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Posted: **Sun Apr 30, 2017 2:20 pm**

Hello all

Not sure if this should be in the bug report but I am having strange behaviour when using the delay function in conjunction with a UART.

As you can see from the flowcode image a 4mS delay is placed between UART sends but on the logic analyser image, measuring target hardware, it is actually 2mS. This is with a baud rate of 9600. Changing the baud rate to a higher speed makes the delay longer and it gets close to 4mS at 115200.

My clock is defined correctly at 16MHz.

Many thanks
Howard

FC 7.2.0.5
PIC18F46K22

: flowcode.JPG (51.32 KiB) Viewed 4968 times

Posted: **Mon May 01, 2017 3:09 pm**

The flowchart command sends the charaters to a buffer (SW, HW, both?) then waits 4 ms, the main process does not wait for the UART module to finish the job. This is why you see more pause at higher UART baudrate. I think.

: Delay time.jpg (36.14 KiB) Viewed 4952 times

Posted: **Wed May 03, 2017 10:33 am**

Thanks I understand now
regards
howard

Posted: **Wed May 03, 2017 11:02 am**

Hi Howard,

If you wanted to wait until the UART byte has finished being sent before starting your delay then you could use this following C code in a C icon.

UART Channel 1

Code: Select all

while (TXSTA1bits.TRMT);

UART Channel 2

Code: Select all

while (TXSTA2bits.TRMT);

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