UART Transmit/Receive implementation for unidirectional driver

rudycoppens — Mon, 16 Apr 2018 11:43:20 GMT

Hi all,

I am trying to make a RS485 connection with the use of a LTC2862A I use the "MKE14F512VLH16" The communication is working manually by setting one transceiver to transmit and the other to receive. It goes wrong when I try to switch from Receive to Transmit mode and back. The timing is never right and there comes no communication back on the bus. Here is an example code for, or has anyone an idea how to implement this. Now I implemented, set the slave device always to receive except when transmitting and the master the other way around. See the attached picture of the code.

Re: UART Transmit/Receive implementation for unidirectional driver

mjbcswitzerland — Mon, 16 Apr 2018 16:26:33 GMT

Hi Rudy

If you are switching the direction from transmitter to receiver you need to wait for the present transmission to terminate before doing so - to do this the TC flag (transmit complete) or its interrupt can be used.

See also chapter 11 of http://www.utasker.com/docs/MODBUS/uTasker_MODBUS.PDF for some details of how RS485 can be controlled without a direction signal.

Regards

Mark

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Kinetis Microcontrollers中的主题 UART Transmit/Receive implementation for unidirectional driver

UART Transmit/Receive implementation for unidirectional driver

Re: UART Transmit/Receive implementation for unidirectional driver