nRF5340 - untrust device_is_ready

RE: nRF5340 - untrust device_is_ready

Gabriele — Mon, 27 Nov 2023 08:27:56 GMT

Hello. Upgrading NCS to v2.5.0-3 fixes this issue.

RE: nRF5340 - untrust device_is_ready

Elfving — Mon, 30 Oct 2023 14:25:29 GMT

I am not sure, and I agree that this is strange.

Have you tried configuring it to shut down when the battery is detached, using THSH?

Regards,

Elfving

RE: nRF5340 - untrust device_is_ready

Gabriele — Thu, 26 Oct 2023 10:06:54 GMT

Hello Elfving,

When the battery is connected VBATSYS = VBAT = 4.19 V
When the battery is disconnected (circuit gets supplied by USB) VBATSYS = VBAT = 1.28 V
According to datasheet, the minimum operative voltage is V_BATT >= 2.3 V.
This would suffice to guarantee that the device cannot respond onto I2C bus, thus how can it be device_is_ready(dev) = 1 ?

RE: nRF5340 - untrust device_is_ready

Elfving — Mon, 23 Oct 2023 07:43:26 GMT

Hello Gabriele,

Could you try to measure the voltage on VBATSYS or SYS? A voltage on SYS should be enough to power BATT and the rest of the circuit.

From the datasheet of the MAX17262 it seems that it can be configured to shutdown when it detects that the battery is removed. It seems to me that it might be powered from the USB.

Regards,

Elfving

RE: nRF5340 - untrust device_is_ready

Gabriele — Thu, 12 Oct 2023 15:02:31 GMT

I did'n t check the DK.

This is a custom board. Hereunder the hardware schematic detail

As per as I know DK doesn't contain any fuel-gauge chip. Does it make sense to check it out ?

RE: nRF5340 - untrust device_is_ready

Elfving — Thu, 12 Oct 2023 14:46:08 GMT

That is odd. I asked about the sample because I managed to quickly check that I did not run into this issue myself when checking it with a DK yesterday. Maybe there was something I overlooked.

Are you seeing this with a DK as well? Are you trying this with a custom board?

Regards,

Elfving

RE: nRF5340 - untrust device_is_ready

Gabriele — Thu, 12 Oct 2023 09:59:15 GMT

The problem persists also with MAX17262 sample from Zephyr.

This is the main code:

/*
 * Copyright (c) 2020 Matija Tudan
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/sensor.h>

void main(void)
{
	const struct device *const dev = DEVICE_DT_GET_ONE(maxim_max17262);

	printk("device_is_ready is %d\n", device_is_ready(dev));

	if (!device_is_ready(dev)) {
		printk("sensor: device not ready.\n");
		return;
	}

	while (1) {
		struct sensor_value voltage, avg_current, temperature;
		float i_avg;

		sensor_sample_fetch(dev);
		sensor_channel_get(dev, SENSOR_CHAN_GAUGE_VOLTAGE, &voltage);
		sensor_channel_get(dev, SENSOR_CHAN_GAUGE_AVG_CURRENT,
						  &avg_current);
		sensor_channel_get(dev, SENSOR_CHAN_GAUGE_TEMP, &temperature);

		i_avg = avg_current.val1 + (avg_current.val2 / 1000000.0);

		printk("V: %d.%06d V; I: %f mA; T: %d.%06d °C\n",
		      voltage.val1, voltage.val2, (double)i_avg,
		      temperature.val1, temperature.val2);

		k_sleep(K_MSEC(1000));
	}
}

This is the console output:

RE: nRF5340 - untrust device_is_ready

Elfving — Wed, 11 Oct 2023 13:21:18 GMT

Hello Gabriele,

That is odd. Are you seeing the same thing with the basic fuel-gauge MAX17262 sample from zephyr?

Regards,

Elfving