge wire in my first revision, there's also a cut trace in there under the SD card - https://cdn.hackaday.io/images/7435141492517315886.jpg), then iterate the design. The biggest thing for your PCB is to import the design rules from OSHpark and make sure nothing too serious fails (track spacings and clearances mostly). Also try to avoid acute angles on any parts as it's good practice due to the fact the etchants can "pool" and etch away more in sharp corners.

Did you also get to look at the Linear LTC4077 or LTC4075HVX I posted in the chat? It is a little less efficient, but does have dual input.

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