I have an old VFD unit that has parallel and serial input, I am trying to use serial input to display text. I have found a simple "hello world" code for a similar VFD unit. My unit has 3 inputs VCC,SIN,Gnd, I have provided separate power to vfd, while Arduino connected to pc, both vfd and arduino share Gnd. By default the VFD unit goes into "test mode" if power connected. SIN is an active low input (SIN = 0 => active), which I have connected to arduino, I have another SIN input in parallel pins which I haven't touched.
Test mode image of VFD- IMGRUM - Lifestyle News - Health News
Example trying to use- http://www.planetarduino.org/?cat=673
Datasheet of the VFD- datasheet CU40066SCPB-S31A
Thanks for helping/reading
*All I want to do is send text to VFD unit via serial using arduino. In future I plan to use Esp8266 wifi module to display tweets on the vfd screen.