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,

while using API's

while using baremetal:

npm_with_repeatstart.sal

Please find the details below regarding the I2C communication setup and observations:

• These are the pins we are using for the I2C communication between the MCU and the PMIC.
• 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.
• We are currently using 1.8 kΩ pull-up resistors on the SCL and SDA lines. We also tested with 10 kΩ pull-up resistors, but we are still not consistently receiving ACK from the PMIC.
• We have attached the Logic Analyzer (LA) results with protocol analysis enabled for reference.
• In the bare-metal implementation, we are able to receive ACK from the PMIC approximately 8 out of 10 times.
• No hardware changes were made during these tests.

i will share the DSO readings ASAP.

[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.