XIAO ble sense external Flash P25Q16H not detecting all the time

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Cemothy — Mon, 30 Mar 2026 14:12:59 GMT

Did you find a solution to this? I know this Post is 3 years old, but i am currently stuck at a similar issue with windbond external flash W25Q128JV and i really cant get to the bottom of this issue. If you have any insights or ideas please let me know.

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sigurd Hellesvik — Mon, 10 Jul 2023 13:33:08 GMT

[quote user="Sunil vignesh"]If I understood it correctly, are you asking how we can confirm if the device is working? If so, reading the JEDEC ID helps?[/quote]

Not exactly.

You said earlier that the QSPI Flash works some times, but other times it does not.

So get the difference between the "working QSPI flash" and "not workig QSPI flash" on a trace, and the difference might tell us something.

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sunil vignesh — Fri, 07 Jul 2023 14:05:36 GMT

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/435260"]Maybe there are some issues with the hardware connection of the external QSPI?[/quote]

I highly doubt it, as this behavior is same across all 4 XIAOs I've.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/435260"]Try to use a logic analyzer or oscilloscope trace of the QSPI lines.[/quote]

I'll try it.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/435260"]What is the difference between working communication and not?[/quote]

If I understood it correctly, are you asking how we can confirm if the device is working? If so, reading the JEDEC ID helps?

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sigurd Hellesvik — Fri, 07 Jul 2023 13:22:06 GMT

I got another idea to this:

Maybe there are some issues with the hardware connection of the external QSPI?
Try to use a logic analyzer or oscilloscope trace of the QSPI lines.

Are the signals clean or is there a lot of noise here?

What is the difference between working communication and not?

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sunil vignesh — Wed, 05 Jul 2023 14:05:16 GMT

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434665"]Looks like you changed the sample, right?[/quote]

That's right.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434665"]Does your device run a bootloader?[/quote]

Nope.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434665"]Try to put a short sleep before you check if the QSPI is ready. Does that help?[/quote]

No. That didn't helped either.

One interesting thing is, the above mentioned snippet worked as expected in the DK.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434665"]In that case, I assume that the sample did not work out-of-the-box?[/quote]

You've any theory on why you assume it might not works?

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sigurd Hellesvik — Wed, 05 Jul 2023 11:03:28 GMT

[quote user="Sunil vignesh"]I worked with this sample and it works until the DPD is not triggered. Once the device is suspended and resumed back, I'm getting the device busy.[/quote]

Looks like you changed the sample, right?
In that case, I assume that the sample did not work out-of-the-box?

Does your device run a bootloader?

Try to put a short sleep before you check if the QSPI is ready. Does that help?

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sunil vignesh — Tue, 04 Jul 2023 14:18:36 GMT

[quote userid="74103" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434276"]Does the JESD216 sample work for you?[/quote]

I worked with this sample and it works until the DPD is not triggered. Once the device is suspended and resumed back, I'm getting the device busy.

Modified snippet:

uint8_t id[3];

	rc = flash_read_jedec_id(dev, id);
	if (rc == 0) {
		printf("jedec-id = [%02x %02x %02x];\n",
		       id[0], id[1], id[2]);
	} else {
		printf("JEDEC ID read failed: %d\n", rc);
	}

	if (IS_ENABLED(DT_INST_PROP(0, has_dpd))) {
		printf("\n%s has_dpd", dev->name);
	}
	k_sleep(K_SECONDS(5));
	int ret = pm_device_action_run(dev, PM_DEVICE_ACTION_SUSPEND);
	k_sleep(K_SECONDS(5));
	ret = pm_device_action_run(dev, PM_DEVICE_ACTION_RESUME);
	rc = flash_read_jedec_id(dev, id);
	if (rc == 0) {
		printf("jedec-id = [%02x %02x %02x];\n",
		       id[0], id[1], id[2]);
	} else {
		printf("JEDEC ID read failed: %d\n", rc);
	}

	if (IS_ENABLED(DT_INST_PROP(0, has_dpd))) {
		printf("\n%s has_dpd", dev->name);
	}

Output:

*** Booting Zephyr OS build v3.2.99-ncs2 ***
jedec-id = [85 60 15];
JEDEC ID read failed: -16

If I soft reset nRF, the flash device is not even available to read, it comes back only the power is fully isolated and connected back.

Am I missing any startup sequence?

-Sunil

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sigurd Hellesvik — Tue, 04 Jul 2023 06:23:46 GMT

[quote user="Sunil vignesh"]You mean a time delay (K_SLEEP()) before checking?[/quote]

Yes

[quote user="Sunil vignesh"]Did you mean like MCUBOOT, NSIB?[/quote]

Yes

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sunil vignesh — Mon, 03 Jul 2023 15:14:01 GMT

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434202"]Could this be a timing issue?[/quote]

I'm assuming the same. As the flash is powered via GPIO, but not sure about it yet.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434202"]Try to put a short sleep before you check if the QSPI is ready. Does that help?[/quote]

You mean a time delay (K_SLEEP()) before checking?

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434202"]Does the JESD216 sample work for you?[/quote]

I'll work that out and let you know if it changes anything.

[quote userid="106736" url="~/f/nordic-q-a/101385/xiao-ble-sense-external-flash-p25q16h-not-detecting-all-the-time/434202"]Does your device run a bootloader?[/quote]

Did you mean like MCUBOOT, NSIB?

-Sunil.

RE: XIAO ble sense external Flash P25Q16H not detecting all the time

Sigurd Hellesvik — Mon, 03 Jul 2023 11:57:12 GMT

[quote user=""]Problem facing here - flash is not properly detecting all the time. on every soft reset or pin to reset . QSPI flash is not ready but when i powered off and put back ON after some time the QSPI ready and reading the data.[/quote]

Could this be a timing issue?
Try to put a short sleep before you check if the QSPI is ready. Does that help?

Does your device run a bootloader?

Does the JESD216 sample work for you?

Regards,
Sigurd Hellesvik