2017-06-07, 06:06 PM
It sounds like a typical hardware problem (noise, cable or ground problems).
Try to power the rpi with an 230V usb adapter or a powerbank. Connect only power and usb RS422 and try again.
Use wifi AP to access to your rpi. If it does work better try the adapter which didn't work.
Shut down everything on the 12 V side (also recharger) to reduce noise produced by other devices.
Some NMEA 0183 connections need resistors (ask google "Why and for what is 3 k ohm needed? NMEA").
Try to power the rpi with an 230V usb adapter or a powerbank. Connect only power and usb RS422 and try again.
Use wifi AP to access to your rpi. If it does work better try the adapter which didn't work.
Shut down everything on the 12 V side (also recharger) to reduce noise produced by other devices.
Some NMEA 0183 connections need resistors (ask google "Why and for what is 3 k ohm needed? NMEA").