USB - UART display


#1

Folks,

Had early problems using the USB to UART adapter but seems to be OK now but on occasions the terminal display does not read correctly.

Characters appear missed (don’t think they actually are) whch makes screen hard to read, line feeds don’t seem to work and lines get written over.

Tried putty and screen and both on occasions give this unreadable display on occasions.

Any ideas what this may be folks?

Geffers


#2

Is this with a Pi Zero W/Pi 3? Both devices, by default, use a software UART- reserving the hardware UART for Bluetooth. Since UART is a timing-sensitive protocol (there’s no clock line to reliably tell the host/client when a bit is present on the RX/TX lines) then it’s… well, sensitive to timing. And a software UART can have fluctuating timings that might produces bits that can be misread/dropped.

You should edit your /boot/config.txt and add:

dtoverlay=pi3-miniuart-bt

Or if you’re not using BT at all, you can use:

dtoverlay=pi3-disable-bt

(This also applies to the Zero W, despite the pi3 in the overlay name)


#3

Apologies for very late reply.

Running sudo screen /dev/ttyUSB0 115200 appeared to resolve all issues.

Geffers