Most of the time, salvaged VFDs aren't terribly useful because you need to figure out the right voltages then some way to drive it but I just salvaged a nice Samsung 20m101da1 VFD that's simple, only needs 5V DC and accepts serial or parallel data.
I powered it from a 5V adapter and sent text to it at 19200 baud from TeraTerm using a little USB to Serial TTL adapter and it worked.
At first the text would start at the right side of the display and scroll to the left but after messing with it for a while the text comes in from the left of the display the wraps around back to the start when it hits the right edge of the 20 characters. This is what the datasheet calls Normal Mode.
"5.2.7 DC1 (11 Hex) : Normal Display Mode
After writing a character, the write-in position is shifted to the right one digit automatically.
When the write-in position is on the least significant digit, the cursor moves to the most
significant digit."
I'd like to make it go back to how it was the first time but I need to send it the right ESC codes.
QUESTION:
What would be the simplest way to send
ESC (1B Hex) + DC3 (13 Hex) to switch to Horizontal Scroll Mode using something like TeraTerm?
I suppose I could connect the TX of an Arduino to it and send data to it that way but I'd like to see if it's possible with just the USB to Serial TTL adapter.
I can easily set this back to defaults by doing ESC (1B Hex) + "I" (49 Hex) because 0x49 is part of the standard ASCII characters but the setting I want to change requires me to send Hex values BELOW 0x20 which means that I can't just type it on a keyboard.
https://www.maltepoeggel.de/data/vfd/20m101da1.pdf