CLRC663 plus and RS232 Tx

[M_Chene]

Hello everyone,

I am trying to use a CLRC663 plus communiacting in RS232 with a MK20 µC. When I look the RX pin (IF0) with an oscilloscope I can observe the good communication frame (Sa, Address[0x7F],RD, So), but TX (IF2) stays at HIGH state...

IFSEL0 and 1 are set to ground and IF3 is connected to VDD according to the table in the evalboard's schematic. My communication speed is set to 115.2 Kb/s and I use a MAX3221 as level shifter.

Do you have any idea to this matter ?

Thanks in advance

Mathieu

[fangfang]

Hello,

That seems there is no the question of the CLRC663 depending on the datasheet as the link.

URL:https://www.nxp.com/docs/en/data-sheet/CLRC663.pdf.

That should be  related to the serial communication characteristics of kinetis . You may confirm it with  the kineti s engineers on kinetis community.

Hope it help you.

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[M_Chene]

Thank you for your answer,

I am sure that the  serial part of the MK20 is not the problem because it can do rs232 communication with others components I use. I made a diagram of how I connected my CLRC. Does this seem OK for you or did I misunderstand something in the datasheet on the RS232 connection (IF3 is connected to VDD and IFSEL pins to GND)?

Another thing that I want to verify is the frame I send. In the picture I wanted to read Command register (0x00). In yellow there is the signal in the RS232 part and in blue it is the signal between the MAX3221 and the CLRC663 plus

Does this frame seems good to you or must I send something before (it is the first time I use this component, so I don't think it is in Standby mode)?

Thank you in advance for your help.

Best regards

Mathieu