I'm not fan of asking in forums before having tested all possibilities...
Here is my problem: I've purchased a TTL mini thermal printer. I connected to launch a print test, and the printer LED blinks normally, it prints fast and fine. When I try to connect to the Raspberrypi2 model B. I'm following adafruit tutorial (Link), but unfortunately I cannot manage to print anything from the RaspPi.
From Left to Right: Labeled pins from the printer: GND - RX - TX - DTR - VH
I connected GND to USB ground and GND rasp PIN, and VH, to the USB red wire. I connected RX to TX pin from Raspi2. I connected TX to RX pin from Raspi2.
I'm not sure if the issue comes from the Ground connections... I'm totally lost here.
I'm using Raspbian.
I'll attach an image with the new connections [edited post with the new connection]:
Thanks for your time,