Serial Pi Plus not working
1890 Views - Created 02/01/2019
I am running Rasbian with latest Updates and Upgrades.
Below is my setup.
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p7 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait splash plymouth.ignore-serial-consoles quiet
End of /boot/config.txt:
In Raspberry configuration I have enabled the following interfaces:
The Serial Console is disabled
When doing the loopback test, connecting pins 2 & 3 in the DB9 and using either Putty or minicom with baud rate 9600 thru /dev/ttyS0, keystrokes are not echoed, nothing appears. I am doing this under sudo, so permissions shouldn’t be an issue. When connected to external device thru rs232 I can receive data but not able to send anything.
Are my settings correct?
Is there a way to debug the hardware to detect possible malfunction of the Serial Pi Plus?
Any advice on how to make the setup working?
Try commenting out the "enable_uart=1" line in the /boot/config.txt and use /dev/ttyAMA0 instead of ttyS0.
When you add the "dtoverlay=pi3-miniuart-bt" line to the /boot/config.txt it redirects the ttyAMA0 hardware UART port from the BlueTooth device to the UART pins on the GPIO header.
You may also need to disable hardware flow control in minicom for it to work correctly.
thanks for the quick reply.
However, it didn't help. No change in the behaviour.
Any other tricks to try?
If the UART port does echo the keystrokes then it could be a fault with the Serial Pi Plus and I will send you a replacement.
the second loopback test failed as well.
So I took a fresh Pi from the shelf and started all from scratch. Now the loopback with Serial Pi Plus works, with the above proposed configurations.
Thanks a lot for the support.
Note: documents in Portable Document Format (PDF) require Adobe Acrobat Reader 5.0 or higher to view, download Adobe Acrobat Reader or other PDF reading software for your computer or mobile device.