boost circuit is not working right


I created a project that is using a 328P to drive 24 LEDs (WS2812) which can draw 2A.
I used a guy to make a PCB layout (attached) and ordered an assembled version but something with the boost circuit is not working right. He used a LTC3872 (attached) to convert 3.7 to 5 but the circuit runs the battery down to 2.6 and then I get execution errors on the 328P. The LEDs are a very dynamic load so maybe the LTC3872 was a bad choice? Is there a chip that disconnects at 2.75 and then reconnects if the voltage is back to 3.7 (or some other threshold). The current circuit runs ok but simply does not protect the battery.

Any suggestions?


Schematics.pdf (1.13 MB)

3872fc-1267604.pdf (303 KB)

Why do you think the boost circuit is not working correctly?

How is the circuit supposed to monitor the battery, and what is it supposed to do when the voltage is low?

the expected behavior would be to disconnect the power, shut down.

The behavior is as expected, for a circuit without a battery monitor.

If you told "the guy" to include a battery monitoring circuit, it is not shown on the schematic.

That seems to be missing then. Do you have a suggestions how to do this right, maybe an example implementation?

The MCU can be programmed to read the battery voltage, and shut the circuit down. It would take a couple of fairly simple modifications to the PCB as well.

But why not talk to the guy?

no trust any more - Too many other issues with the pcb, this time I want to understand all details.
the 328P is powered by the booster itself so how would the new design look like?

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