Need urgent technical support for Nordic PMIC PM1300

[Hemanth0]

we are using nPM1300 EVK board for an upcoming project we are trying to interface PMIC PM1300 chip with Ambient Scientific processor GPx10 Pro.

It will be a huge setback for our project that is under development, if the I2C Interface between the two chips don’t work… since proto boards are already in fabrication

 

We have tested GPx10Pro I2C interface extensively with other sensors… but with this PMIC it is inconsistent and unreliable.  And this is the only part of Hardware that is not working yet.

In bare metal code, we are able to get acknowledgement sometimes. 

[Einar Thorsrud]

Hi,

As the I2C communication sometimes work but is unreliable the first thing that comes to mind is if you have long jumper wires when testing, perhaps combined with too weak pull-up resistors? I would suggest shortening the wires and using stronger (lower resistance) pull resistors.

[Hemanth0]

Hi,

we have tried with other pull up resistors still getting same results. we will once check by soldering the PMIC i2c pins with our mcu and will let you know the results.

[Hemanth0]

Hi below is the test setup fot the above observations.

[Einar Thorsrud]

Hi,

How do you power the nPM1300? I do not see a USB cable nor a battery connected to the EK. It needs to be powered.

Once ensuring that the device is powered (and assuming that is not an issue but just the case when the photo was taken), can you do the oscilloscope measurement close to the nPM1300 so that we see the SDA/SCL signal integrity (rise/fall time etc)?

[Hemanth0]

Hi,

We have provided power through the USB connection, which was not present in the previously shared image.

Additionally, we have attached the oscilloscope measurements of the SCL line captured close to the nPM1300 device. Could you please review the attached waveform and let us know if you observe any issues or have any recommendations?

[Einar Thorsrud]

Hi,

Hemanth0 said:

• VDDIO is supplied from our MCU, which is operating at 3.3V.
• On the P18 header, VDDIO is connected to VOUT2 through the onboard jumper.

This should not be done. Either supply VDDIO or connect VDDIO to VOIT2. You cannot do both at the same time.

Hemanth0 said:

Additionally, we have attached the oscilloscope measurements of the SCL line captured close to the nPM1300 device.

I am having problems making sense of the voltage levels there. Low should be 0 and high should be at VDDIO, which from what you write should be 3.3V.

[Hemanth0]

Hi,

Einar Thorsrud said:

This should not be done. Either supply VDDIO or connect VDDIO to VOIT2. You cannot do both at the same time

Yes, we have also tested the setup without connecting VDDIO and powered the board through USB only. However, we are still not receiving any response from the PMIC under this configuration.

Einar Thorsrud said:

I am having problems making sense of the voltage levels there. Low should be 0 and high should be at VDDIO, which from what you write should be 3.3V.

We are attaching an additional DSO measurements for your review. Could you please check them and share your observations? We have also verified the voltage levels, and they are stable at 3.3 V

[Hemanth0]

please find the attched DSO readings

[Einar Thorsrud]

Hi,

Thank you. This looks better than the last plot. What has changed since that? Can you show both the SDA and SCL line on the same plot, and clarify the conditions used here (VDDIO and VOIT2 configuration etc)?

[Hemanth0]

Hi,

we have connected USB cable for power supply to the board. VDDIO and VOUT2 are connected with onboard jumpers. we are facing some issues while reading SDA line when using baremetal code it is going low and not becoming high after communication is complete. we will capture using API and will send you ASAP.