MKE04Z8VWJ4 UART0 TX issue

[yibinwang]

I used MKE04Z8VWJ4 to do a small UART application to send and read the data from PC. Now, the Reading is okay. But, the sending is not OK. I have many times to check my code and board. There is not any issue of I found. Who can help me and give me some tips on something i missing?

[Robin_Shen]

Hi yibin

PTA2 and PTA3 are true open-drain pins when operated as output.

If you configure the PTA3 as UART0_TX function, you need to be aware it.

Best Regard

Robin

[yibinwang]

Hi Robin Shen,

Yes, you are 100% right. We need to add a pull up resistor for the TX pin.

Thank again.

Jerry

Jerry Wang | 王宜斌 | Software Engineer | Branson Ultrasonics

Emerson Industrial Automation | No. 21, XueShi Road | New industrial Park | Hi-tech Zone | Xi'an | CHINA

T +86 (29) 8928 0532 | M 13891803152

Jerryw.Wang@emerson.com<mailto:Jerryw.Wang@emerson.com>

[mjbcswitzerland]

Hi

Carefully check the pin configuration used.

The KE famiy use a priority system for the selected function on each pin and you may have set the pin as Tx output but there could still be a function with higher priority set, which will overwrite it.

Regards

Mark