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.

[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.

[Einar Thorsrud]

Hi,

Looking at the photo of the setup and what you have written again, there is a mistake that stands out. You should disconnect the jumper on P18, as described under VDDIO.

[Hemanth0]

Hi,
yess when we are powering up using USB, on P18 we are not connecting any jumpers on VDDIO.

[Einar Thorsrud]

Hi,

I see. To get a full and consise overview, can you share a photo of your current complete setup showing how both boards are powere, and the jumpwer configuration on the nPM EK? We need to ensure that both devices has the same VDD(IO) voltage. Can you also show a oscillioscope trace of both SDL and SDA in the same trace?

If the nPM EK is powered, configured correctly for the setup (so that the voltages are the same on both sides), and you write to it with the correct address (which I see you do from a previosu logic analyser trace), the nPM shoudl have acknliwledged. Is it still the case that it does work (at least you get the ack) about 8 out of 10 times? So the issue is stil intermittent?