NRF52832 TWI electrical problem

[Vasily]

Good day.

I`m very new to nordic chips.

I`m try to use NRF52832 as TWI master with OLED display based on SSD1306 with I2C.

And got this.

Yellow is SCL, Blue is SDA. External pullups not used, speed 100k, TWI configuration is default from SDK 14.0 (as i know internal pullups is used).

I'm not using nordic dev board, just a module with nrf52832 from china. Schematics looks like this:

Power supply same for chips taken from ldo. Not sure about nrf52 capasitors and other stuff, board have a shield.

[MANGO]

Hi, Vasily. Have you connected SSD1306 with one of Nordic's development kit, such as PCA10040?

Can you upload your schematic? We need to know how those are connected to see what's the problem.

-Best Regards

[Vasily]

Hello Mango. I just update a post with information your are requested. Im not use nordic dev board, onlu module from china. Lines are not very long. Just 10 samtimeters.

[Turbo J]

Double check the ground connections of those scope probes. Some parts of the scope picture looks a lot like improper probe grounding. You also want to double check GPIO configuration of those TWI pins.

[MANGO]

Hi, Vasily. In that case, can you take a picture of your nRF module connected with the power line, the SSD1306 and the oscilloscope probe?

We cannot tell how the power is supplied by viewing this diagram.

-Best Regards

[Vasily]

Hello. Like TurboJ was recommended I was check all grounds in schematics. Problem was because bad ground on one pin of SEGGER came to oled display. just change them to another and display starts working. Oscillograms are also came good. Thank all for helping.