Hello,

I have been doing tests with Circuits.UART without result and without receiving any communication in ttyS0 or ttyAMA0

It seems that in Raspberry Pi Z the default port associated with GPIO 14 and 15 serial communication is ttyS0 and what worked for me on raspbian was to disable the console service of the ttyS0 port by stopping the service with sudo systemctl stop serial-getty@ttyS0.service and remove the line console = serial0,115200 from cmdline.txt

I have also seen in Nerves that in “config.txt” it is overlaying ttyAMA0 on ttyS0 with dtoverlay = pi3-miniuart-bt so that the GPIO serial port is ttyAMA0.

According to the documentation that I have read to use serial communication over GPIO without problems it is necessary to deactivate the console through raspi-config .

Bot Verification)

https://www.raspberrypi.org/documentation/configuration/uart.md

I have tried to modify cmdline.txt and config.txt removing the overlap dtoverlay = pi3-miniuart-bt and console=serial0,115200 editing the files directly on my MicroSD but it seems to affect how ssh communications are being mapped so I have not been able to log back in with ssh. If I undo the modifications by ssh circuits@ip or via USB ssh circuits@nerves.local I can log back into the system.

So I don’t know where to continue testing.

I think the key is to disable the serial port console, is there any way in nerves to stop this service or run sudo systemctl stop serial-getty@ttyAMA0.service for the ttyAMA0 port?