Cannot transmit serial data over UART0 in FRDM-KE02Z

[gschelotto]

Hello,

I'm trying to send data over UART0 in KE02Z board but I cannot get the Tx signal in the oscilloscope. I'm using KDS 1.1.0 and PE for the drivers initialization and management. I've created an AS1:AsynchroSerial component with the next configuration:

and checked all Initialization options.

The application code is:

AS1_Init();
AS1_SendChar('a');

At the end I expected to see the Tx signal of 'a' on PTB1 however I get a constant zero signal.

Did I miss something?

regards,

gaston

[gschelotto]

Hi Joern,

I thought I would have enough information with the FRDM-KE02Z User's Manual. I've just checked the schematics and you're right, lot of resistors are not populated by default.

Thank you!

regards,

gaston

[JPE · Accepted solution]

Hi Gaston,

by default, the transmitter of UART0 is connected to the infrared diode on the KE02Z Freedom board.

There is a small 0-ohm resistor R14, that has to be soldered on R15 (which should be empty).

The two resistors are placed between til KE02 and the jumper rows.

HTH, Joern

[gschelotto]

Strange, if I configure UART0 Tx as PTB1 everything goes well. However if it tied to PTA3 (PE allows both options) Tx pin does not work.

Previously I removed R45 and R42 and populated a couple of 0R in R39 and R47

Any suggestion?

regards,

gaston

[JPE]

I've not used that configuration of UART0 myself.

But if you have changed the resistors from R45 to R47 and from R42 to R39, then the hardware should be set up correctly to get access to UART0 via the connector J2.

Make sure, that no other functions are using the same pins.

To check the connection, you could also try to set up PTA2 and PTA3 as general purpose IOs and see, if you can toggle them.

[gschelotto]

Well, I've already done a toggle test over PTA3 with no success. There're no other resources that use this pin.

I'll post the issue in another thread and attach the KDS project.

thanks,

gaston