Connecting the npm1300 to a custom board

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Tue, 16 Apr 2024 08:23:52 GMT

Yes, that's what I wanted to know.

But with this approach, I can never get to the point where charging stops as soon as the algorithm determines the charge level to be 100%.

Let me give you an example.

I have a device that shows the charge level on the display in % (according to the fuel_gauge algorithm), and a LED (CHG) whose state depends on the algorithm of the PMIC itself.

And I constantly have the situation that the display shows 100% charge level, but the CHG LED does not go to off state because I(TERM) is still too high for the PMIC to finish charging. And this behavior of the device can be misleading for the end user, as he will not know which indicator to trust (LED or display).

I played around with the parameters in the overlay file (charge current and voltage), but I never managed to achieve a situation where the display shows 100% and the CHG LED turns off at the same time. Either 100% on the display and the LED is still on, or charging is turned off (LED turns off) but the algorithm shows less than 100% on the display.

Anyway, thanks Sigurd for your patience and help, you can consider this ticket closed as the existing problem is beyond the scope of this ticket.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Tue, 16 Apr 2024 07:01:32 GMT

[quote user="Sigurd Hellesvik"]I think V(TERM) is usually between 4.1V and 4.2V, but to be sure I have asked our PMIC experts.[/quote]

They say "The overlay file looks correct for his battery. "
And they add some bonus info: "Once Vbat reaches 4.2V nPM1300 will keep charging in CV mode (Vbat 4.2V) until charge current drops to 0.1C (10% of Ichg), above the customer battery limit of 0.01C (1% of Ichg)."

That is what you wanted to know, right?

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Tue, 16 Apr 2024 06:27:20 GMT

Hi.

I got it. Thanks for your answers.

This ticket can be considered closed.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Tue, 16 Apr 2024 05:56:14 GMT

[quote user="backstreet.devisor"]So I need to specify a lower value of V(TERM) than 4.2V (according to the technical documentation of the battery)? What is the usual value of V(TERM) set when charging such batteries? [/quote]

I think V(TERM) is usually between 4.1V and 4.2V, but to be sure I have asked our PMIC experts.

[quote user="backstreet.devisor"]When profiling the battery, I set the voltage to 4.2V and the charge current to 120mA. If I now change these parameters (voltage and current) in the overlay file for PMIC, will it affect the algorithm for calculating the battery charge?[/quote]

I do not quite understand why you ask this?
Myself, I do not know the algorithm, but it would make sense that changing the speed and max for a battery charge, you will affect the algorithm a bit. Like, it should show that you are done sooner if you choose 4.1V instead of 4.2V, no?

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Sun, 14 Apr 2024 17:47:44 GMT

One other thing I'm curious about...

When profiling the battery, I set the voltage to 4.2V and the charge current to 120mA. If I now change these parameters (voltage and current) in the overlay file for PMIC, will it affect the algorithm for calculating the battery charge?

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Fri, 12 Apr 2024 09:02:43 GMT

1. Measurement time about 50 minutes with an update period of 10 seconds.

2. I am using a 600 mAh LiPo battery. The technical documentation says:

Normal Voltage - 3.7V

Initial Voltage - 3.85-3.95V

Limited Charge Voltage - 4.2V

Standart Charging Current - 120 mA (0.2C)

Standart Charging Time - 6-7 hours

Standart Charging Method - 0.2C CC current charge to 4.2V, then CV charge till current declines to 0.01C.

Here is my overlay file with the PMIC charging settings:

npm1300_ek_charger: charger {
			compatible = "nordic,npm1300-charger";
			term-microvolt = <4200000>;
			current-microamp = <120000>;
			dischg-limit-microamp = <600000>;
			vbus-limit-microamp = <500000>;
			thermistor-ohms = <10000>;
			thermistor-beta = <3380>;
			charging-enable;
		};

So I need to specify a lower value of V(TERM) than 4.2V (according to the technical documentation of the battery)? What is the usual value of V(TERM) set when charging such batteries?

Thanks.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Fri, 12 Apr 2024 08:07:58 GMT

[quote user="backstreet.devisor"]1. Can you please confirm that these TTE values are normal?[/quote]

How long are these logs for (time)?

[quote user="backstreet.devisor"]How can I make it so that charging turns off immediately when SoC = 100%?[/quote]

So the Fuel Gauge library says that it "processes battery measurements made by Power Management ICs (PMICs) and provides a state-of-charge (SOC) prediction, along with other metric"

So it only reads out and does not control the charging.

The PMIC itself controls the charging, and it has a charge cutoff by its termination voltage.
Configure this to decide when charging should stop.

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Fri, 12 Apr 2024 06:21:58 GMT

Hi Sigurd.

Now the value of TTE and TTF are calculated. The text files contain TTE and TTF measurement results, the reading update time is 10 seconds.

1. Can you please confirm that these TTE values are normal?

devzone.nordicsemi.com/.../TTE.txt

2. TTF's readings look adequate and similar to the truth))

devzone.nordicsemi.com/.../TTF.txt

But pay attention to the moment when the charge percentage becomes 100% (current is 50 mA ).

The charging process does not stop because I(BAT) > I(TERM). In my case, the charging current is set to 120mA, so I(TERM) defaults to about 12mA (10% of I(CHG)). And the actual charging is only turned off after an additional 80 minutes when I(TERM) drops to 15 mA.

How can I make it so that charging turns off immediately when SoC = 100%?

I know I can set I(TERM) = 20% of I(CHG), but in that case I still have to wait a fair amount of time for I(BAT) to drop from 50mA to 25mA.

I'm hoping for your help.

Thank you.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Wed, 10 Apr 2024 07:00:37 GMT

The TTE=nan could be either an error with the floats themselves or with the print statement.
To check which:

Could you debug the application, and add a Watch for the tte and ttf values?

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Wed, 10 Apr 2024 06:27:24 GMT

Yeah, I initialized it.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Wed, 10 Apr 2024 06:21:06 GMT

A bit of a nitpick, but since your only red ring was where you included batter_model, it is good to check:

Did you remember to use it for the init as well?

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Tue, 09 Apr 2024 20:12:34 GMT

Hi Sigurd. Thank you for continuing to respond.

I put my battery file into the program.

And ran some tests.
Here is the result (on the screenshot). The time to update the readings is 1 minute.

As you can see, TTE and TTF are not displayed, although enough time has passed.

Perhaps this is due to the long refresh period of the readings (1 min)? What is the maximum update time I can set?

I set the refresh time to 1 second again and the TTE values displayed but were too unstable.

Thanks.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Mon, 08 Apr 2024 07:46:03 GMT

[quote user="backstreet.devisor"]but it doesn't answer my question. I already have my battery profile in .inc format and I want to figure out how I can integrate it into my final app.[/quote]

See here, and how they use the battery_model struct in the code.

If the PowerUP measurements still do not match after you have added the .inc, we can continue looking into that.
But for now, that is the prime suspect to what goes wrong

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Thu, 04 Apr 2024 13:27:55 GMT

Hi Sigurd.

[quote userid="106736" url="~/f/nordic-q-a/109699/connecting-the-npm1300-to-a-custom-board/477107"]That does not sound correct, no.
Do you see the same with a Development Kit, or is it only with the custom board?[/quote]

I observe this strange behavior both when using only nPM1300 EK when displaying charge level in nPM PowerUP, and when using custom board (host) + nPM1300 EK when displaying battery data via terminal.

[quote userid="106736" url="~/f/nordic-q-a/109699/connecting-the-npm1300-to-a-custom-board/477107"]I will check this, but i guess it is not.
Same as above: Do you see this with a DK?[/quote]

TTF is also not displayed both when using only EK and when using custom board + EK. And if you disconnect the charger, the time to discharge (TTE) is displayed incorrectly and jumps from 700 hours to 20 hours (using a 600 mAh battery), with only 1 LED on the user board constantly lit and i2C mode enabled.

[quote userid="106736" url="~/f/nordic-q-a/109699/connecting-the-npm1300-to-a-custom-board/477107"]Maybe this: Generating a battery model?[/quote]

This link doesn't explain how to integrate the .inc model into your own application. There is only this note,

but it doesn't answer my question. I already have my battery profile in .inc format and I want to figure out how I can integrate it into my final app.

Thanks.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Thu, 04 Apr 2024 12:48:15 GMT

[quote user="backstreet.devisor"]3. When I connect the battery (custom model profile) I see a different percentage of charge each time. For example, I connect the battery and the program shows 82 %, I immediately disconnect the EK from the computer and reconnect it and PowerUP shows already 88 % charge. On average, the charge value differs by 5% when you turn it on again. Is this normal program behavior or is something wrong?[/quote]

That does not sound correct, no.
Do you see the same with a Development Kit, or is it only with the custom board?

[quote user="backstreet.devisor"]4. The charging end time is almost never displayed when charging is turned on (see screenshot). Is this normal?[/quote]

I will check this, but i guess it is not.
Same as above: Do you see this with a DK?

[quote user="backstreet.devisor"]5. In the fuel_gauge example, there is a file called battery_model.inc in the src folder. I understand that this is the battery profile for the example. How do I add my own battery profile (which I already have)? Do I need to rename it to "battery_model" and replace the existing file or can I add it with an arbitrary name (for example, my_battery.inc)?[/quote]

Maybe this: Generating a battery model?

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Tue, 02 Apr 2024 13:52:29 GMT

All right, Sigurd, I'll wait for your reply.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Tue, 02 Apr 2024 13:50:36 GMT

Good to hear that you figured some of it out.
We are just back from Easter vacation, so I will get back to you on your questions in some days.

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Tue, 02 Apr 2024 05:28:31 GMT

Hi.

I've identified the reason the device wasn't not ready. The cause was a missing contact on the I2C line. I have also solved questions 1 and 2 (from the previous message).

But I would like to get answers to questions 3 and 4, as well as another new question:

5. In the fuel_gauge example, there is a file called battery_model.inc in the src folder. I understand that this is the battery profile for the example. How do I add my own battery profile (which I already have)? Do I need to rename it to "battery_model" and replace the existing file or can I add it with an arbitrary name (for example, my_battery.inc)?

Thanks.

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Thu, 28 Mar 2024 19:43:56 GMT

Hi. I also have additional questions:

1. When the nPM1300 EK is connected to the custom board and USB is connected to J3, should the CHG LED light up? Or will it only light up after initialization in the software? In my case, none of the LEDs are lit.

2. Should I2C be initialized (and include an I2C driver ) when connecting to a custom board? I got the I2C1 structure and checked for hardware readiness, there were no errors and I got the response "I2C bus i2c@40004000 is ready". So hopefully the error is not in the I2C1 line in that the npm1300 is not being detected.

And a couple more questions about EK behavior in nPM PowerUP:

3. When I connect the battery (custom model profile) I see a different percentage of charge each time. For example, I connect the battery and the program shows 82 %, I immediately disconnect the EK from the computer and reconnect it and PowerUP shows already 88 % charge. On average, the charge value differs by 5% when you turn it on again. Is this normal program behavior or is something wrong?

4. The charging end time is almost never displayed when charging is turned on (see screenshot). Is this normal?

I look forward to your help.

Thank you.

RE: Connecting the npm1300 to a custom board

backstreet.devisor — Wed, 27 Mar 2024 19:12:35 GMT

Hi Sigurd, thank you for your response.

Yes indeed, I didn't add that inclusion to the device tree file. After that, there was no error with the NPM1300_LDSW_MODE_LDSW detection.

But cmake errors were still present.

These errors were resolved by modifying the CMakeLists.txt file -->

# Copyright (c) 2023 Nordic Semiconductor ASA
# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause

cmake_minimum_required(VERSION 3.20.0)

set(SHIELD npm1300_ek)

find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
project(NONE)

# NORDIC SDK APP START
target_sources(app PRIVATE
  src/main.c
  src/fuel_gauge.c
)

# NORDIC SDK APP END
zephyr_library_include_directories(.)

After that, the project build went through without errors.

But the application terminates (return 0) after -->

if (!device_is_ready(charger)) {
		LOG_DBG("Charger device not ready.\n");
		return 0;
	}

Do you have any idea what this could be related to? All connections and jumpers are set according to the example.

Also, I would like to ask if it is mandatory to use npm1300_ek.overlay? What is the point of using the config.overlay file from nPM PowerUP if it will be overwritten by npm1300_ek.overlay?

Thanks.

RE: Connecting the npm1300 to a custom board

Sigurd Hellesvik — Wed, 27 Mar 2024 08:04:45 GMT

Hi,

Looks like NPM1300_LDSW_MODE_LDSW is not defined for that file.

So I searched for that in the nRF Connect SDK and found it used in zephyr/boards/shields/npm1300_ek/npm1300_ek.overlay.

At the top of this file, there is an include:

#include <dt-bindings/regulator/npm1300.h>

Could you by chance, be missing this?

Regards,
Sigurd Hellesvik