nPM1300 Battery Current Measurement

[jcoughlin_idl]

We've been evaluating the nPM1300 on a design and I was curious what register we should read to get the battery current. Any idea?

Section 7.1.1 of OPS v0.7 says single-shot measurements can be made for current, but I'm not seeing any register to read.

[Jared]

Hi,

You need to read out the BCHGISETMSB and BCHGISETLSB registers,

This register,

regards

Jared 

[jcoughlin_idl]

Hi Jared,

We're setting the charge limit via the registers you mentioned.

However, I'm more curious about the Battery Current single-shot measurement (using the 10-bit ADC) shown in the System monitor section. Any thoughts on what register we should read to do that?

Thanks
James

[Jared]

Ah I see, let me double check that with our developers,

I'll be back with more info

regards

Jared 

[Jared]

Hi again James,

I checked with our developers and there isn't any low level register that you can access direclty to get the battery current. Instead you need to use the nRF Fuel Gauge library in your nRF Connect SDK project and retrieve by using that API,

See the nRF Fuel Gauge sample for an example on how to use the API,

regards

Jared 

[jcoughlin_idl]

Hi Jared,

Thanks for the details! Great to see that there's a ncs fuel gauge sample as well. Few more questions:

- Is there any plan to make the current values accessible on a non-Zephyr system? We'd need the fuel gauging to work without Zephyr.
- Is the nPM1300 measuring the current onboard or is it an estimation?

James

[Jared]

Hi James,

Let me check with the developers,

regards

Jared 

[Devin Li]

Hi Jared,

I also faced the issue mentioned by James. I want to port the nRF fuel gauge code in ncs to nrf5 SDK, but found that the npm1300 fuel gauge code involved the zephyr/driver/sensor driver code.Do you have any more suggestions on this issue?

Regards,

Devin

[Jared]

Hi,

The short answer is that the nPM1300 is not supported in nRF5SDK,

Maybe it will be possible to backport the driver if the current values can be accessed directly, either way I'm still waiting for answer on this from our developers,

regards

Jared 

[Jared]

Hi James,

The nPM1300 is indeed measuring the current and not estimating it. I'm still waiting for answer on your first point regarding direct access to the Vbat current,

regards

Jared 

[Jared]

Hi James,

I discussed your first question regarding the future accessibility of direct access to the current measurement. The reply from our developers is that they couldn't answer roadmap questions and that it should be directed your region sales manager.

Do you have the contact details of your regional sales manger?

regards

Jared 

[jcoughlin_idl]

Hi Jared,

Thank you for looking into this. We have the contact info and we're in touch to learn more.

We have many products that have a Nordic part used for wireless communication alongside an application processor (from a different manufacturer) for everything else. Most of these products require current sensing, so I was excited to see current measurement listed as a feature in the product spec!

Locking the current measurement and fuel gauging to only work with the Nordic ecosystem would make it tough to move forward with the nPM1300 for those products.

-James

[Jared]

Hi James,

I totally understand you, this is feedback that you should definitely pass to the regional sales manager as well. 

I hope our team and yours can come to a solution that fits your requirements!

regards

Jared