I have a strange issue I cannot figure out. I have a thermal printer (https://www.adafruit.com/products/597) plugged to the UART (/dev/ttyAMAO).
I configured the RPi to remove the console on
/dev/ttyAMA0 with the following:
echo "dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait" > /boot/cmdline.txt systemctl disable serial-getty@ttyAMA0.service
My project is running fine, except for one little thing.
Immediately after powering the RPi, the printer sometimes prints 5 random characters, as if something was sent to the UART.
Any idea from where it's coming from?
Additional info: - the RPi is a model B - it runs Raspbian Jessie Lite