Serial connection with Raspberry Pi Zero W

Hi…

I have a raspberry Pi Zero W attached to a DWM1001. They are attached via header pins 2, 4, 6, 8 & 10 so that I can send serial commands from the Pi to the DWM1001.

I am trying to send serial shell API commands to the DWM1001. It seems as though I can only send a max of about 6 characters. Any commands less than this seem to work fine. I get a full response without and truncation. But commands longer than 6 won’t go though.

ex…

echo -e “si\r” > /dev/serial0

This works as only 3 chars are required…

this get truncated…

echo -e “aps 12 34 56\r” > /dev/serial0

Only the “aps 12” gets through.

I thought maybe it was a buffer size issue or even the miniuart. I switched off the blue tooth and swapped the miniuart with the good one but it didn’t seem to make much difference.

-Console is disable via cmdline.txt
-uart is enabled via config.txt
-bt is off via config.txt
-hciuart service is disabled

If anyone has any idea why I am getting this truncation I would really appreciate the help.

Thanks,
Pat