I have a 2 line pole display which is 20 characters on each line so total 40 characters (2x20) (ex. [url removed, login to view]) for which I do not have the model number or documentation.
I have a custom made PHP based POS (point of sales) system that I want to be able to write to the pole display to. The POS system is connected via USB to COM4 on the same system that has the local PHP installation.
I've tried many methods to do this and came up with my own solution using exec() and fwrite, the problem is I am having the following issues:
- Any string I write just prints out the first character (ex. I write test and it shows t)
- Any string I write gets appended to what is already on the screen (ex. if the screen has test and i write "test" again, it shows testt
- I am unable to read using fread what is already on the pole display. It just fails. I need to read what is on the display or be able to completely clear what is on the display.
So I need the following:
- A function to write the string to the pole display
- A function to either read what is on the pole display or clear the pole display completely
This should be simple for anyone who has experience so I am not paying a high amount, also I will be available by teamviewer to help debug.