nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Vidar Berg — Fri, 30 Dec 2022 10:59:46 GMT

Great! Thanks for confirming that it worked.

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

vincenttc — Fri, 30 Dec 2022 02:47:29 GMT

Thank, it works!

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Vidar Berg — Thu, 29 Dec 2022 10:39:48 GMT

Please try with the function below and see if you get the same result.

const struct device *gpio_dev = DEVICE_DT_GET(DT_NODELABEL(gpio0));

static inline void reset_to_bootloader()
{
    int err;
	err = gpio_pin_configure(gpio_dev, 19, GPIO_OUTPUT | GPIO_OUTPUT_INIT_LOW);
	if (err) {
		LOG_ERR("Failed to configure P0.19");
	}
}

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

vincenttc — Thu, 29 Dec 2022 10:02:11 GMT

Yes, I do not change the bootloader code and yes, the dongle will stay in DFU mode after press the reset button.
FYI, I am using ncs version 2.1.2 if helpful

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Vidar Berg — Thu, 29 Dec 2022 09:54:41 GMT

Hi,

I can't think of any obvious reasons for why it would exit DFU mode after a pin reset. Are you using the original pre-programmed bootloader on this dongle? And does it stay in DFU mode when you press the reset button?

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

vincenttc — Thu, 29 Dec 2022 09:50:52 GMT

Hi,

My fault. The dongle can be reset after pull down GPIO on P0.19, but the dongle will not hold on bootloader (blinking red led) but enter app instead. Is this under expectation?

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Vidar Berg — Thu, 29 Dec 2022 09:39:41 GMT

Hi,

It seems like the pull down on P0.19 is not strong enough to drive the reset line low. I suggest you configure P0.19 as an output instead.

Best regards,

Vidar

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

vincenttc — Thu, 29 Dec 2022 09:33:38 GMT

Hi,

Sorry that I also have the same problem and my dongle will not able to enable dfu mode after pull down P0.19

Would you help to check if any wrong with my code?

#define RESET_PIN    DT_GPIO_PIN(DT_ALIAS(resetpin), gpios)

static inline void reset_to_bootloader()
{
    gpio_pin_configure(dev, BIT(RESET_PIN), GPIO_INPUT | GPIO_PULL_DOWN);
}

dts:

buttons {
		compatible = "gpio-keys";
		button0: button_0 {
			gpios = <&gpio1 6 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 0";
		};
        button1: button_1 {
			gpios = <&gpio0 19 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 1";
		};
		...
	};
	
	aliases {
		sw0 = &button0;
		resetpin = &button1;
		...
		};

Thanks so much!

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Sasa Karanovic — Thu, 19 Aug 2021 20:33:34 GMT

Thank you!
Just confirming that pulling the GPIO P0.19 LOW sends the dongle into bootloader mode.

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Vidar Berg — Thu, 19 Aug 2021 17:19:12 GMT

Hi Sasa,

[quote userid="106385" url="~/f/nordic-q-a/78750/nrf52840-dongle-zephyr-jump-to-dfu-bootloader-buttonless/325794#325794"]Can you clarify in version of the datasheet/product guide was this note added?[/quote]

Forgot to include the link: Buttons and LEDs, sorry. This links to a chapter in the 52840 Dongle user guide.

[quote userid="106385" url="~/f/nordic-q-a/78750/nrf52840-dongle-zephyr-jump-to-dfu-bootloader-buttonless/325794#325794"]Is this feature (P0.19, P0.21, P0.23 and P.025 connected to RESET) available on all revisions of the nRF52840 dongle?[/quote]

Yes, it should be the same for all revisions. The schematic and layout files are available for download on the product page and there is no mention of these pins in the change log. But you can use P0.19 to be absolutely sure. This is the same pin we used in our DFU trigger library.

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Sasa Karanovic — Thu, 19 Aug 2021 15:20:53 GMT

Hi Vidar,

Thank you for clarifying this. Pulling the GPIO low seems like the easiest solution to implement.

Can you clarify in version of the datasheet/product guide was this note added? Is this feature (P0.19, P0.21, P0.23 and P.025 connected to RESET) available on all revisions of the nRF52840 dongle?

Thank you!

Sasa

RE: nRF52840 Dongle Zephyr: Jump to DFU/bootloader (buttonless)

Vidar Berg — Thu, 19 Aug 2021 13:22:49 GMT

Hello,

The DFU Trigger Library (USB) has not been ported to Zephyr, unfortunately. However, it should be fairly straight forward to put the dongle in DFU mode from the app, all you have you do is to pull either P0.19, P0.21, P0.23, or P0.25 low. These pins are connected toghether with the PINRESET pin (P0.18) so it should have the same effect as phyiscally pressing the reset button.

Best regards,

Vidar