During the OTA-DFU attempt, the BOOTLOADER cannot be woken up because the device is not rebooted.

[sunbae]

I'm developing a wearable device using nRF52832.
I am developing OTA-DFU nowadays. I have successfully tested the buttonless OTA-DFU using the nRF52-DK.

And I'm testing on my custom board and I have one problem.
My custom board has a soft power button.
My custom board is supplying 3V to the nRF52832 via LDO.
This custom board has one power button, commonly called soft power.

When this power button is pressed, 3V is supplied to the nRF52832 through the LDO, and the nRF52832 holds the LDO through one GPIO. It keeps the power supply.
When this button is pressed again, the nRF52832 sets GPIO (POWER HOLD) to LOW to disable the LDO, turning off the power.

In other words, when the power button is pressed, 3V power is supplied, and when it is pressed again, the power is turned off.
It's a toggled power button.

After all, at the OTS-DFU stage,
After the softdevice and bootloader are downloaded to the device, pairing DfuTarg to download the application is successful.

Since then I have tried OTA-DFU by pairing with the device (CANDY). The device must be rebooted, but will not turn on after the power is turned off.
Eventually the device will be turned off so it won't wake the bootloader.

The way I want
1. Do not reboot the device during OTA-DFU.
2. Or I need a way for the device to reboot normally during OTA-DFU.
(I.e. I need a way to keep the Power_Hold GPIO staying high on reboot.)

I wait for help
Thank you.

[Turbo J]

sunbae said:

V is supplied to the nRF52832 through the LDO, and the nRF52832 holds the LDO through one GPIO. It keeps the power supply.

The bootloader MUST do the same. Just add the corresponding line in the bootloaders main.c source file. You must do this pretty early, otherwise the LDO will turn off.

Now between the NVIC_SystemReset() and the bootloader turning on the LDO GPIO pin, the latter will probably be high impedance. You might want to use a capacitor to buffer the signal level a bit - I'd try 100nF first.