plug in usb, but system is not work

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Ryon
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plug in usb, but system is not work

hello,

when the battery reaches down to a certain point the device will go to hibernate mode.

when the device go to hibernate mode , i plug in the USB(VBUS),but the device did not seem to work.

as soon as voltage is detected over the VBUS, the device will switch the supply from the VBAT to the VBUS.

why the device was not work?

Device:
PM_Dialog
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Hi Ryon,

Hi Ryon,

Could you please indicate the part number that you are using? Is it DA14680/1 or DA14682/3?

Thanks, PM_Dialog

Ryon
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i am using DA14682.

i am using DA14682.

when the battery is empty,plug in the USB but the battery can not be charged and the system was not work.

as far as i know,we can not wake up the DA14682 with VBUS interrupt when the system entered hibernate mode.

So my question is:1. what mode will the system enter when the battery is empty?

2. when the battery reaches down to a certain point, the system will go to hibernate mode,but we can not wake up it with VBUS,So what should i do if i want to wake up the system?

PM_Dialog
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Hi Ryon,

Hi Ryon,

In case of DA14682/683 and hibernation mode, it’s not possible wake up the device via USB(VBUS). The only way to wake up from hibernation is via wake-up controller.

A possible solution to wake-up the DA14682 via VBUS (USB) interrupt might be to use the VBUS to trigger a GPIO by dividing VBUS with pull-up resistor and connecting GPIO with pull-down setting. The VBUS plugin could wakeup the system is by generating RST pulse when VBUS plugs in. Any GPIO can be used to wake the chip from hibernation. Another possible solution would be to use a C-R circuit in the VBUS line, that circuit generates a pulse that was applied to the RST pin. The same can be used for a GPIO.

Thanks, PM_Dialog

Ryon
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hello, PM_Dialog,

thank you for your reply,but there is another probelm here,when the battery is empty,plugging in the USB can not power the system and charge the battery.

as far as i know, as soon as voltage is detected over the VBUS, the device will switch the supply from the VBAT to the VBUS,right?

so why can not VBUS power the system?

Even if my target board does not have a battery, it should work fine when plugged in USB. Why does n’t it work when plugged in USB?

Ryon
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If you use the VBUS pin as a wake-up, it will crash. Have you tested it? What caused the crash?

PM_Dialog
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Hi Ryon.

Hi Ryon.

你能请检查如果你有连接t吗he D+ with the USBP and the D- with the USBN? According to datasheet, the USB controller has built-in hardware to determine the charger type to which it is connected. Depending on the charger type, battery state and USB connection state a defined current can be drawn from the charger. Are you running any of our SDK example, or you are running a custom code? Additionally, if you want to wake up the device via USB, you should do PCB modifications, as suggested in my previous comment. Are toggling a GPIO when the USB is plugged in?

Thanks, PM_Dialog