Python serial encoder to talk to PWP7000LT Daisy Wheel Printer. The intion of this code is to serve as a working reference for interfacing with this printer. Its not intended to be used as a complete general purpose driver, but it handles most plain text alright.
PWP7000
The program automatically adds line breaks and prompts the user to change to a new sheet of paper after 55 lines. At the end of the document, the form feed character is sent and the printer ejects the last sheet of paper.
The printer can do most ASCII printable characters, but it repurposes these ASCII characters as follows:
{ -> é
} -> ¼
\ -> ¿
| -> ½
< -> ¢
> -> ç
It also repurposes two control characters for two additional printable characters:
0x1E [RS] -> ¶
0x1F [US] -> §
The example code converts "1/2" and "1/4" to ½ and ¼ respectively. The code passes unicode bytes directly which results in unexpected results when those unicode bytes are non-ASCII, however.
The character spacing of the printer can also be adjusted with ASCII control characters. 0x0F [SI] reduces character spacing and 0x12 [TAPE] returns it to standard monospacing. In the reduced character spacing mode, spaces are still normal width. I don't include this in the example code since I haven't tested it out: I discovered this while using a microcontroller to print to the printer directly for a different project.